* Question about fixed-clock
@ 2013-02-18 23:55 Daniel Mack
2013-02-19 0:07 ` Daniel Mack
` (2 more replies)
0 siblings, 3 replies; 13+ messages in thread
From: Daniel Mack @ 2013-02-18 23:55 UTC (permalink / raw)
To: Mike Turquette; +Cc: Russell King, linux-arm-kernel, LKML
Hi,
This might be a stupid question, but I'm somehow stuck here. I'm using a
driver with the following DTS sub-node:
ref25: ref25M {
compatible = "fixed-clock";
#clock-cells = <0>;
clock-frequency = <25000000>;
};
clock-generator@0 {
/* ... */
#clock-cells = <1>;
clocks = <&ref25>;
}
The device driver for clock-generator uses something like the following
call to get its clock:
clk = of_clk_get(np, 0);
but the return value is ERR_PTR(-ENOENT) and I also can't find this
clock in the clk debugfs tree.
This is on a OMAP/AM33xx device with kernel 3.8-rc7 plus the -next tips
of arm-soc and omap, but with no other special clock options selected in
the config. Is there anything I'm missing to correctly instantiate the
dummy clock?
Thanks for a pointer,
Daniel
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: Question about fixed-clock
2013-02-18 23:55 Question about fixed-clock Daniel Mack
@ 2013-02-19 0:07 ` Daniel Mack
2013-02-19 1:33 ` Fabio Estevam
2013-02-19 3:39 ` Afzal Mohammed
2 siblings, 0 replies; 13+ messages in thread
From: Daniel Mack @ 2013-02-19 0:07 UTC (permalink / raw)
To: Mike Turquette; +Cc: Russell King, linux-arm-kernel, LKML
On Tue, Feb 19, 2013 at 12:55 AM, Daniel Mack <zonque@gmail.com> wrote:
> Hi,
>
> This might be a stupid question, but I'm somehow stuck here. I'm using a
> driver with the following DTS sub-node:
>
> ref25: ref25M {
> compatible = "fixed-clock";
> #clock-cells = <0>;
> clock-frequency = <25000000>;
> };
>
> clock-generator@0 {
> /* ... */
> #clock-cells = <1>;
Sorry - this is actually <0>.
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: Question about fixed-clock
2013-02-18 23:55 Question about fixed-clock Daniel Mack
2013-02-19 0:07 ` Daniel Mack
@ 2013-02-19 1:33 ` Fabio Estevam
2013-02-19 9:53 ` Daniel Mack
2013-02-19 3:39 ` Afzal Mohammed
2 siblings, 1 reply; 13+ messages in thread
From: Fabio Estevam @ 2013-02-19 1:33 UTC (permalink / raw)
To: Daniel Mack; +Cc: Mike Turquette, Russell King, LKML, linux-arm-kernel
Hi Daniel,
On Mon, Feb 18, 2013 at 8:55 PM, Daniel Mack <zonque@gmail.com> wrote:
> Hi,
>
> This might be a stupid question, but I'm somehow stuck here. I'm using a
> driver with the following DTS sub-node:
>
> ref25: ref25M {
> compatible = "fixed-clock";
> #clock-cells = <0>;
> clock-frequency = <25000000>;
> };
>
> clock-generator@0 {
> /* ... */
> #clock-cells = <1>;
> clocks = <&ref25>;
> }
>
> The device driver for clock-generator uses something like the following
> call to get its clock:
>
> clk = of_clk_get(np, 0);
>
> but the return value is ERR_PTR(-ENOENT) and I also can't find this
> clock in the clk debugfs tree.
>
> This is on a OMAP/AM33xx device with kernel 3.8-rc7 plus the -next tips
> of arm-soc and omap, but with no other special clock options selected in
> the config. Is there anything I'm missing to correctly instantiate the
> dummy clock?
Have you registered it with clk_register_fixed_rate() ?
In imx we use imx_clk_fixed, which in turns call clk_register_fixed_rate().
Take a look at arch/arm/mach-imx/clk-imx51-imx53.c for a reference.
