diff mbox

[v2,2/5] clk: samsung: Add support to register rate_table for PLL3xxx

Message ID 1369834677-20312-3-git-send-email-vikas.sajjan@linaro.org
State New
Headers show

Commit Message

Vikas C Sajjan May 29, 2013, 1:37 p.m. UTC
From: Yadwinder Singh Brar <yadi.brar@samsung.com>

This patch defines a common rate_table which will contain recommended p, m, s,
k values for supported rates that needs to be changed for changing
corresponding PLL's rate.

Signed-off-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
---
 drivers/clk/samsung/clk-exynos4.c    |    8 ++++----
 drivers/clk/samsung/clk-exynos5250.c |   14 +++++++-------
 drivers/clk/samsung/clk-pll.c        |   14 ++++++++++++--
 drivers/clk/samsung/clk-pll.h        |   33 +++++++++++++++++++++++++++++++--
 4 files changed, 54 insertions(+), 15 deletions(-)

Comments

Doug Anderson May 29, 2013, 11:44 p.m. UTC | #1
Vikas / Yadwinder,

On Wed, May 29, 2013 at 6:37 AM, Vikas Sajjan <vikas.sajjan@linaro.org> wrote:
> From: Yadwinder Singh Brar <yadi.brar@samsung.com>
>
> This patch defines a common rate_table which will contain recommended p, m, s,
> k values for supported rates that needs to be changed for changing
> corresponding PLL's rate.
>
> Signed-off-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
> ---
>  drivers/clk/samsung/clk-exynos4.c    |    8 ++++----
>  drivers/clk/samsung/clk-exynos5250.c |   14 +++++++-------
>  drivers/clk/samsung/clk-pll.c        |   14 ++++++++++++--
>  drivers/clk/samsung/clk-pll.h        |   33 +++++++++++++++++++++++++++++++--
>  4 files changed, 54 insertions(+), 15 deletions(-)

I also reviewed this in our gerrit
<https://gerrit.chromium.org/gerrit/#/c/56742/>, but I'll summarize
here for the list...

>  struct clk * __init samsung_clk_register_pll35xx(const char *name,
> -                       const char *pname, const void __iomem *base)
> +                       const char *pname, const void __iomem *base,
> +                       const struct samsung_pll_rate_table *rate_table,
> +                       const unsigned int rate_count)

Feels like you should document here that rate_table needs to be sorted
and the sort order.

> +struct samsung_pll_rate_table {
> +       unsigned  int rate;

nit: extra space before "int" should be removed.

Also: you can include rate here if you need a convenient place to
store it (which sadly means that this structure can't be const).
...but I do like Tomasz's idea of actually calculating it.  You can't
know it at compile time since the parent rate comes from the device
tree.

compatible = "samsung,clock-xxti";
clock-frequency = <24000000>;

> +       unsigned int pdiv;
> +       unsigned int mdiv;
> +       unsigned int sdiv;
> +       unsigned int kdiv;

I think kdiv is signed.

-Doug
Yadwinder Singh Brar May 30, 2013, 6:55 a.m. UTC | #2
Hi Doug,

On Thu, May 30, 2013 at 5:14 AM, Doug Anderson <dianders@chromium.org> wrote:
> Vikas / Yadwinder,
>
> On Wed, May 29, 2013 at 6:37 AM, Vikas Sajjan <vikas.sajjan@linaro.org> wrote:
>> From: Yadwinder Singh Brar <yadi.brar@samsung.com>
>>
>> This patch defines a common rate_table which will contain recommended p, m, s,
>> k values for supported rates that needs to be changed for changing
>> corresponding PLL's rate.
>>
>> Signed-off-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
>> ---
>>  drivers/clk/samsung/clk-exynos4.c    |    8 ++++----
>>  drivers/clk/samsung/clk-exynos5250.c |   14 +++++++-------
>>  drivers/clk/samsung/clk-pll.c        |   14 ++++++++++++--
>>  drivers/clk/samsung/clk-pll.h        |   33 +++++++++++++++++++++++++++++++--
>>  4 files changed, 54 insertions(+), 15 deletions(-)
>
> I also reviewed this in our gerrit
> <https://gerrit.chromium.org/gerrit/#/c/56742/>, but I'll summarize
> here for the list...
>
>>  struct clk * __init samsung_clk_register_pll35xx(const char *name,
>> -                       const char *pname, const void __iomem *base)
>> +                       const char *pname, const void __iomem *base,
>> +                       const struct samsung_pll_rate_table *rate_table,
>> +                       const unsigned int rate_count)
>
> Feels like you should document here that rate_table needs to be sorted
> and the sort order.
>

sure,  we will add comment  to sort the table in descending order.

>> +struct samsung_pll_rate_table {
>> +       unsigned  int rate;
>
> nit: extra space before "int" should be removed.
>

ok

> Also: you can include rate here if you need a convenient place to
> store it (which sadly means that this structure can't be const).
> ...but I do like Tomasz's idea of actually calculating it.  You can't
> know it at compile time since the parent rate comes from the device
> tree.
>
> compatible = "samsung,clock-xxti";
> clock-frequency = <24000000>;
>

Actually this table should contain the recommended values
and if we see the user manual, the input(parent) rate is also a part
of recommended
table of different output rate for a particular PLL for that SoC.

So as Tomasz said input(parent) rate may change with board,
then, do those corresponding recommended p, m, s, k will be valid?

In case, input(parent) rate changes then we may need different set of p, m ,s, k
values recommended for new input rate to get required(recommended to
use) output rate.

So, we think its better that the p, m, s and k along with the parent
is known at the compile time ( or DT ?),
as these p, m, s, k values are very much coupled with the parent rate
to achieve the
 required(recommended to use) output rate.

Also, since the sorted table is required (sorted based on "rate"),
its better to have the rate in a const rate table.

And the whole set of recommended values should come from same place(DT
or static table),
to keep the things simple and consistent.

Moreover, practically for a particular SoC , we use the recommended
input(parent) rate only for a PLL.
So we should keep the things simple here presently.

>> +       unsigned int pdiv;
>> +       unsigned int mdiv;
>> +       unsigned int sdiv;
>> +       unsigned int kdiv;
>
> I think kdiv is signed.
>

No, as these values should be the recommended values to be written in
corresponding  register bits. So it should remain unsigned.

K value should be considered as negative only while recalculating rate.

As per exynos5250 user manual's section 7.3.2 :
" K value description "Postive value (Negative value)":
Postive values is that you should write EPLLCON/VPLLCON register.
Negative value is that you can calculate PLL output frequency with it."

