[PATCH v3 0/5] clk/exynos5420: add clocks for hdmi subsystem

[PATCH v3 0/5] clk/exynos5420: add clocks for hdmi subsystem

[Rahul Sharma]

Add clock changes for hdmi subsystem for exynos5250 SoC. These
include addition of new clocks like mout_hdmi and smmu_tv, associating
ID to clk_hdmiphy and some essential corrections.

V3:
1) Assign new ID to divider clock keeping sclk_pixel gate same.

V2:
1) Rebase to Mike's Tree.
2) Change smmu_tv to smmu_mixer.

This set is based on Mike's clk-next branch at
https://git.linaro.org/gitweb?p=people/mturquette/linux.git

Rahul Sharma (5):
  clk/exynos5420: add sclk_hdmiphy to the list of special clocks
  clk/exynos5420: add gate clock for mixer sysmmu
  clk/exynos5420: fix the order of parents of hdmi mux
  clk/exynos5420: add hdmi mux to change parents in hdmi driver
  clk/exynos5420: assign dout_pixel id to pixel clock divider

 .../devicetree/bindings/clock/exynos5420-clock.txt  |   12 ++++++++++++
 drivers/clk/samsung/clk-exynos5420.c                |   19 +++++++++++++------
 2 files changed, 25 insertions(+), 6 deletions(-)

-- 
1.7.10.4

[PATCH v3 1/5] clk/exynos5420: add sclk_hdmiphy to the list of special clocks

[Rahul Sharma]

Add sclk_hdmiphy to the list of exposed clocks. This is required
by hdmi driver to change the parent of hdmi clock.

Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
---
 Documentation/devicetree/bindings/clock/exynos5420-clock.txt |    1 +
 drivers/clk/samsung/clk-exynos5420.c                         |    4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
index 9bcc4b1..596a368 100644
--- a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
+++ b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
@@ -59,6 +59,7 @@ clock which they consume.
   sclk_pwm		155
   sclk_gscl_wa		156
   sclk_gscl_wb		157
+  sclk_hdmiphy		158
 
    [Peripheral Clock Gates]
 
diff --git a/drivers/clk/samsung/clk-exynos5420.c b/drivers/clk/samsung/clk-exynos5420.c
index e035fd0..a86cadc 100644
--- a/drivers/clk/samsung/clk-exynos5420.c
+++ b/drivers/clk/samsung/clk-exynos5420.c
@@ -120,7 +120,7 @@ enum exynos5420_clks {
 	sclk_i2s2, sclk_pcm1, sclk_pcm2, sclk_spdif, sclk_hdmi, sclk_pixel,
 	sclk_dp1, sclk_mipi1, sclk_fimd1, sclk_maudio0, sclk_maupcm0,
 	sclk_usbd300, sclk_usbd301, sclk_usbphy300, sclk_usbphy301, sclk_unipro,
-	sclk_pwm, sclk_gscl_wa, sclk_gscl_wb,
+	sclk_pwm, sclk_gscl_wa, sclk_gscl_wb, sclk_hdmiphy,
 
 	/* gate clocks */
 	aclk66_peric = 256, uart0, uart1, uart2, uart3, i2c0, i2c1, i2c2, i2c3,
@@ -297,7 +297,7 @@ static struct samsung_fixed_rate_clock exynos5420_fixed_rate_ext_clks[] __initda
 
 /* fixed rate clocks generated inside the soc */
 static struct samsung_fixed_rate_clock exynos5420_fixed_rate_clks[] __initdata = {
-	FRATE(none, "sclk_hdmiphy", NULL, CLK_IS_ROOT, 24000000),
+	FRATE(sclk_hdmiphy, "sclk_hdmiphy", NULL, CLK_IS_ROOT, 24000000),
 	FRATE(none, "sclk_pwi", NULL, CLK_IS_ROOT, 24000000),
 	FRATE(none, "sclk_usbh20", NULL, CLK_IS_ROOT, 48000000),
 	FRATE(none, "mphy_refclk_ixtal24", NULL, CLK_IS_ROOT, 48000000),
-- 
1.7.10.4

[PATCH v3 2/5] clk/exynos5420: add gate clock for mixer sysmmu

[Rahul Sharma]

Adding sysmmu clock for mixer for exynos5420.

Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
---
 Documentation/devicetree/bindings/clock/exynos5420-clock.txt |    1 +
 drivers/clk/samsung/clk-exynos5420.c                         |    3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
index 596a368..5758a69 100644
--- a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
+++ b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
@@ -180,6 +180,7 @@ clock which they consume.
   fimc_lite3		495
   aclk_g3d		500
   g3d			501
+  smmu_mixer		502
 
 Example 1: An example of a clock controller node is listed below.
 
diff --git a/drivers/clk/samsung/clk-exynos5420.c b/drivers/clk/samsung/clk-exynos5420.c
index a86cadc..4e0c13e 100644
--- a/drivers/clk/samsung/clk-exynos5420.c
+++ b/drivers/clk/samsung/clk-exynos5420.c
@@ -138,7 +138,7 @@ enum exynos5420_clks {
 	aclk300_gscl = 460, smmu_gscl0, smmu_gscl1, gscl_wa, gscl_wb, gscl0,
 	gscl1, clk_3aa, aclk266_g2d = 470, sss, slim_sss, mdma0,
 	aclk333_g2d = 480, g2d, aclk333_432_gscl = 490, smmu_3aa, smmu_fimcl0,
-	smmu_fimcl1, smmu_fimcl3, fimc_lite3, aclk_g3d = 500, g3d,
+	smmu_fimcl1, smmu_fimcl3, fimc_lite3, aclk_g3d = 500, g3d, smmu_mixer,
 
 	nr_clks,
 };
@@ -725,6 +725,7 @@ static struct samsung_gate_clock exynos5420_gate_clks[] __initdata = {
 	GATE(smmu_mscl0, "smmu_mscl0", "aclk400_mscl", GATE_IP_MSCL, 8, 0, 0),
 	GATE(smmu_mscl1, "smmu_mscl1", "aclk400_mscl", GATE_IP_MSCL, 9, 0, 0),
 	GATE(smmu_mscl2, "smmu_mscl2", "aclk400_mscl", GATE_IP_MSCL, 10, 0, 0),
+	GATE(smmu_mixer, "smmu_mixer", "aclk200_disp1", GATE_IP_DISP1, 9, 0, 0),
 };
 
 static struct samsung_pll_clock exynos5420_plls[nr_plls] __initdata = {
-- 
1.7.10.4

[PATCH v3 3/5] clk/exynos5420: fix the order of parents of hdmi mux

[Rahul Sharma]

Listing sclk_hdmiphy at 0th position in the list of parents is
causing wrong configuration in reg SRC_DISP10.

Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
---
 drivers/clk/samsung/clk-exynos5420.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/samsung/clk-exynos5420.c b/drivers/clk/samsung/clk-exynos5420.c
index 4e0c13e..522c033 100644
--- a/drivers/clk/samsung/clk-exynos5420.c
+++ b/drivers/clk/samsung/clk-exynos5420.c
@@ -286,7 +286,7 @@ PNAME(audio2_p)	= { "fin_pll", "cdclk2", "sclk_dpll", "sclk_mpll",
 		  "sclk_spll", "sclk_ipll", "sclk_epll", "sclk_rpll" };
 PNAME(spdif_p)	= { "fin_pll", "dout_audio0", "dout_audio1", "dout_audio2",
 		  "spdif_extclk", "sclk_ipll", "sclk_epll", "sclk_rpll" };
-PNAME(hdmi_p)	= { "sclk_hdmiphy", "dout_hdmi_pixel" };
+PNAME(hdmi_p)	= { "dout_hdmi_pixel", "sclk_hdmiphy" };
 PNAME(maudio0_p)	= { "fin_pll", "maudio_clk", "sclk_dpll", "sclk_mpll",
 			  "sclk_spll", "sclk_ipll", "sclk_epll", "sclk_rpll" };
 
-- 
1.7.10.4

[PATCH v3 4/5] clk/exynos5420: add hdmi mux to change parents in hdmi driver

[Rahul Sharma]

hdmi driver needs to change the parent of hdmi clock
to pixel clock or hdmiphy clock, based on the stability
of hdmiphy. This patch is exposing the mux for changing
the parent.

Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
---
 Documentation/devicetree/bindings/clock/exynos5420-clock.txt |    5 +++++
 drivers/clk/samsung/clk-exynos5420.c                         |    5 ++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
index 5758a69..6f16aa8 100644
--- a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
+++ b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
@@ -182,6 +182,11 @@ clock which they consume.
   g3d			501
   smmu_mixer		502
 
+  Mux			ID
+  ----------------------------
+
+  mout_hdmi		1024
+
 Example 1: An example of a clock controller node is listed below.
 
 	clock: clock-controller at 0x10010000 {
diff --git a/drivers/clk/samsung/clk-exynos5420.c b/drivers/clk/samsung/clk-exynos5420.c
index 522c033..5f9bc63 100644
--- a/drivers/clk/samsung/clk-exynos5420.c
+++ b/drivers/clk/samsung/clk-exynos5420.c
@@ -140,6 +140,9 @@ enum exynos5420_clks {
 	aclk333_g2d = 480, g2d, aclk333_432_gscl = 490, smmu_3aa, smmu_fimcl0,
 	smmu_fimcl1, smmu_fimcl3, fimc_lite3, aclk_g3d = 500, g3d, smmu_mixer,
 
+	/* mux clocks */
+	mout_hdmi = 1024,
+
 	nr_clks,
 };
 
@@ -400,7 +403,7 @@ static struct samsung_mux_clock exynos5420_mux_clks[] __initdata = {
 	MUX(none, "mout_mipi1", group2_p, SRC_DISP10, 16, 3),
 	MUX(none, "mout_dp1", group2_p, SRC_DISP10, 20, 3),
 	MUX(none, "mout_pixel", group2_p, SRC_DISP10, 24, 3),
-	MUX(none, "mout_hdmi", hdmi_p, SRC_DISP10, 28, 1),
+	MUX(mout_hdmi, "mout_hdmi", hdmi_p, SRC_DISP10, 28, 1),
 
 	/* MAU Block */
 	MUX(none, "mout_maudio0", maudio0_p, SRC_MAU, 28, 3),
-- 
1.7.10.4

[PATCH v3 4/5] clk/exynos5420: add hdmi mux to change parents in hdmi driver

[Tomasz Figa]

Hi Rahul,

On Monday 26 of August 2013 14:43:02 Rahul Sharma wrote:
> hdmi driver needs to change the parent of hdmi clock
> to pixel clock or hdmiphy clock, based on the stability
> of hdmiphy. This patch is exposing the mux for changing
> the parent.
> 
> Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
> ---
>  Documentation/devicetree/bindings/clock/exynos5420-clock.txt |    5
> +++++ drivers/clk/samsung/clk-exynos5420.c                         |   
> 5 ++++- 2 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git
> a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
> b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt index
> 5758a69..6f16aa8 100644
> --- a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
> +++ b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
> @@ -182,6 +182,11 @@ clock which they consume.
>    g3d			501
>    smmu_mixer		502
> 
> +  Mux			ID
> +  ----------------------------
> +
> +  mout_hdmi		1024

Is there a need for such big hole between smm_mixer and this clock? I 
believe that based on the documentation, the total amount of clocks that 
can be defined may be approximated and some extra margin added, so you 
don't waste so much of numbering space and memory used for lookup array.

Best regards,
Tomasz

[PATCH v3 4/5] clk/exynos5420: add hdmi mux to change parents in hdmi driver

[Rahul Sharma]

On 27 August 2013 05:16, Tomasz Figa <tomasz.figa@gmail.com> wrote:
> Hi Rahul,
>
> On Monday 26 of August 2013 14:43:02 Rahul Sharma wrote:
>> hdmi driver needs to change the parent of hdmi clock
>> to pixel clock or hdmiphy clock, based on the stability
>> of hdmiphy. This patch is exposing the mux for changing
>> the parent.
>>
>> Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
>> ---
>>  Documentation/devicetree/bindings/clock/exynos5420-clock.txt |    5
>> +++++ drivers/clk/samsung/clk-exynos5420.c                         |
>> 5 ++++- 2 files changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git
>> a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
>> b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt index
>> 5758a69..6f16aa8 100644
>> --- a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
>> +++ b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
>> @@ -182,6 +182,11 @@ clock which they consume.
>>    g3d                        501
>>    smmu_mixer         502
>>
>> +  Mux                        ID
>> +  ----------------------------
>> +
>> +  mout_hdmi          1024
>
> Is there a need for such big hole between smm_mixer and this clock? I
> believe that based on the documentation, the total amount of clocks that
> can be defined may be approximated and some extra margin added, so you
> don't waste so much of numbering space and memory used for lookup array.
>

Total number of Gates are coming upto the enum value 540. I can leave gap
of 64 in between for first mux. Similarly, total muxes in system are 118.
Optimum gab would be between 128~150. What you say about these
values?

regards,
Rahul Sharma.