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: Question about fixed-clock
2013-02-18 23:55 Question about fixed-clock Daniel Mack
2013-02-19 0:07 ` Daniel Mack
2013-02-19 1:33 ` Fabio Estevam
@ 2013-02-19 3:39 ` Afzal Mohammed
2 siblings, 0 replies; 13+ messages in thread
From: Afzal Mohammed @ 2013-02-19 3:39 UTC (permalink / raw)
To: Daniel Mack; +Cc: Mike Turquette, Russell King, LKML, linux-arm-kernel
Hi Daniel,
On Tue, Feb 19, 2013 at 12:55:52AM +0100, Daniel Mack wrote:
> ref25: ref25M {
> compatible = "fixed-clock";
> #clock-cells = <0>;
> clock-frequency = <25000000>;
> };
>
> clock-generator@0 {
> /* ... */
> #clock-cells = <1>;
> clocks = <&ref25>;
> }
>
> The device driver for clock-generator uses something like the following
> call to get its clock:
>
> clk = of_clk_get(np, 0);
>
> but the return value is ERR_PTR(-ENOENT) and I also can't find this
> clock in the clk debugfs tree.
Hope invoking of_clk_init before clock generator driver helps
Regards
Afzal
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: Question about fixed-clock
2013-02-19 1:33 ` Fabio Estevam
@ 2013-02-19 9:53 ` Daniel Mack
[not found] ` <20130219172246.11471.14635@quantum>
2013-03-07 18:42 ` Afzal Mohammed
0 siblings, 2 replies; 13+ messages in thread
From: Daniel Mack @ 2013-02-19 9:53 UTC (permalink / raw)
To: Fabio Estevam
Cc: Mike Turquette, Russell King, LKML, linux-arm-kernel, Afzal Mohammed
Hi Fabio,
Hi Afzal,
On 19.02.2013 02:33, Fabio Estevam wrote:
> On Mon, Feb 18, 2013 at 8:55 PM, Daniel Mack <zonque@gmail.com> wrote:
>> Hi,
>>
>> This might be a stupid question, but I'm somehow stuck here. I'm using a
>> driver with the following DTS sub-node:
>>
>> ref25: ref25M {
>> compatible = "fixed-clock";
>> #clock-cells = <0>;
>> clock-frequency = <25000000>;
>> };
>>
>> clock-generator@0 {
>> /* ... */
>> #clock-cells = <1>;
>> clocks = <&ref25>;
>> }
>>
>> The device driver for clock-generator uses something like the following
>> call to get its clock:
>>
>> clk = of_clk_get(np, 0);
>>
>> but the return value is ERR_PTR(-ENOENT) and I also can't find this
>> clock in the clk debugfs tree.
>>
>> This is on a OMAP/AM33xx device with kernel 3.8-rc7 plus the -next tips
>> of arm-soc and omap, but with no other special clock options selected in
>> the config. Is there anything I'm missing to correctly instantiate the
>> dummy clock?
>
> Have you registered it with clk_register_fixed_rate() ?
>
> In imx we use imx_clk_fixed, which in turns call clk_register_fixed_rate().
>
> Take a look at arch/arm/mach-imx/clk-imx51-imx53.c for a reference.
Hmm no, I didn't do anything else than adding it to the DT in the first
place, hoping that a driver will pick it up and add the clock for me.
But it turns out that of_clk_init() is not called at all on my platform.
I'm doing this now from omap_generic_init() and it works. If that's an
appropriate place to call it, I can provide a patch.
Thanks,
Daniel
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: Question about fixed-clock
[not found] ` <20130219172246.11471.14635@quantum>
@ 2013-02-19 17:32 ` Daniel Mack
2013-03-02 14:09 ` Daniel Mack
0 siblings, 1 reply; 13+ messages in thread
From: Daniel Mack @ 2013-02-19 17:32 UTC (permalink / raw)
To: Mike Turquette
Cc: Fabio Estevam, Russell King, LKML, linux-arm-kernel,
Afzal Mohammed, paul, rnayak
[-- Attachment #1: Type: text/plain, Size: 2562 bytes --]
On 19.02.2013 18:22, Mike Turquette wrote:
> Quoting Daniel Mack (2013-02-19 01:53:18)
>> Hi Fabio,
>> Hi Afzal,
>>
>> On 19.02.2013 02:33, Fabio Estevam wrote:
>>> On Mon, Feb 18, 2013 at 8:55 PM, Daniel Mack <zonque@gmail.com> wrote:
>>>> Hi,
>>>>
>>>> This might be a stupid question, but I'm somehow stuck here. I'm using a
>>>> driver with the following DTS sub-node:
>>>>
>>>> ref25: ref25M {
>>>> compatible = "fixed-clock";
>>>> #clock-cells = <0>;
>>>> clock-frequency = <25000000>;
>>>> };
>>>>
>>>> clock-generator@0 {
>>>> /* ... */
>>>> #clock-cells = <1>;
>>>> clocks = <&ref25>;
>>>> }
>>>>
>>>> The device driver for clock-generator uses something like the following
>>>> call to get its clock:
>>>>
>>>> clk = of_clk_get(np, 0);
>>>>
>>>> but the return value is ERR_PTR(-ENOENT) and I also can't find this
>>>> clock in the clk debugfs tree.