> -Doug

Regards,
Yadwinder & Vikas.
Doug Anderson May 30, 2013, 3:55 p.m. UTC | #3
Yadwinder and Vikas,

On Wed, May 29, 2013 at 11:55 PM, Yadwinder Singh Brar
<yadi.brar01@gmail.com> wrote:
>> Also: you can include rate here if you need a convenient place to
>> store it (which sadly means that this structure can't be const).
>> ...but I do like Tomasz's idea of actually calculating it.  You can't
>> know it at compile time since the parent rate comes from the device
>> tree.
>>
>> compatible = "samsung,clock-xxti";
>> clock-frequency = <24000000>;
>>
>
> Actually this table should contain the recommended values
> and if we see the user manual, the input(parent) rate is also a part
> of recommended
> table of different output rate for a particular PLL for that SoC.

That's a reasonable point.  It's not clear to me whether the
recommended PMSK values would be the same or different if the input
wasn't 24MHz.  You're assuming that they would be different and that
seems fair given my (limited) understanding of the electrical
characteristics of PLLs.

...so if a given SoC needed to support multiple different parent clock
frequencies the presumably it would have multiple tables and pick the
right one to pass in.


> So as Tomasz said input(parent) rate may change with board,
> then, do those corresponding recommended p, m, s, k will be valid?
>
> In case, input(parent) rate changes then we may need different set of p, m ,s, k
> values recommended for new input rate to get required(recommended to
> use) output rate.
>
> So, we think its better that the p, m, s and k along with the parent
> is known at the compile time ( or DT ?),
> as these p, m, s, k values are very much coupled with the parent rate
> to achieve the
>  required(recommended to use) output rate.

Having the rate in the table definitely makes it easier to understand,
too.  We just have to hope someone doesn't mess up in their
calculation.  Worst case we could put some error checking somewhere.


> Also, since the sorted table is required (sorted based on "rate"),
> its better to have the rate in a const rate table.

You _could_ still sort the table based on eventually rate even if the
actual rate wasn't in the table.  ...but I agree that it's harder to
look at and figure out.


> And the whole set of recommended values should come from same place(DT
> or static table),
> to keep the things simple and consistent.

Agree that it's a little weird now that some bits of the clock code is
in the device tree and some bits are just static tables in code.
...but I think that's OK for now.

Perhaps a reasonable compromise is to include "24mhz" in the name of
the tables (in later patches) and then give a WARN_ON if the xxti
clock isn't 24MHz.  Then you've effectively documented the plan of
action should someone eventually need a different xxti clock.


> Moreover, practically for a particular SoC , we use the recommended
> input(parent) rate only for a PLL.
> So we should keep the things simple here presently.

From what I've seen so far I could totally believe Samsung releasing a
new user manual in the future that provides instructions for using a
non-24MHz xxti clock.  ...but with all of the above I think we've got
a reasonable story so I think we're good.


>>> +       unsigned int pdiv;
>>> +       unsigned int mdiv;
>>> +       unsigned int sdiv;
>>> +       unsigned int kdiv;
>>
>> I think kdiv is signed.
>>
>
> No, as these values should be the recommended values to be written in
> corresponding  register bits. So it should remain unsigned.
>
> K value should be considered as negative only while recalculating rate.
>
> As per exynos5250 user manual's section 7.3.2 :
> " K value description "Postive value (Negative value)":
> Postive values is that you should write EPLLCON/VPLLCON register.
> Negative value is that you can calculate PLL output frequency with it."

OK, fair point.  We can keep it unsigned in this table.


To summarize where I think we are in this series, I'm hoping for one
more version that:
* Adds a comment about the rate table being sorted (and which direction)
* Adds "24mhz" to the variable name for the PLL tables in future patch series
* Adds a WARN_ON if the xxti clock isn't 24MHz


Does that sound like a plan?  Tomasz: any thoughts on the above?


-Doug
Tomasz Figa June 3, 2013, 3:25 p.m. UTC | #4
Hi Yadwinder,

On Thursday 30 of May 2013 12:25:40 Yadwinder Singh Brar wrote:
> Hi Doug,
> 
> On Thu, May 30, 2013 at 5:14 AM, Doug Anderson <dianders@chromium.org> 
wrote:
> > Vikas / Yadwinder,
> > 
> > On Wed, May 29, 2013 at 6:37 AM, Vikas Sajjan <vikas.sajjan@linaro.org> 
wrote:
> >> From: Yadwinder Singh Brar <yadi.brar@samsung.com>
> >> 
> >> This patch defines a common rate_table which will contain recommended p,
> >> m, s, k values for supported rates that needs to be changed for changing
> >> corresponding PLL's rate.
> >> 
> >> Signed-off-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
> >> ---
> >> 
> >>  drivers/clk/samsung/clk-exynos4.c    |    8 ++++----
> >>  drivers/clk/samsung/clk-exynos5250.c |   14 +++++++-------
> >>  drivers/clk/samsung/clk-pll.c        |   14 ++++++++++++--
> >>  drivers/clk/samsung/clk-pll.h        |   33
> >>  +++++++++++++++++++++++++++++++-- 4 files changed, 54 insertions(+), 15
> >>  deletions(-)
> > 
> > I also reviewed this in our gerrit
> > <https://gerrit.chromium.org/gerrit/#/c/56742/>, but I'll summarize
> > here for the list...
> > 
> >>  struct clk * __init samsung_clk_register_pll35xx(const char *name,
> >> 
> >> -                       const char *pname, const void __iomem *base)
> >> +                       const char *pname, const void __iomem *base,
> >> +                       const struct samsung_pll_rate_table *rate_table,
> >> +                       const unsigned int rate_count)
> > 
> > Feels like you should document here that rate_table needs to be sorted
> > and the sort order.
> 
> sure,  we will add comment  to sort the table in descending order.
> 
> >> +struct samsung_pll_rate_table {
> >> +       unsigned  int rate;
> > 
> > nit: extra space before "int" should be removed.
> 
> ok
> 
> > Also: you can include rate here if you need a convenient place to
> > store it (which sadly means that this structure can't be const).
> > ...but I do like Tomasz's idea of actually calculating it.  You can't
> > know it at compile time since the parent rate comes from the device
> > tree.
> > 
> > compatible = "samsung,clock-xxti";
> > clock-frequency = <24000000>;
> 
> Actually this table should contain the recommended values
> and if we see the user manual, the input(parent) rate is also a part
> of recommended
> table of different output rate for a particular PLL for that SoC.

