diff mbox

[RFC,2/4] ARM: dts: Add ctrl-core DT node for DRA7

Message ID 1397654063-8055-2-git-send-email-archit@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

archit taneja April 16, 2014, 1:14 p.m. UTC
Add DT node for the ctrl-core sub module of the DRA7 control module. We map the
CTRL_MODULE_CORE address region up to 0x4a002d60, this region contains register
fields which configure clocks. The remainder of the registers are related to
pad configurations or cross-bar configurations, and therefore aren't mapped.

Signed-off-by: Archit Taneja <archit@ti.com>
---
 arch/arm/boot/dts/dra7.dtsi | 13 +++++++++++++
 1 file changed, 13 insertions(+)

Comments

Tony Lindgren April 18, 2014, 5:18 p.m. UTC | #1
* Archit Taneja <archit@ti.com> [140416 06:20]:
> Add DT node for the ctrl-core sub module of the DRA7 control module. We map the
> CTRL_MODULE_CORE address region up to 0x4a002d60, this region contains register
> fields which configure clocks. The remainder of the registers are related to
> pad configurations or cross-bar configurations, and therefore aren't mapped.

Can you please check if this can just use the existing
regmap syscon mapping:

syscon = <&dra7_ctrl_general>;

See how the drivers/regulator/pbias-regulator.c is using the
syscon to initialize a regulator and then omap_hsmmc.c just does
the standard regulator calls.

Depending what the range 0x4a002000 0x6d0 contains, you may
want to set it up as another syscon area.

Regards,

Tony

 
> Signed-off-by: Archit Taneja <archit@ti.com>
> ---
>  arch/arm/boot/dts/dra7.dtsi | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi
> index 1c0f8e1..58bbdf3 100644
> --- a/arch/arm/boot/dts/dra7.dtsi
> +++ b/arch/arm/boot/dts/dra7.dtsi
> @@ -148,6 +148,19 @@
>  			};
>  		};
>  
> +		ctrl_core: ctrl_core@4a002000 {
> +			compatible = "ti,dra7-ctrl-core";
> +			reg = <0x4a002000 0x6d0>;
> +
> +			ctrl_core_clocks: clocks {
> +				#address-cells = <1>;
> +				#size-cells = <0>;
> +			};
> +
> +			ctrl_core_clockdomains: clockdomains {
> +			};
> +		};
> +
>  		counter32k: counter@4ae04000 {
>  			compatible = "ti,omap-counter32k";
>  			reg = <0x4ae04000 0x40>;
> -- 
> 1.8.3.2
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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archit taneja April 21, 2014, 5:15 a.m. UTC | #2
Hi,

On Friday 18 April 2014 10:48 PM, Tony Lindgren wrote:
> * Archit Taneja <archit@ti.com> [140416 06:20]:
>> Add DT node for the ctrl-core sub module of the DRA7 control module. We map the
>> CTRL_MODULE_CORE address region up to 0x4a002d60, this region contains register
>> fields which configure clocks. The remainder of the registers are related to
>> pad configurations or cross-bar configurations, and therefore aren't mapped.
>
> Can you please check if this can just use the existing
> regmap syscon mapping:
>
> syscon = <&dra7_ctrl_general>;
>
> See how the drivers/regulator/pbias-regulator.c is using the
> syscon to initialize a regulator and then omap_hsmmc.c just does
> the standard regulator calls.

The thing is that this bit needs to be set before the the DSS hwmods are 
reset, and that happens very early. If we don't do this, DSS won't reset 
properly, and not get back to an idle state.

I am not sure where I can configure the syscon register early enough 
that it happens before the hwmods are reset. With a syscon mapping, I 
guess we would access the register when the DSS driver is probed. But 
that's too late for us.

Ideally, it would be much better to have a syscon mapping. Do you have 
any suggestions how this can be achieved very early in boot?