>>>>
>>>> This is on a OMAP/AM33xx device with kernel 3.8-rc7 plus the -next tips
>>>> of arm-soc and omap, but with no other special clock options selected in
>>>> the config. Is there anything I'm missing to correctly instantiate the
>>>> dummy clock?
>>>
>>> Have you registered it with clk_register_fixed_rate() ?
>>>
>>> In imx we use imx_clk_fixed, which in turns call clk_register_fixed_rate().
>>>
>>> Take a look at arch/arm/mach-imx/clk-imx51-imx53.c for a reference.
>>
>> Hmm no, I didn't do anything else than adding it to the DT in the first
>> place, hoping that a driver will pick it up and add the clock for me.
>> But it turns out that of_clk_init() is not called at all on my platform.
>>
>> I'm doing this now from omap_generic_init() and it works. If that's an
>> appropriate place to call it, I can provide a patch.
>>
>
> You can provide a patch, but your example above is for a dummy clock,
> correct?
No, it's a real clock with a fixed frequency on the board, which feeds
another clock chip. I thought this is what fixed-clock is for, just like
what a fixed-regulator does? Or how would you describe such a thing in
DT, in order to use it as input to another device?
> It would be best to post your patch along with a real-world
> use for calling of_clk_init().
Not sure what you mean exactly, but the patch is attached. However, I
still think I lack some understanding here - the fact that compatible
strings have to be passed explicitly from generic code feels wrong.
Thanks,
Daniel
[-- Attachment #2: 0001-ARM-OMAP-generic-add-call-to-of_clk_init.patch --]
[-- Type: text/x-patch, Size: 1336 bytes --]
>From 850120371830ffb5e2146aeb2d21c724d6ded09e Mon Sep 17 00:00:00 2001
From: Daniel Mack <zonque@gmail.com>
Date: Tue, 19 Feb 2013 12:05:25 +0100
Subject: [PATCH] ARM: OMAP: generic: add call to of_clk_init()
This is needed to instanciate fixed clocks in the DT.
Signed-off-by: Daniel Mack <zonque@gmail.com>
---
arch/arm/mach-omap2/board-generic.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/arm/mach-omap2/board-generic.c b/arch/arm/mach-omap2/board-generic.c
index 0274ff7..3580f16 100644
--- a/arch/arm/mach-omap2/board-generic.c
+++ b/arch/arm/mach-omap2/board-generic.c
@@ -15,6 +15,7 @@
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/irqdomain.h>
+#include <linux/clk-provider.h>
#include <asm/mach/arch.h>
@@ -35,6 +36,11 @@ static struct of_device_id omap_dt_match_table[] __initdata = {
{ }
};
+static const __initconst struct of_device_id clk_match[] = {
+ { .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
+ {}
+};
+
static void __init omap_generic_init(void)
{
omap_sdrc_init(NULL, NULL);
@@ -49,6 +55,7 @@ static void __init omap_generic_init(void)
omap4_panda_display_init_of();
else if (of_machine_is_compatible("ti,omap4-sdp"))
omap_4430sdp_display_init_of();
+ of_clk_init(clk_match);
}
#ifdef CONFIG_SOC_OMAP2420
--
1.8.1.2
^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: Question about fixed-clock
2013-02-19 17:32 ` Daniel Mack
@ 2013-03-02 14:09 ` Daniel Mack
0 siblings, 0 replies; 13+ messages in thread
From: Daniel Mack @ 2013-03-02 14:09 UTC (permalink / raw)