From what I understood in the documentation is that there is a set of 
recommended P, M, S (, K) tuples for each PLL and they are not dependent on 
input frequency - f_in and f_out are provided in the table just for reference 
to see the relation between output frequency and input frequency.

I think we should ask some H/W engineer about that to make sure and choose the 
proper implementation, which will work properly for future cases, instead of 
ending with something that works just with current cases.

Best regards,
Doug Anderson June 3, 2013, 8:58 p.m. UTC | #5
Tomasz,

On Mon, Jun 3, 2013 at 8:25 AM, Tomasz Figa <t.figa@samsung.com> wrote:

> From what I understood in the documentation is that there is a set of
> recommended P, M, S (, K) tuples for each PLL and they are not dependent on
> input frequency - f_in and f_out are provided in the table just for reference
> to see the relation between output frequency and input frequency.
>
> I think we should ask some H/W engineer about that to make sure and choose the
> proper implementation, which will work properly for future cases, instead of
> ending with something that works just with current cases.

Hopefully you and Yadwinder can take this on?  You probably have
better access to the right people to ask.

I did dig up my 4210 manual which actually has one place where it
shows two options for FIN of VPLL: 24MHz and 27MHz.  They don't seem
to share any PMSK values that are the same.

It seems like the tables were generated by choosing a bunch of
frequencies that people would probably like to make and then finding
the best way to make that frequency (probably backed up by a bunch of
simulation and testing of that exact combination).


We have landed most of this series of patches (with a few
modifications to later patches to avoid adding a global alias)..
...but if you decided to go a different way we'll take your version of
course (either now with a revert / re-pick or when we rebase later).

:)

-Doug
Yadwinder Singh Brar June 4, 2013, 11:32 a.m. UTC | #6
Hi Tomasz,

On Mon, Jun 3, 2013 at 8:55 PM, Tomasz Figa <t.figa@samsung.com> wrote:
> Hi Yadwinder,
>
> On Thursday 30 of May 2013 12:25:40 Yadwinder Singh Brar wrote:
>> Hi Doug,
>>
>> On Thu, May 30, 2013 at 5:14 AM, Doug Anderson <dianders@chromium.org>
> wrote:
>> > Vikas / Yadwinder,
>> >
>> > On Wed, May 29, 2013 at 6:37 AM, Vikas Sajjan <vikas.sajjan@linaro.org>
> wrote:
>> >> From: Yadwinder Singh Brar <yadi.brar@samsung.com>
>> >>
>> >> This patch defines a common rate_table which will contain recommended p,
>> >> m, s, k values for supported rates that needs to be changed for changing
>> >> corresponding PLL's rate.
>> >>
>> >> Signed-off-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
>> >> ---
>> >>
>> >>  drivers/clk/samsung/clk-exynos4.c    |    8 ++++----
>> >>  drivers/clk/samsung/clk-exynos5250.c |   14 +++++++-------
>> >>  drivers/clk/samsung/clk-pll.c        |   14 ++++++++++++--
>> >>  drivers/clk/samsung/clk-pll.h        |   33
>> >>  +++++++++++++++++++++++++++++++-- 4 files changed, 54 insertions(+), 15
>> >>  deletions(-)
>> >
>> > I also reviewed this in our gerrit
>> > <https://gerrit.chromium.org/gerrit/#/c/56742/>, but I'll summarize
>> > here for the list...
>> >
>> >>  struct clk * __init samsung_clk_register_pll35xx(const char *name,
>> >>
>> >> -                       const char *pname, const void __iomem *base)
>> >> +                       const char *pname, const void __iomem *base,
>> >> +                       const struct samsung_pll_rate_table *rate_table,
>> >> +                       const unsigned int rate_count)
>> >
>> > Feels like you should document here that rate_table needs to be sorted
>> > and the sort order.
>>
>> sure,  we will add comment  to sort the table in descending order.
>>
>> >> +struct samsung_pll_rate_table {
>> >> +       unsigned  int rate;
>> >
>> > nit: extra space before "int" should be removed.
>>
>> ok
>>
>> > Also: you can include rate here if you need a convenient place to
>> > store it (which sadly means that this structure can't be const).
>> > ...but I do like Tomasz's idea of actually calculating it.  You can't
>> > know it at compile time since the parent rate comes from the device
>> > tree.
>> >
>> > compatible = "samsung,clock-xxti";
>> > clock-frequency = <24000000>;
>>
>> Actually this table should contain the recommended values
>> and if we see the user manual, the input(parent) rate is also a part
>> of recommended
>> table of different output rate for a particular PLL for that SoC.
>
> From what I understood in the documentation is that there is a set of
> recommended P, M, S (, K) tuples for each PLL and they are not dependent on
> input frequency - f_in and f_out are provided in the table just for reference
> to see the relation between output frequency and input frequency.
>

If input rate(f_in) gets changed for PLL, then the corresponding
output rates(f_out)
will change by using same(common) set of  recommended P, M, S (, K),
and the new set of  output rates(f_out) may not be the _required_ set
of target rates.
So we need different set of P, M, S (,K) values for different f_in.

Table should contain set of P, M, S (,K) values for the _required_
target(f_out) rates
for a particular input(f_in) rate.

> I think we should ask some H/W engineer about that to make sure and choose the
> proper implementation, which will work properly for future cases, instead of
> ending with something that works just with current cases.
>

We already asked hardware engineer about PMS values for PLL,
and we got a table containing recommended  P, M ,S values for a given
f_in(24 MHz)
and required f_out rates.

Please let me know, why you think we are specific to current cases only ?