Archit

>
> Depending what the range 0x4a002000 0x6d0 contains, you may
> want to set it up as another syscon area.
>
> Regards,
>
> Tony

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Tony Lindgren April 21, 2014, 3:10 p.m. UTC | #3
* Archit Taneja <archit@ti.com> [140420 22:16]:
> Hi,
> 
> On Friday 18 April 2014 10:48 PM, Tony Lindgren wrote:
> >* Archit Taneja <archit@ti.com> [140416 06:20]:
> >>Add DT node for the ctrl-core sub module of the DRA7 control module. We map the
> >>CTRL_MODULE_CORE address region up to 0x4a002d60, this region contains register
> >>fields which configure clocks. The remainder of the registers are related to
> >>pad configurations or cross-bar configurations, and therefore aren't mapped.
> >
> >Can you please check if this can just use the existing
> >regmap syscon mapping:
> >
> >syscon = <&dra7_ctrl_general>;
> >
> >See how the drivers/regulator/pbias-regulator.c is using the
> >syscon to initialize a regulator and then omap_hsmmc.c just does
> >the standard regulator calls.
> 
> The thing is that this bit needs to be set before the the DSS hwmods are
> reset, and that happens very early. If we don't do this, DSS won't reset
> properly, and not get back to an idle state.
> 
> I am not sure where I can configure the syscon register early enough that it
> happens before the hwmods are reset. With a syscon mapping, I guess we would
> access the register when the DSS driver is probed. But that's too late for
> us.
> 
> Ideally, it would be much better to have a syscon mapping. Do you have any
> suggestions how this can be achieved very early in boot?

It's best to move the reset and initialization of DSS happen later. I believe
we already are resetting only some of the hwmods early on.

Regards,

Tony
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archit taneja May 6, 2014, 5:22 a.m. UTC | #4
Hi,

On Monday 21 April 2014 08:40 PM, Tony Lindgren wrote:
> * Archit Taneja <archit@ti.com> [140420 22:16]:
>> Hi,
>>
>> On Friday 18 April 2014 10:48 PM, Tony Lindgren wrote:
>>> * Archit Taneja <archit@ti.com> [140416 06:20]:
>>>> Add DT node for the ctrl-core sub module of the DRA7 control module. We map the
>>>> CTRL_MODULE_CORE address region up to 0x4a002d60, this region contains register
>>>> fields which configure clocks. The remainder of the registers are related to
>>>> pad configurations or cross-bar configurations, and therefore aren't mapped.
>>>
>>> Can you please check if this can just use the existing
>>> regmap syscon mapping:
>>>
>>> syscon = <&dra7_ctrl_general>;
>>>
>>> See how the drivers/regulator/pbias-regulator.c is using the
>>> syscon to initialize a regulator and then omap_hsmmc.c just does
>>> the standard regulator calls.
>>
>> The thing is that this bit needs to be set before the the DSS hwmods are
>> reset, and that happens very early. If we don't do this, DSS won't reset
>> properly, and not get back to an idle state.
>>
>> I am not sure where I can configure the syscon register early enough that it
>> happens before the hwmods are reset. With a syscon mapping, I guess we would
>> access the register when the DSS driver is probed. But that's too late for
>> us.
>>
>> Ideally, it would be much better to have a syscon mapping. Do you have any
>> suggestions how this can be achieved very early in boot?
>
> It's best to move the reset and initialization of DSS happen later. I believe
> we already are resetting only some of the hwmods early on.
>

I looked at this in some more detail. With the current hwmod 
flags(HWMOD_INIT_NO_RESET/NO_IDLE), we still try to enable the IP, it's 
just the reset part(ocp reset/custom reset and sysc register) or the 
disable part that is skipped. hwmod still tries to enable the IP.

This again results in the same issue.

One thing which wasn't clear was that why do we enable a hwmod in the 
first place, if we know that we are going to skip reset?