To: Mike Turquette
Cc: Fabio Estevam, Russell King, LKML, linux-arm-kernel,
Afzal Mohammed, paul, rnayak
Hi eyerone,
On 19.02.2013 18:32, Daniel Mack wrote:
> On 19.02.2013 18:22, Mike Turquette wrote:
>> > Quoting Daniel Mack (2013-02-19 01:53:18)
>>> >> Hi Fabio,
>>> >> Hi Afzal,
>>> >>
>>> >> On 19.02.2013 02:33, Fabio Estevam wrote:
>>>> >>> On Mon, Feb 18, 2013 at 8:55 PM, Daniel Mack <zonque@gmail.com> wrote:
>>>>> >>>> Hi,
>>>>> >>>>
>>>>> >>>> This might be a stupid question, but I'm somehow stuck here. I'm using a
>>>>> >>>> driver with the following DTS sub-node:
>>>>> >>>>
>>>>> >>>> ref25: ref25M {
>>>>> >>>> compatible = "fixed-clock";
>>>>> >>>> #clock-cells = <0>;
>>>>> >>>> clock-frequency = <25000000>;
>>>>> >>>> };
>>>>> >>>>
>>>>> >>>> clock-generator@0 {
>>>>> >>>> /* ... */
>>>>> >>>> #clock-cells = <1>;
>>>>> >>>> clocks = <&ref25>;
>>>>> >>>> }
>>>>> >>>>
>>>>> >>>> The device driver for clock-generator uses something like the following
>>>>> >>>> call to get its clock:
>>>>> >>>>
>>>>> >>>> clk = of_clk_get(np, 0);
>>>>> >>>>
>>>>> >>>> but the return value is ERR_PTR(-ENOENT) and I also can't find this
>>>>> >>>> clock in the clk debugfs tree.
>>>>> >>>>
>>>>> >>>> This is on a OMAP/AM33xx device with kernel 3.8-rc7 plus the -next tips
>>>>> >>>> of arm-soc and omap, but with no other special clock options selected in
>>>>> >>>> the config. Is there anything I'm missing to correctly instantiate the
>>>>> >>>> dummy clock?
>>>> >>>
>>>> >>> Have you registered it with clk_register_fixed_rate() ?
>>>> >>>
>>>> >>> In imx we use imx_clk_fixed, which in turns call clk_register_fixed_rate().
>>>> >>>
>>>> >>> Take a look at arch/arm/mach-imx/clk-imx51-imx53.c for a reference.
>>> >>
>>> >> Hmm no, I didn't do anything else than adding it to the DT in the first
>>> >> place, hoping that a driver will pick it up and add the clock for me.
>>> >> But it turns out that of_clk_init() is not called at all on my platform.
>>> >>
>>> >> I'm doing this now from omap_generic_init() and it works. If that's an
>>> >> appropriate place to call it, I can provide a patch.
>>> >>
>> >
>> > You can provide a patch, but your example above is for a dummy clock,
>> > correct?
> No, it's a real clock with a fixed frequency on the board, which feeds
> another clock chip. I thought this is what fixed-clock is for, just like
> what a fixed-regulator does? Or how would you describe such a thing in
> DT, in order to use it as input to another device?
>
>> > It would be best to post your patch along with a real-world
>> > use for calling of_clk_init().
> Not sure what you mean exactly, but the patch is attached. However, I
> still think I lack some understanding here - the fact that compatible
> strings have to be passed explicitly from generic code feels wrong.
>
>
> Thanks,
> Daniel
>
>
> 0001-ARM-OMAP-generic-add-call-to-of_clk_init.patch
>
>
> From 850120371830ffb5e2146aeb2d21c724d6ded09e Mon Sep 17 00:00:00 2001
> From: Daniel Mack <zonque@gmail.com>
> Date: Tue, 19 Feb 2013 12:05:25 +0100
> Subject: [PATCH] ARM: OMAP: generic: add call to of_clk_init()
>
> This is needed to instanciate fixed clocks in the DT.