Regards,
Yadwinder

> Best regards,
> --
> Tomasz Figa
> Linux Kernel Developer
> Samsung R&D Institute Poland
> Samsung Electronics
>
>> So as Tomasz said input(parent) rate may change with board,
>> then, do those corresponding recommended p, m, s, k will be valid?
>>
>> In case, input(parent) rate changes then we may need different set of p, m
>> ,s, k values recommended for new input rate to get required(recommended to
>> use) output rate.
>>
>> So, we think its better that the p, m, s and k along with the parent
>> is known at the compile time ( or DT ?),
>> as these p, m, s, k values are very much coupled with the parent rate
>> to achieve the
>>  required(recommended to use) output rate.
>>
>> Also, since the sorted table is required (sorted based on "rate"),
>> its better to have the rate in a const rate table.
>>
>> And the whole set of recommended values should come from same place(DT
>> or static table),
>> to keep the things simple and consistent.
>>
>> Moreover, practically for a particular SoC , we use the recommended
>> input(parent) rate only for a PLL.
>> So we should keep the things simple here presently.
>>
>> >> +       unsigned int pdiv;
>> >> +       unsigned int mdiv;
>> >> +       unsigned int sdiv;
>> >> +       unsigned int kdiv;
>> >
>> > I think kdiv is signed.
>>
>> No, as these values should be the recommended values to be written in
>> corresponding  register bits. So it should remain unsigned.
>>
>> K value should be considered as negative only while recalculating rate.
>>
>> As per exynos5250 user manual's section 7.3.2 :
>> " K value description "Postive value (Negative value)":
>> Postive values is that you should write EPLLCON/VPLLCON register.
>> Negative value is that you can calculate PLL output frequency with it."
>>
>> > -Doug
>>
>> Regards,
>> Yadwinder & Vikas.
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc"
>> in the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
Tomasz Figa June 5, 2013, 1:40 p.m. UTC | #7
Hi Yadwinder,

On Tuesday 04 of June 2013 17:02:48 Yadwinder Singh Brar wrote:
> Hi Tomasz,
> 
> On Mon, Jun 3, 2013 at 8:55 PM, Tomasz Figa <t.figa@samsung.com> wrote:
> > Hi Yadwinder,
> > 
> > On Thursday 30 of May 2013 12:25:40 Yadwinder Singh Brar wrote:
> >> Hi Doug,
> >> 
> >> On Thu, May 30, 2013 at 5:14 AM, Doug Anderson <dianders@chromium.org>
> > 
> > wrote:
> >> > Vikas / Yadwinder,
> >> > 
> >> > On Wed, May 29, 2013 at 6:37 AM, Vikas Sajjan <vikas.sajjan@linaro.org>
> > 
> > wrote:
> >> >> From: Yadwinder Singh Brar <yadi.brar@samsung.com>
> >> >> 
> >> >> This patch defines a common rate_table which will contain recommended
> >> >> p,
> >> >> m, s, k values for supported rates that needs to be changed for
> >> >> changing
> >> >> corresponding PLL's rate.
> >> >> 
> >> >> Signed-off-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
> >> >> ---
> >> >> 
> >> >>  drivers/clk/samsung/clk-exynos4.c    |    8 ++++----
> >> >>  drivers/clk/samsung/clk-exynos5250.c |   14 +++++++-------
> >> >>  drivers/clk/samsung/clk-pll.c        |   14 ++++++++++++--
> >> >>  drivers/clk/samsung/clk-pll.h        |   33
> >> >>  +++++++++++++++++++++++++++++++-- 4 files changed, 54 insertions(+),
> >> >>  15
> >> >>  deletions(-)
> >> > 
> >> > I also reviewed this in our gerrit
> >> > <https://gerrit.chromium.org/gerrit/#/c/56742/>, but I'll summarize
> >> > here for the list...
> >> > 
> >> >>  struct clk * __init samsung_clk_register_pll35xx(const char *name,
> >> >> 
> >> >> -                       const char *pname, const void __iomem *base)
> >> >> +                       const char *pname, const void __iomem *base,
> >> >> +                       const struct samsung_pll_rate_table
> >> >> *rate_table,
> >> >> +                       const unsigned int rate_count)
> >> > 
> >> > Feels like you should document here that rate_table needs to be sorted
> >> > and the sort order.
> >> 
> >> sure,  we will add comment  to sort the table in descending order.
> >> 
> >> >> +struct samsung_pll_rate_table {
> >> >> +       unsigned  int rate;
> >> > 
> >> > nit: extra space before "int" should be removed.
> >> 
> >> ok
> >> 
> >> > Also: you can include rate here if you need a convenient place to
> >> > store it (which sadly means that this structure can't be const).
> >> > ...but I do like Tomasz's idea of actually calculating it.  You can't
> >> > know it at compile time since the parent rate comes from the device
> >> > tree.
> >> > 
> >> > compatible = "samsung,clock-xxti";
> >> > clock-frequency = <24000000>;
> >> 
> >> Actually this table should contain the recommended values
> >> and if we see the user manual, the input(parent) rate is also a part
> >> of recommended
> >> table of different output rate for a particular PLL for that SoC.
> > 
> > From what I understood in the documentation is that there is a set of
> > recommended P, M, S (, K) tuples for each PLL and they are not dependent
> > on
> > input frequency - f_in and f_out are provided in the table just for
> > reference to see the relation between output frequency and input
> > frequency.
> 
> If input rate(f_in) gets changed for PLL, then the corresponding
> output rates(f_out)
> will change by using same(common) set of  recommended P, M, S (, K),
> and the new set of  output rates(f_out) may not be the _required_ set
> of target rates.
> So we need different set of P, M, S (,K) values for different f_in.
> 
> Table should contain set of P, M, S (,K) values for the _required_
> target(f_out) rates
> for a particular input(f_in) rate.

I'm not sure what required rates you are talking about. For most PLLs the list 
of available frequencies seems to be defined by the set of supported PMS values 
and those are the frequencies that can be set by consumers, not the other way 
around.

There are some cases when some particular frequency must be generated, like 
PLLs used for audio or video clock sources, but this just means that there 
must be an entry in PMS table that gives PLL configuration which produces such 
frequency with used PLL input clock.

> > I think we should ask some H/W engineer about that to make sure and choose
> > the proper implementation, which will work properly for future cases,
> > instead of ending with something that works just with current cases.
> 
> We already asked hardware engineer about PMS values for PLL,
> and we got a table containing recommended  P, M ,S values for a given
> f_in(24 MHz)
> and required f_out rates.

This doesn't answer the question about using those PMS values with different 
input rate.

Kukjin, maybe you can give some information on this or point to a person who 
could?

> Please let me know, why you think we are specific to current cases only ?

I don't like the idea of having separate tables for each input rate. Just 
imagine how much data would have to be added if boards with several different 
input rates showed up.

Sure, if each input rate requires different set of PMS values by hardware 
design, it can't be helped, but if the same PMS values can be reused (even 
giving different output rates, but this is usually not important), one table 
can be used for all cases.