> Best regards,
> Tomasz
>

[PATCH v3 4/5] clk/exynos5420: add hdmi mux to change parents in hdmi driver

[Tomasz Figa]

On Tuesday 27 of August 2013 10:14:01 Rahul Sharma wrote:
> On 27 August 2013 05:16, Tomasz Figa <tomasz.figa@gmail.com> wrote:
> > Hi Rahul,
> > 
> > On Monday 26 of August 2013 14:43:02 Rahul Sharma wrote:
> >> hdmi driver needs to change the parent of hdmi clock
> >> to pixel clock or hdmiphy clock, based on the stability
> >> of hdmiphy. This patch is exposing the mux for changing
> >> the parent.
> >> 
> >> Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
> >> ---
> >> 
> >>  Documentation/devicetree/bindings/clock/exynos5420-clock.txt |    5
> >> 
> >> +++++ drivers/clk/samsung/clk-exynos5420.c                         |
> >> 5 ++++- 2 files changed, 9 insertions(+), 1 deletion(-)
> >> 
> >> diff --git
> >> a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
> >> b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt index
> >> 5758a69..6f16aa8 100644
> >> --- a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
> >> +++ b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
> >> @@ -182,6 +182,11 @@ clock which they consume.
> >> 
> >>    g3d                        501
> >>    smmu_mixer         502
> >> 
> >> +  Mux                        ID
> >> +  ----------------------------
> >> +
> >> +  mout_hdmi          1024
> > 
> > Is there a need for such big hole between smm_mixer and this clock? I
> > believe that based on the documentation, the total amount of clocks
> > that
> > can be defined may be approximated and some extra margin added, so you
> > don't waste so much of numbering space and memory used for lookup
> > array.
> 
> Total number of Gates are coming upto the enum value 540. I can leave gap
> of 64 in between for first mux. Similarly, total muxes in system are
> 118. Optimum gab would be between 128~150. What you say about these
> values?

OK, so let's say that muxes should start at 640 and dividers at 768.

Anyway, ideally, we should break from this idea of grouping and convert 
this way of definition to normal preprocessor macros that could be used 
inside dts files as well. Then we could detach ourselves from referring to 
clocks by numbers, because those macros would do that for us, without the 
need to group clocks together for better readability. See clock driver for 
S3C64xx [1].

This is an idea for further work, though. For now the values I proposed 
should be more than enough.

[1] http://thread.gmane.org/gmane.linux.usb.general/90493/focus=21090

Best regards,
Tomasz

[PATCH v3 4/5] clk/exynos5420: add hdmi mux to change parents in hdmi driver

[Rahul Sharma]

Thanks Tomasz,

I will post the reworked patches with above change.

regards,
Rahul Sharma


On 28 August 2013 17:25, Tomasz Figa <t.figa@samsung.com> wrote:
> On Tuesday 27 of August 2013 10:14:01 Rahul Sharma wrote:
>> On 27 August 2013 05:16, Tomasz Figa <tomasz.figa@gmail.com> wrote:
>> > Hi Rahul,
>> >
>> > On Monday 26 of August 2013 14:43:02 Rahul Sharma wrote:
>> >> hdmi driver needs to change the parent of hdmi clock
>> >> to pixel clock or hdmiphy clock, based on the stability
>> >> of hdmiphy. This patch is exposing the mux for changing
>> >> the parent.
>> >>
>> >> Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
>> >> ---
>> >>
>> >>  Documentation/devicetree/bindings/clock/exynos5420-clock.txt |    5
>> >>
>> >> +++++ drivers/clk/samsung/clk-exynos5420.c                         |
>> >> 5 ++++- 2 files changed, 9 insertions(+), 1 deletion(-)
>> >>
>> >> diff --git
>> >> a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
>> >> b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt index
>> >> 5758a69..6f16aa8 100644
>> >> --- a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
>> >> +++ b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
>> >> @@ -182,6 +182,11 @@ clock which they consume.
>> >>
>> >>    g3d                        501
>> >>    smmu_mixer         502
>> >>
>> >> +  Mux                        ID
>> >> +  ----------------------------
>> >> +
>> >> +  mout_hdmi          1024
>> >
>> > Is there a need for such big hole between smm_mixer and this clock? I
>> > believe that based on the documentation, the total amount of clocks
>> > that
>> > can be defined may be approximated and some extra margin added, so you
>> > don't waste so much of numbering space and memory used for lookup
>> > array.
>>
>> Total number of Gates are coming upto the enum value 540. I can leave gap
>> of 64 in between for first mux. Similarly, total muxes in system are
>> 118. Optimum gab would be between 128~150. What you say about these
>> values?
>
> OK, so let's say that muxes should start at 640 and dividers at 768.
>
> Anyway, ideally, we should break from this idea of grouping and convert
> this way of definition to normal preprocessor macros that could be used
> inside dts files as well. Then we could detach ourselves from referring to
> clocks by numbers, because those macros would do that for us, without the
> need to group clocks together for better readability. See clock driver for
> S3C64xx [1].
>
> This is an idea for further work, though. For now the values I proposed
> should be more than enough.
>
> [1] http://thread.gmane.org/gmane.linux.usb.general/90493/focus=21090
>
> Best regards,
> Tomasz
>