>
> Signed-off-by: Daniel Mack <zonque@gmail.com>
> ---
> arch/arm/mach-omap2/board-generic.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/arch/arm/mach-omap2/board-generic.c b/arch/arm/mach-omap2/board-generic.c
> index 0274ff7..3580f16 100644
> --- a/arch/arm/mach-omap2/board-generic.c
> +++ b/arch/arm/mach-omap2/board-generic.c
> @@ -15,6 +15,7 @@
> #include <linux/of_irq.h>
> #include <linux/of_platform.h>
> #include <linux/irqdomain.h>
> +#include <linux/clk-provider.h>
>
> #include <asm/mach/arch.h>
>
> @@ -35,6 +36,11 @@ static struct of_device_id omap_dt_match_table[] __initdata = {
> { }
> };
>
> +static const __initconst struct of_device_id clk_match[] = {
> + { .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
> + {}
> +};
> +
> static void __init omap_generic_init(void)
> {
> omap_sdrc_init(NULL, NULL);
> @@ -49,6 +55,7 @@ static void __init omap_generic_init(void)
> omap4_panda_display_init_of();
> else if (of_machine_is_compatible("ti,omap4-sdp"))
> omap_4430sdp_display_init_of();
> + of_clk_init(clk_match);
> }
>
> #ifdef CONFIG_SOC_OMAP2420
Any opinion about this approach?
Thanks,
Daniel
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: Question about fixed-clock
2013-02-19 9:53 ` Daniel Mack
[not found] ` <20130219172246.11471.14635@quantum>
@ 2013-03-07 18:42 ` Afzal Mohammed
2013-03-07 22:31 ` Daniel Mack
1 sibling, 1 reply; 13+ messages in thread
From: Afzal Mohammed @ 2013-03-07 18:42 UTC (permalink / raw)
To: Daniel Mack
Cc: Fabio Estevam, Russell King, Mike Turquette, LKML, linux-arm-kernel
Hi Daniel,
On Tue, Feb 19, 2013 at 09:09:31AM +0530, Afzal Mohammed wrote:
> Hope invoking of_clk_init before clock generator driver helps
Mails coming from this id are in my personal capacity.
On Tue, Feb 19, 2013 at 10:53:18AM +0100, Daniel Mack wrote:
> On 19.02.2013 02:33, Fabio Estevam wrote:
> > Have you registered it with clk_register_fixed_rate() ?
> Hmm no, I didn't do anything else than adding it to the DT in the first
> place, hoping that a driver will pick it up and add the clock for me.
> But it turns out that of_clk_init() is not called at all on my platform.
>
> I'm doing this now from omap_generic_init() and it works. If that's an
> appropriate place to call it, I can provide a patch.
Initially didn't realize that it was for an am335x based one.
I feel that for a platform having it's clock tree in DT, of_clk_init
would take care of it, but if clock tree data is not in DT, clock
tree would have to be extended in a non-DT way.
Regards
Afzal
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: Question about fixed-clock
2013-03-07 18:42 ` Afzal Mohammed
@ 2013-03-07 22:31 ` Daniel Mack
2013-03-08 2:15 ` Mark Brown
0 siblings, 1 reply; 13+ messages in thread
From: Daniel Mack @ 2013-03-07 22:31 UTC (permalink / raw)
To: Afzal Mohammed
Cc: Fabio Estevam, Russell King, Mike Turquette, LKML, Grant Likely,
Mark Brown, Rob Herring
Hi Afzal,
thanks for looking into this.
On 07.03.2013 19:42, Afzal Mohammed wrote:
> On Tue, Feb 19, 2013 at 09:09:31AM +0530, Afzal Mohammed wrote:
>
>> Hope invoking of_clk_init before clock generator driver helps
>
> Mails coming from this id are in my personal capacity.
>
> On Tue, Feb 19, 2013 at 10:53:18AM +0100, Daniel Mack wrote:
>> On 19.02.2013 02:33, Fabio Estevam wrote:
>
>>> Have you registered it with clk_register_fixed_rate() ?
>
>> Hmm no, I didn't do anything else than adding it to the DT in the first
>> place, hoping that a driver will pick it up and add the clock for me.
>> But it turns out that of_clk_init() is not called at all on my platform.
>>
>> I'm doing this now from omap_generic_init() and it works. If that's an
>> appropriate place to call it, I can provide a patch.
>
> Initially didn't realize that it was for an am335x based one.
>
> I feel that for a platform having it's clock tree in DT, of_clk_init
> would take care of it, but if clock tree data is not in DT, clock
> tree would have to be extended in a non-DT way.
Hmm, I don't follow. So for generic OMAP board in general which does
*not* have its SoC clocks in DT, the question is who's in charge of
registering out-of-SoC fixed clocks that are defined in DT.