Best regards,
Yadwinder Singh Brar June 6, 2013, 9:01 a.m. UTC | #8
On Wed, Jun 5, 2013 at 7:10 PM, Tomasz Figa <t.figa@samsung.com> wrote:
> Hi Yadwinder,
>
> On Tuesday 04 of June 2013 17:02:48 Yadwinder Singh Brar wrote:
>> Hi Tomasz,
>>
>> On Mon, Jun 3, 2013 at 8:55 PM, Tomasz Figa <t.figa@samsung.com> wrote:
>> > Hi Yadwinder,
>> >
>> > On Thursday 30 of May 2013 12:25:40 Yadwinder Singh Brar wrote:
>> >> Hi Doug,
>> >>
>> >> On Thu, May 30, 2013 at 5:14 AM, Doug Anderson <dianders@chromium.org>
>> >
>> > wrote:
>> >> > Vikas / Yadwinder,
>> >> >
>> >> > On Wed, May 29, 2013 at 6:37 AM, Vikas Sajjan <vikas.sajjan@linaro.org>
>> >
>> > wrote:
>> >> >> From: Yadwinder Singh Brar <yadi.brar@samsung.com>
>> >> >>
>> >> >> This patch defines a common rate_table which will contain recommended
>> >> >> p,
>> >> >> m, s, k values for supported rates that needs to be changed for
>> >> >> changing
>> >> >> corresponding PLL's rate.
>> >> >>
>> >> >> Signed-off-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
>> >> >> ---
>> >> >>
>> >> >>  drivers/clk/samsung/clk-exynos4.c    |    8 ++++----
>> >> >>  drivers/clk/samsung/clk-exynos5250.c |   14 +++++++-------
>> >> >>  drivers/clk/samsung/clk-pll.c        |   14 ++++++++++++--
>> >> >>  drivers/clk/samsung/clk-pll.h        |   33
>> >> >>  +++++++++++++++++++++++++++++++-- 4 files changed, 54 insertions(+),
>> >> >>  15
>> >> >>  deletions(-)
>> >> >
>> >> > I also reviewed this in our gerrit
>> >> > <https://gerrit.chromium.org/gerrit/#/c/56742/>, but I'll summarize
>> >> > here for the list...
>> >> >
>> >> >>  struct clk * __init samsung_clk_register_pll35xx(const char *name,
>> >> >>
>> >> >> -                       const char *pname, const void __iomem *base)
>> >> >> +                       const char *pname, const void __iomem *base,
>> >> >> +                       const struct samsung_pll_rate_table
>> >> >> *rate_table,
>> >> >> +                       const unsigned int rate_count)
>> >> >
>> >> > Feels like you should document here that rate_table needs to be sorted
>> >> > and the sort order.
>> >>
>> >> sure,  we will add comment  to sort the table in descending order.
>> >>
>> >> >> +struct samsung_pll_rate_table {
>> >> >> +       unsigned  int rate;
>> >> >
>> >> > nit: extra space before "int" should be removed.
>> >>
>> >> ok
>> >>
>> >> > Also: you can include rate here if you need a convenient place to
>> >> > store it (which sadly means that this structure can't be const).
>> >> > ...but I do like Tomasz's idea of actually calculating it.  You can't
>> >> > know it at compile time since the parent rate comes from the device
>> >> > tree.
>> >> >
>> >> > compatible = "samsung,clock-xxti";
>> >> > clock-frequency = <24000000>;
>> >>
>> >> Actually this table should contain the recommended values
>> >> and if we see the user manual, the input(parent) rate is also a part
>> >> of recommended
>> >> table of different output rate for a particular PLL for that SoC.
>> >
>> > From what I understood in the documentation is that there is a set of
>> > recommended P, M, S (, K) tuples for each PLL and they are not dependent
>> > on
>> > input frequency - f_in and f_out are provided in the table just for
>> > reference to see the relation between output frequency and input
>> > frequency.
>>
>> If input rate(f_in) gets changed for PLL, then the corresponding
>> output rates(f_out)
>> will change by using same(common) set of  recommended P, M, S (, K),
>> and the new set of  output rates(f_out) may not be the _required_ set
>> of target rates.
>> So we need different set of P, M, S (,K) values for different f_in.
>>
>> Table should contain set of P, M, S (,K) values for the _required_
>> target(f_out) rates
>> for a particular input(f_in) rate.
>
> I'm not sure what required rates you are talking about. For most PLLs the list
> of available frequencies seems to be defined by the set of supported PMS values
> and those are the frequencies that can be set by consumers, not the other way
> around.
>
> There are some cases when some particular frequency must be generated, like
> PLLs used for audio or video clock sources, but this just means that there
> must be an entry in PMS table that gives PLL configuration which produces such
> frequency with used PLL input clock.
>

Yes, I was talking about same cases. Perhaps,I think it holds true in general
for PLLs, whose set_rate can be called.

>> > I think we should ask some H/W engineer about that to make sure and choose
>> > the proper implementation, which will work properly for future cases,
>> > instead of ending with something that works just with current cases.
>>
>> We already asked hardware engineer about PMS values for PLL,
>> and we got a table containing recommended  P, M ,S values for a given
>> f_in(24 MHz)
>> and required f_out rates.
>
> This doesn't answer the question about using those PMS values with different
> input rate.
>
> Kukjin, maybe you can give some information on this or point to a person who
> could?
>
>> Please let me know, why you think we are specific to current cases only ?
>
> I don't like the idea of having separate tables for each input rate. Just
> imagine how much data would have to be added if boards with several different
> input rates showed up.
>

I think by declaring all these different table as __init,
and creating a copy to be used while registering, we can
save a little memory as well as the unnecessary cost which
we have to bear while doing set_rate() and round_rate()
by using single big table(for some time critical cases).

> Sure, if each input rate requires different set of PMS values by hardware
> design, it can't be helped, but if the same PMS values can be reused (even
> giving different output rates, but this is usually not important), one table
> can be used for all cases.
>

Its good to know whether same PMS values can be reused, from hardware guys.

Using different tables we can always blindly stick to recommended values without
bothering much every time, whether existing PMS can be reused or not
while adding new cases.