[PATCH v3 5/5] clk/exynos5420: assign dout_pixel id to pixel clock divider

[Rahul Sharma]

dout_pixel is a new ID allocated for pixel clock divider. It is
queried in the driver to pass as the parent to hdmi clock while
switching between parents.

Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
---
 Documentation/devicetree/bindings/clock/exynos5420-clock.txt |    5 +++++
 drivers/clk/samsung/clk-exynos5420.c                         |    5 ++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
index 6f16aa8..4c069bd 100644
--- a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
+++ b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
@@ -187,6 +187,11 @@ clock which they consume.
 
   mout_hdmi		1024
 
+  Divider		ID
+  ----------------------------
+
+  dout_pixel		2048
+
 Example 1: An example of a clock controller node is listed below.
 
 	clock: clock-controller at 0x10010000 {
diff --git a/drivers/clk/samsung/clk-exynos5420.c b/drivers/clk/samsung/clk-exynos5420.c
index 5f9bc63..e55b223 100644
--- a/drivers/clk/samsung/clk-exynos5420.c
+++ b/drivers/clk/samsung/clk-exynos5420.c
@@ -143,6 +143,9 @@ enum exynos5420_clks {
 	/* mux clocks */
 	mout_hdmi = 1024,
 
+	/* divider clocks */
+	dout_pixel = 2048,
+
 	nr_clks,
 };
 
@@ -463,7 +466,7 @@ static struct samsung_div_clock exynos5420_div_clks[] __initdata = {
 	DIV(none, "dout_fimd1", "mout_fimd1", DIV_DISP10, 0, 4),
 	DIV(none, "dout_mipi1", "mout_mipi1", DIV_DISP10, 16, 8),
 	DIV(none, "dout_dp1", "mout_dp1", DIV_DISP10, 24, 4),
-	DIV(none, "dout_hdmi_pixel", "mout_pixel", DIV_DISP10, 28, 4),
+	DIV(dout_pixel, "dout_hdmi_pixel", "mout_pixel", DIV_DISP10, 28, 4),
 
 	/* Audio Block */
 	DIV(none, "dout_maudio0", "mout_maudio0", DIV_MAU, 20, 4),
-- 
1.7.10.4

[PATCH v3 5/5] clk/exynos5420: assign dout_pixel id to pixel clock divider

[Tomasz Figa]

Hi Rahul,

On Monday 26 of August 2013 14:43:03 Rahul Sharma wrote:
> dout_pixel is a new ID allocated for pixel clock divider. It is
> queried in the driver to pass as the parent to hdmi clock while
> switching between parents.
> 
> Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
> ---
>  Documentation/devicetree/bindings/clock/exynos5420-clock.txt |    5
> +++++ drivers/clk/samsung/clk-exynos5420.c                         |   
> 5 ++++- 2 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git
> a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
> b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt index
> 6f16aa8..4c069bd 100644
> --- a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
> +++ b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt
> @@ -187,6 +187,11 @@ clock which they consume.
> 
>    mout_hdmi		1024
> 
> +  Divider		ID
> +  ----------------------------
> +
> +  dout_pixel		2048

That's an even bigger hole.

Could you check in the documentation how many muxes are present in the 
clock controller of Exynos5420, add some margin (presumably rounding up to 
some nice value, not necessarily to a power of two) and calculate a more 
reasonable start value for dividers?

Best regards,
Tomasz'