Note that the clock I'm dealing with here is _outside_ of the SoC, and I
just need to have it in DT, so it can feed another clock chip's input pin.
Grep'ing through arch/arm, it seems that the imx arch does the same
thing my patch does, but I could also imagine that it should be done
somewhere from the DT core. I copied Grant, Rob and Mark for more comments.
Thanks,
Daniel
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: Question about fixed-clock
2013-03-07 22:31 ` Daniel Mack
@ 2013-03-08 2:15 ` Mark Brown
2013-03-08 13:30 ` Daniel Mack
0 siblings, 1 reply; 13+ messages in thread
From: Mark Brown @ 2013-03-08 2:15 UTC (permalink / raw)
To: Daniel Mack
Cc: Afzal Mohammed, Fabio Estevam, Russell King, Mike Turquette,
LKML, Grant Likely, Rob Herring
[-- Attachment #1: Type: text/plain, Size: 967 bytes --]
On Thu, Mar 07, 2013 at 11:31:59PM +0100, Daniel Mack wrote:
> On 07.03.2013 19:42, Afzal Mohammed wrote:
> > I feel that for a platform having it's clock tree in DT, of_clk_init
> > would take care of it, but if clock tree data is not in DT, clock
> > tree would have to be extended in a non-DT way.
> Hmm, I don't follow. So for generic OMAP board in general which does
> *not* have its SoC clocks in DT, the question is who's in charge of
> registering out-of-SoC fixed clocks that are defined in DT.
> Note that the clock I'm dealing with here is _outside_ of the SoC, and I
> just need to have it in DT, so it can feed another clock chip's input pin.
> Grep'ing through arch/arm, it seems that the imx arch does the same
> thing my patch does, but I could also imagine that it should be done
> somewhere from the DT core. I copied Grant, Rob and Mark for more comments.
Wouldn't this just be set up by the DT in the same way that other
off-SoC hardware is?
[-- Attachment #2: Digital signature --]
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^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: Question about fixed-clock
2013-03-08 2:15 ` Mark Brown
@ 2013-03-08 13:30 ` Daniel Mack
2013-03-09 8:26 ` Sebastian Hesselbarth
2013-03-12 18:40 ` Mark Brown
0 siblings, 2 replies; 13+ messages in thread
From: Daniel Mack @ 2013-03-08 13:30 UTC (permalink / raw)
To: Mark Brown
Cc: Afzal Mohammed, Fabio Estevam, Russell King, Mike Turquette,
LKML, Grant Likely, Rob Herring, Sebastian Hesselbarth,
Fabio Estevam
On 08.03.2013 03:15, Mark Brown wrote:
> On Thu, Mar 07, 2013 at 11:31:59PM +0100, Daniel Mack wrote:
>> On 07.03.2013 19:42, Afzal Mohammed wrote:
>
>>> I feel that for a platform having it's clock tree in DT, of_clk_init
>>> would take care of it, but if clock tree data is not in DT, clock
>>> tree would have to be extended in a non-DT way.
>
>> Hmm, I don't follow. So for generic OMAP board in general which does
>> *not* have its SoC clocks in DT, the question is who's in charge of
>> registering out-of-SoC fixed clocks that are defined in DT.
>
>> Note that the clock I'm dealing with here is _outside_ of the SoC, and I
>> just need to have it in DT, so it can feed another clock chip's input pin.
>
>> Grep'ing through arch/arm, it seems that the imx arch does the same
>> thing my patch does, but I could also imagine that it should be done
>> somewhere from the DT core. I copied Grant, Rob and Mark for more comments.
>
> Wouldn't this just be set up by the DT in the same way that other
> off-SoC hardware is?
Well, I thought so too. To repeat, in my DT, I have:
ref25: ref25M {
compatible = "fixed-clock";
#clock-cells = <0>;
clock-frequency = <25000000>;
};
to represent an osciallator on the board. I need to specify it here so I
can pass a reference to another chip:
si5351a: clock-generator@60 {
compatible = "silabs,si5351a";
clocks = <&ref25>;
};
I would have expected that "fixed-clock" is matched by a driver lurking
around for DT boards, just like what the "fixed-regulator" driver does
for instance. But the clock device isn't initialized unless board code
explicitly calls of_clk_init() with a table mentioning "fixed-clock", as
in my patch.