>> Regards,
>> Yadwinder
>>
>> > Best regards,
>> > --
>> > Tomasz Figa
>> > Linux Kernel Developer
>> > Samsung R&D Institute Poland
>> > Samsung Electronics
>> >
>> >> So as Tomasz said input(parent) rate may change with board,
>> >> then, do those corresponding recommended p, m, s, k will be valid?
>> >>
>> >> In case, input(parent) rate changes then we may need different set of p,
>> >> m
>> >> ,s, k values recommended for new input rate to get required(recommended
>> >> to
>> >> use) output rate.
>> >>
>> >> So, we think its better that the p, m, s and k along with the parent
>> >> is known at the compile time ( or DT ?),
>> >> as these p, m, s, k values are very much coupled with the parent rate
>> >> to achieve the
>> >>
>> >>  required(recommended to use) output rate.
>> >>
>> >> Also, since the sorted table is required (sorted based on "rate"),
>> >> its better to have the rate in a const rate table.
>> >>
>> >> And the whole set of recommended values should come from same place(DT
>> >> or static table),
>> >> to keep the things simple and consistent.
>> >>
>> >> Moreover, practically for a particular SoC , we use the recommended
>> >> input(parent) rate only for a PLL.
>> >> So we should keep the things simple here presently.
>> >>
>> >> >> +       unsigned int pdiv;
>> >> >> +       unsigned int mdiv;
>> >> >> +       unsigned int sdiv;
>> >> >> +       unsigned int kdiv;
>> >> >
>> >> > I think kdiv is signed.
>> >>
>> >> No, as these values should be the recommended values to be written in
>> >> corresponding  register bits. So it should remain unsigned.
>> >>
>> >> K value should be considered as negative only while recalculating rate.
>> >>
>> >> As per exynos5250 user manual's section 7.3.2 :
>> >> " K value description "Postive value (Negative value)":
>> >> Postive values is that you should write EPLLCON/VPLLCON register.
>> >> Negative value is that you can calculate PLL output frequency with it."
>> >>
>> >> > -Doug
>> >>
>> >> Regards,
>> >> Yadwinder & Vikas.
>> >> --
>> >> To unsubscribe from this list: send the line "unsubscribe
>> >> linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org
>> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc"
>> in the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
Tomasz Figa June 8, 2013, 11:58 a.m. UTC | #9
On Thursday 06 of June 2013 14:31:56 Yadwinder Singh Brar wrote:
> On Wed, Jun 5, 2013 at 7:10 PM, Tomasz Figa <t.figa@samsung.com> wrote:
> > Hi Yadwinder,
> > 
> > On Tuesday 04 of June 2013 17:02:48 Yadwinder Singh Brar wrote:
> >> Hi Tomasz,
> >> 
> >> On Mon, Jun 3, 2013 at 8:55 PM, Tomasz Figa <t.figa@samsung.com> 
wrote:
> >> > Hi Yadwinder,
> >> > 
> >> > On Thursday 30 of May 2013 12:25:40 Yadwinder Singh Brar wrote:
> >> >> Hi Doug,
> >> >> 
> >> >> On Thu, May 30, 2013 at 5:14 AM, Doug Anderson
> >> >> <dianders@chromium.org>
> >> > 
> >> > wrote:
> >> >> > Vikas / Yadwinder,
> >> >> > 
> >> >> > On Wed, May 29, 2013 at 6:37 AM, Vikas Sajjan
> >> >> > <vikas.sajjan@linaro.org>
> >> > 
> >> > wrote:
> >> >> >> From: Yadwinder Singh Brar <yadi.brar@samsung.com>
> >> >> >> 
> >> >> >> This patch defines a common rate_table which will contain
> >> >> >> recommended
> >> >> >> p,
> >> >> >> m, s, k values for supported rates that needs to be changed for
> >> >> >> changing
> >> >> >> corresponding PLL's rate.
> >> >> >> 
> >> >> >> Signed-off-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
> >> >> >> ---
> >> >> >> 
> >> >> >>  drivers/clk/samsung/clk-exynos4.c    |    8 ++++----
> >> >> >>  drivers/clk/samsung/clk-exynos5250.c |   14 +++++++-------
> >> >> >>  drivers/clk/samsung/clk-pll.c        |   14 ++++++++++++--
> >> >> >>  drivers/clk/samsung/clk-pll.h        |   33
> >> >> >>  +++++++++++++++++++++++++++++++-- 4 files changed, 54
> >> >> >>  insertions(+),
> >> >> >>  15
> >> >> >>  deletions(-)
> >> >> > 
> >> >> > I also reviewed this in our gerrit
> >> >> > <https://gerrit.chromium.org/gerrit/#/c/56742/>, but I'll
> >> >> > summarize
> >> >> > here for the list...
> >> >> > 
> >> >> >>  struct clk * __init samsung_clk_register_pll35xx(const char
> >> >> >>  *name,
> >> >> >> 
> >> >> >> -                       const char *pname, const void __iomem
> >> >> >> *base)
> >> >> >> +                       const char *pname, const void __iomem
> >> >> >> *base,
> >> >> >> +                       const struct samsung_pll_rate_table
> >> >> >> *rate_table,
> >> >> >> +                       const unsigned int rate_count)
> >> >> > 
> >> >> > Feels like you should document here that rate_table needs to be
> >> >> > sorted
> >> >> > and the sort order.
> >> >> 
> >> >> sure,  we will add comment  to sort the table in descending order.
> >> >> 
> >> >> >> +struct samsung_pll_rate_table {
> >> >> >> +       unsigned  int rate;
> >> >> > 
> >> >> > nit: extra space before "int" should be removed.
> >> >> 
> >> >> ok
> >> >> 
> >> >> > Also: you can include rate here if you need a convenient place
> >> >> > to
> >> >> > store it (which sadly means that this structure can't be const).
> >> >> > ...but I do like Tomasz's idea of actually calculating it.  You
> >> >> > can't
> >> >> > know it at compile time since the parent rate comes from the
> >> >> > device
> >> >> > tree.
> >> >> > 
> >> >> > compatible = "samsung,clock-xxti";
> >> >> > clock-frequency = <24000000>;
> >> >> 
> >> >> Actually this table should contain the recommended values
> >> >> and if we see the user manual, the input(parent) rate is also a
> >> >> part
> >> >> of recommended
> >> >> table of different output rate for a particular PLL for that SoC.
> >> > 
> >> > From what I understood in the documentation is that there is a set
> >> > of
> >> > recommended P, M, S (, K) tuples for each PLL and they are not
> >> > dependent on
> >> > input frequency - f_in and f_out are provided in the table just for
> >> > reference to see the relation between output frequency and input
> >> > frequency.
> >> 
> >> If input rate(f_in) gets changed for PLL, then the corresponding
> >> output rates(f_out)
> >> will change by using same(common) set of  recommended P, M, S (, K),
> >> and the new set of  output rates(f_out) may not be the _required_ set
> >> of target rates.
> >> So we need different set of P, M, S (,K) values for different f_in.
> >> 
> >> Table should contain set of P, M, S (,K) values for the _required_
> >> target(f_out) rates
> >> for a particular input(f_in) rate.
> > 
> > I'm not sure what required rates you are talking about. For most PLLs
> > the list of available frequencies seems to be defined by the set of
> > supported PMS values and those are the frequencies that can be set by
> > consumers, not the other way around.
> > 
> > There are some cases when some particular frequency must be generated,
> > like PLLs used for audio or video clock sources, but this just means
> > that there must be an entry in PMS table that gives PLL configuration
> > which produces such frequency with used PLL input clock.
> 
> Yes, I was talking about same cases. Perhaps,I think it holds true in
> general for PLLs, whose set_rate can be called.

Not really. For PLLs used for general purpose clocking, like for CPU or 
GPU, there is usually no need to achieve certain frequency. Actually you 
might want to have as many as possible intermediate steps to improve 
frequency scaling efficiency.

> >> > I think we should ask some H/W engineer about that to make sure and
> >> > choose the proper implementation, which will work properly for
> >> > future cases, instead of ending with something that works just
> >> > with current cases.>> 
> >> We already asked hardware engineer about PMS values for PLL,
> >> and we got a table containing recommended  P, M ,S values for a given
> >> f_in(24 MHz)
> >> and required f_out rates.
> > 
> > This doesn't answer the question about using those PMS values with
> > different input rate.
> > 
> > Kukjin, maybe you can give some information on this or point to a
> > person who could?
> > 
> >> Please let me know, why you think we are specific to current cases
> >> only ?> 
> > I don't like the idea of having separate tables for each input rate.
> > Just imagine how much data would have to be added if boards with
> > several different input rates showed up.
> 
> I think by declaring all these different table as __init,
> and creating a copy to be used while registering, we can
> save a little memory as well as the unnecessary cost which
> we have to bear while doing set_rate() and round_rate()
> by using single big table(for some time critical cases).

Well, this is not really about memory, but rather the amount of code in 
the driver. The amount of memory needed for such setting table is rather 
insignificant.

> > Sure, if each input rate requires different set of PMS values by
> > hardware design, it can't be helped, but if the same PMS values can
> > be reused (even giving different output rates, but this is usually
> > not important), one table can be used for all cases.
> 
> Its good to know whether same PMS values can be reused, from hardware
> guys.

Another thing worth knowing would be whether a different frequency of 
input clock is really allowed or the SoC supports only 24 MHz. If the 
latter is the case, then there is no need to bother supporting other 
frequencies.

I'm waiting for some opinion from hardware engineers then.

Best regards,
Tomasz

> Using different tables we can always blindly stick to recommended values
> without bothering much every time, whether existing PMS can be reused
> or not while adding new cases.
> 
> >> Regards,
> >> Yadwinder
> >> 
> >> > Best regards,
> >> > --
> >> > Tomasz Figa
> >> > Linux Kernel Developer
> >> > Samsung R&D Institute Poland
> >> > Samsung Electronics
> >> > 
> >> >> So as Tomasz said input(parent) rate may change with board,
> >> >> then, do those corresponding recommended p, m, s, k will be valid?
> >> >> 
> >> >> In case, input(parent) rate changes then we may need different set
> >> >> of p, m
> >> >> ,s, k values recommended for new input rate to get
> >> >> required(recommended
> >> >> to
> >> >> use) output rate.
> >> >> 
> >> >> So, we think its better that the p, m, s and k along with the
> >> >> parent
> >> >> is known at the compile time ( or DT ?),
> >> >> as these p, m, s, k values are very much coupled with the parent
> >> >> rate
> >> >> to achieve the
> >> >> 
> >> >>  required(recommended to use) output rate.
> >> >> 
> >> >> Also, since the sorted table is required (sorted based on "rate"),
> >> >> its better to have the rate in a const rate table.
> >> >> 
> >> >> And the whole set of recommended values should come from same
> >> >> place(DT
> >> >> or static table),
> >> >> to keep the things simple and consistent.
> >> >> 
> >> >> Moreover, practically for a particular SoC , we use the
> >> >> recommended
> >> >> input(parent) rate only for a PLL.
> >> >> So we should keep the things simple here presently.
> >> >> 
> >> >> >> +       unsigned int pdiv;
> >> >> >> +       unsigned int mdiv;
> >> >> >> +       unsigned int sdiv;
> >> >> >> +       unsigned int kdiv;
> >> >> > 
> >> >> > I think kdiv is signed.
> >> >> 
> >> >> No, as these values should be the recommended values to be written
> >> >> in
> >> >> corresponding  register bits. So it should remain unsigned.
> >> >> 
> >> >> K value should be considered as negative only while recalculating
> >> >> rate.
> >> >> 
> >> >> As per exynos5250 user manual's section 7.3.2 :
> >> >> " K value description "Postive value (Negative value)":
> >> >> Postive values is that you should write EPLLCON/VPLLCON register.
> >> >> Negative value is that you can calculate PLL output frequency with
> >> >> it."
> >> >> 
> >> >> > -Doug
> >> >> 
> >> >> Regards,
> >> >> Yadwinder & Vikas.
> >> >> --
> >> >> To unsubscribe from this list: send the line "unsubscribe
> >> >> linux-samsung-soc" in the body of a message to
> >> >> majordomo@vger.kernel.org More majordomo info at 
> >> >> http://vger.kernel.org/majordomo-info.html>> 
> >> --
> >> To unsubscribe from this list: send the line "unsubscribe
> >> linux-samsung-soc" in the body of a message to
> >> majordomo@vger.kernel.org
> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
> --
> To unsubscribe from this list: send the line "unsubscribe
> linux-samsung-soc" in the body of a message to
> majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/drivers/clk/samsung/clk-exynos4.c b/drivers/clk/samsung/clk-exynos4.c
index cf7d4e7..beff8a1 100644
--- a/drivers/clk/samsung/clk-exynos4.c
+++ b/drivers/clk/samsung/clk-exynos4.c
@@ -1021,13 +1021,13 @@  void __init exynos4_clk_init(struct device_node *np, enum exynos4_soc exynos4_so
 					reg_base + VPLL_CON0, pll_4650c);
 	} else {
 		apll = samsung_clk_register_pll35xx("fout_apll", "fin_pll",
-					reg_base + APLL_LOCK);
+					reg_base + APLL_LOCK, NULL, 0);
 		mpll = samsung_clk_register_pll35xx("fout_mpll", "fin_pll",
-					reg_base + E4X12_MPLL_LOCK);
+					reg_base + E4X12_MPLL_LOCK, NULL, 0);
 		epll = samsung_clk_register_pll36xx("fout_epll", "fin_pll",
-					reg_base + EPLL_LOCK);
+					reg_base + EPLL_LOCK, NULL, 0);
 		vpll = samsung_clk_register_pll36xx("fout_vpll", "fin_pll",
-					reg_base + VPLL_LOCK);
+					reg_base + VPLL_LOCK, NULL, 0);
 	}
 