I don't know the clock framework well enough, but it seems that either
all DT boards are supposed to do the same in their generic bits (which
sounds like a lot of code duplication), or the fixed-clock driver should
behave like any other driver wrt its probing from DT. I'm open to
suggestions :)
Daniel
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: Question about fixed-clock
2013-03-08 13:30 ` Daniel Mack
@ 2013-03-09 8:26 ` Sebastian Hesselbarth
2013-03-12 18:40 ` Mark Brown
1 sibling, 0 replies; 13+ messages in thread
From: Sebastian Hesselbarth @ 2013-03-09 8:26 UTC (permalink / raw)
To: Daniel Mack
Cc: Mark Brown, Afzal Mohammed, Fabio Estevam, Russell King,
Mike Turquette, LKML, Grant Likely, Rob Herring
On 03/08/2013 02:30 PM, Daniel Mack wrote:
> On 08.03.2013 03:15, Mark Brown wrote:
>> On Thu, Mar 07, 2013 at 11:31:59PM +0100, Daniel Mack wrote:
>>> On 07.03.2013 19:42, Afzal Mohammed wrote:
>>> Grep'ing through arch/arm, it seems that the imx arch does the same
>>> thing my patch does, but I could also imagine that it should be done
>>> somewhere from the DT core. I copied Grant, Rob and Mark for more comments.
>>
>> Wouldn't this just be set up by the DT in the same way that other
>> off-SoC hardware is?
>
> [...]
>
> I don't know the clock framework well enough, but it seems that either
> all DT boards are supposed to do the same in their generic bits (which
> sounds like a lot of code duplication), or the fixed-clock driver should
> behave like any other driver wrt its probing from DT. I'm open to
> suggestions :)
Daniel,
the current common clock framework does not register any of its "core"
clocks, i.e. fixed-clock, et.al. I haven't had a look at the way regulator
api registers them. But if you find the way reasonable, why not propose
a patch for ccf that registers at least a set of the core clocks itself?
Sebastian
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: Question about fixed-clock
2013-03-08 13:30 ` Daniel Mack
2013-03-09 8:26 ` Sebastian Hesselbarth
@ 2013-03-12 18:40 ` Mark Brown
1 sibling, 0 replies; 13+ messages in thread
From: Mark Brown @ 2013-03-12 18:40 UTC (permalink / raw)
To: Daniel Mack
Cc: Afzal Mohammed, Fabio Estevam, Russell King, Mike Turquette,
LKML, Grant Likely, Rob Herring, Sebastian Hesselbarth
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On Fri, Mar 08, 2013 at 02:30:27PM +0100, Daniel Mack wrote:
> On 08.03.2013 03:15, Mark Brown wrote:
> > Wouldn't this just be set up by the DT in the same way that other
> > off-SoC hardware is?
> Well, I thought so too. To repeat, in my DT, I have:
OK, I got CCed in part way through the thread.
> I would have expected that "fixed-clock" is matched by a driver lurking
> around for DT boards, just like what the "fixed-regulator" driver does
> for instance. But the clock device isn't initialized unless board code
> explicitly calls of_clk_init() with a table mentioning "fixed-clock", as
> in my patch.
> I don't know the clock framework well enough, but it seems that either
> all DT boards are supposed to do the same in their generic bits (which
> sounds like a lot of code duplication), or the fixed-clock driver should
> behave like any other driver wrt its probing from DT. I'm open to
> suggestions :)
Your expectation sounds like what I'd expect too...
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^ permalink raw reply [flat|nested] 13+ messages in thread
end of thread, other threads:[~2013-03-12 18:40 UTC | newest]
Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-02-18 23:55 Question about fixed-clock Daniel Mack
2013-02-19 0:07 ` Daniel Mack
2013-02-19 1:33 ` Fabio Estevam
2013-02-19 9:53 ` Daniel Mack
[not found] ` <20130219172246.11471.14635@quantum>
2013-02-19 17:32 ` Daniel Mack
2013-03-02 14:09 ` Daniel Mack
2013-03-07 18:42 ` Afzal Mohammed
2013-03-07 22:31 ` Daniel Mack
2013-03-08 2:15 ` Mark Brown
2013-03-08 13:30 ` Daniel Mack
2013-03-09 8:26 ` Sebastian Hesselbarth
2013-03-12 18:40 ` Mark Brown
2013-02-19 3:39 ` Afzal Mohammed
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