 	samsung_clk_add_lookup(apll, fout_apll);
diff --git a/drivers/clk/samsung/clk-exynos5250.c b/drivers/clk/samsung/clk-exynos5250.c
index 687b580..ddf10ca 100644
--- a/drivers/clk/samsung/clk-exynos5250.c
+++ b/drivers/clk/samsung/clk-exynos5250.c
@@ -491,19 +491,19 @@  void __init exynos5250_clk_init(struct device_node *np)
 			ext_clk_match);
 
 	apll = samsung_clk_register_pll35xx("fout_apll", "fin_pll",
-			reg_base);
+			reg_base, NULL, 0);
 	mpll = samsung_clk_register_pll35xx("fout_mpll", "fin_pll",
-			reg_base + 0x4000);
+			reg_base + 0x4000, NULL, 0);
 	bpll = samsung_clk_register_pll35xx("fout_bpll", "fin_pll",
-			reg_base + 0x20010);
+			reg_base + 0x20010, NULL, 0);
 	gpll = samsung_clk_register_pll35xx("fout_gpll", "fin_pll",
-			reg_base + 0x10050);
+			reg_base + 0x10050, NULL, 0);
 	cpll = samsung_clk_register_pll35xx("fout_cpll", "fin_pll",
-			reg_base + 0x10020);
+			reg_base + 0x10020, NULL, 0);
 	epll = samsung_clk_register_pll36xx("fout_epll", "fin_pll",
-			reg_base + 0x10030);
+			reg_base + 0x10030, NULL, 0);
 	vpll = samsung_clk_register_pll36xx("fout_vpll", "mout_vpllsrc",
-			reg_base + 0x10040);
+			reg_base + 0x10040, NULL, 0);
 
 	samsung_clk_register_fixed_rate(exynos5250_fixed_rate_clks,
 			ARRAY_SIZE(exynos5250_fixed_rate_clks));
diff --git a/drivers/clk/samsung/clk-pll.c b/drivers/clk/samsung/clk-pll.c
index 01f17cf..4b3b3f5 100644
--- a/drivers/clk/samsung/clk-pll.c
+++ b/drivers/clk/samsung/clk-pll.c
@@ -16,6 +16,8 @@ 
 struct samsung_clk_pll {
 	struct clk_hw		hw;
 	const void __iomem	*base;
+	const struct samsung_pll_rate_table *rate_table;
+	unsigned int rate_count;
 };
 
 #define to_clk_pll(_hw) container_of(_hw, struct samsung_clk_pll, hw)
@@ -62,7 +64,9 @@  static const struct clk_ops samsung_pll35xx_clk_ops = {
 };
 
 struct clk * __init samsung_clk_register_pll35xx(const char *name,
-			const char *pname, const void __iomem *base)
+			const char *pname, const void __iomem *base,
+			const struct samsung_pll_rate_table *rate_table,
+			const unsigned int rate_count)
 {
 	struct samsung_clk_pll *pll;
 	struct clk *clk;
@@ -82,6 +86,8 @@  struct clk * __init samsung_clk_register_pll35xx(const char *name,
 
 	pll->hw.init = &init;
 	pll->base = base;
+	pll->rate_table = rate_table;
+	pll->rate_count = rate_count;
 
 	clk = clk_register(NULL, &pll->hw);
 	if (IS_ERR(clk)) {
@@ -137,7 +143,9 @@  static const struct clk_ops samsung_pll36xx_clk_ops = {
 };
 
 struct clk * __init samsung_clk_register_pll36xx(const char *name,
-			const char *pname, const void __iomem *base)
+			const char *pname, const void __iomem *base,
+			const struct samsung_pll_rate_table *rate_table,
+			const unsigned int rate_count)
 {
 	struct samsung_clk_pll *pll;
 	struct clk *clk;
@@ -157,6 +165,8 @@  struct clk * __init samsung_clk_register_pll36xx(const char *name,
 
 	pll->hw.init = &init;
 	pll->base = base;
+	pll->rate_table = rate_table;
+	pll->rate_count = rate_count;
 
 	clk = clk_register(NULL, &pll->hw);
 	if (IS_ERR(clk)) {
diff --git a/drivers/clk/samsung/clk-pll.h b/drivers/clk/samsung/clk-pll.h
index 1329522..a7c0f5a 100644
--- a/drivers/clk/samsung/clk-pll.h
+++ b/drivers/clk/samsung/clk-pll.h
@@ -12,6 +12,31 @@ 
 #ifndef __SAMSUNG_CLK_PLL_H
 #define __SAMSUNG_CLK_PLL_H
 
+#define PLL_35XX_RATE(_rate, _m, _p, _s)			\
+	{							\
+		.rate	=	(_rate),				\
+		.mdiv	=	(_m),				\
+		.pdiv	=	(_p),				\
+		.sdiv	=	(_s),				\
+	}
+
+#define PLL_36XX_RATE(_rate, _m, _p, _s, _k)			\
+	{							\
+		.rate	=	(_rate),				\
+		.mdiv	=	(_m),				\
+		.pdiv	=	(_p),				\
+		.sdiv	=	(_s),				\
+		.kdiv	=	(_k),				\
+	}
+
+struct samsung_pll_rate_table {
+	unsigned  int rate;
+	unsigned int pdiv;
+	unsigned int mdiv;
+	unsigned int sdiv;
+	unsigned int kdiv;
+};
+
 enum pll45xx_type {
 	pll_4500,
 	pll_4502,
@@ -25,9 +50,13 @@  enum pll46xx_type {
 };
 
 extern struct clk * __init samsung_clk_register_pll35xx(const char *name,
-			const char *pname, const void __iomem *base);
+			const char *pname, const void __iomem *base,
+			const struct samsung_pll_rate_table *rate_table,
+			const unsigned int rate_count);
 extern struct clk * __init samsung_clk_register_pll36xx(const char *name,
-			const char *pname, const void __iomem *base);
+			const char *pname, const void __iomem *base,
+			const struct samsung_pll_rate_table *rate_table,
+			const unsigned int rate_count);
 extern struct clk * __init samsung_clk_register_pll45xx(const char *name,
 			const char *pname, const void __iomem *con_reg,
 			enum pll45xx_type type);