Archit


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Tony Lindgren May 6, 2014, 2:26 p.m. UTC | #5
* Archit Taneja <archit@ti.com> [140505 22:24]:
> Hi,
> 
> On Monday 21 April 2014 08:40 PM, Tony Lindgren wrote:
> >* Archit Taneja <archit@ti.com> [140420 22:16]:
> >>Hi,
> >>
> >>On Friday 18 April 2014 10:48 PM, Tony Lindgren wrote:
> >>>* Archit Taneja <archit@ti.com> [140416 06:20]:
> >>>>Add DT node for the ctrl-core sub module of the DRA7 control module. We map the
> >>>>CTRL_MODULE_CORE address region up to 0x4a002d60, this region contains register
> >>>>fields which configure clocks. The remainder of the registers are related to
> >>>>pad configurations or cross-bar configurations, and therefore aren't mapped.
> >>>
> >>>Can you please check if this can just use the existing
> >>>regmap syscon mapping:
> >>>
> >>>syscon = <&dra7_ctrl_general>;
> >>>
> >>>See how the drivers/regulator/pbias-regulator.c is using the
> >>>syscon to initialize a regulator and then omap_hsmmc.c just does
> >>>the standard regulator calls.
> >>
> >>The thing is that this bit needs to be set before the the DSS hwmods are
> >>reset, and that happens very early. If we don't do this, DSS won't reset
> >>properly, and not get back to an idle state.
> >>
> >>I am not sure where I can configure the syscon register early enough that it
> >>happens before the hwmods are reset. With a syscon mapping, I guess we would
> >>access the register when the DSS driver is probed. But that's too late for
> >>us.
> >>
> >>Ideally, it would be much better to have a syscon mapping. Do you have any
> >>suggestions how this can be achieved very early in boot?
> >
> >It's best to move the reset and initialization of DSS happen later. I believe
> >we already are resetting only some of the hwmods early on.
> >
> 
> I looked at this in some more detail. With the current hwmod
> flags(HWMOD_INIT_NO_RESET/NO_IDLE), we still try to enable the IP, it's just
> the reset part(ocp reset/custom reset and sysc register) or the disable part
> that is skipped. hwmod still tries to enable the IP.
> 
> This again results in the same issue.
> 
> One thing which wasn't clear was that why do we enable a hwmod in the first
> place, if we know that we are going to skip reset?

Probably to configure the idle bits. In general, we should configure the
modules lazily as the driver probes as requested, and then idle the
unused modules with a late_initcall.

Regards,

Tony
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archit taneja May 8, 2014, 6:02 a.m. UTC | #6
On Tuesday 06 May 2014 07:56 PM, Tony Lindgren wrote:
> * Archit Taneja <archit@ti.com> [140505 22:24]:
>> Hi,
>>
>> On Monday 21 April 2014 08:40 PM, Tony Lindgren wrote:
>>> * Archit Taneja <archit@ti.com> [140420 22:16]:
>>>> Hi,
>>>>
>>>> On Friday 18 April 2014 10:48 PM, Tony Lindgren wrote:
>>>>> * Archit Taneja <archit@ti.com> [140416 06:20]:
>>>>>> Add DT node for the ctrl-core sub module of the DRA7 control module. We map the
>>>>>> CTRL_MODULE_CORE address region up to 0x4a002d60, this region contains register
>>>>>> fields which configure clocks. The remainder of the registers are related to
>>>>>> pad configurations or cross-bar configurations, and therefore aren't mapped.
>>>>>
>>>>> Can you please check if this can just use the existing
>>>>> regmap syscon mapping:
>>>>>
>>>>> syscon = <&dra7_ctrl_general>;
>>>>>
>>>>> See how the drivers/regulator/pbias-regulator.c is using the
>>>>> syscon to initialize a regulator and then omap_hsmmc.c just does
>>>>> the standard regulator calls.
>>>>
>>>> The thing is that this bit needs to be set before the the DSS hwmods are
>>>> reset, and that happens very early. If we don't do this, DSS won't reset
>>>> properly, and not get back to an idle state.
>>>>
>>>> I am not sure where I can configure the syscon register early enough that it
>>>> happens before the hwmods are reset. With a syscon mapping, I guess we would
>>>> access the register when the DSS driver is probed. But that's too late for
>>>> us.
>>>>
>>>> Ideally, it would be much better to have a syscon mapping. Do you have any
>>>> suggestions how this can be achieved very early in boot?
>>>
>>> It's best to move the reset and initialization of DSS happen later. I believe
>>> we already are resetting only some of the hwmods early on.
>>>
>>
>> I looked at this in some more detail. With the current hwmod
>> flags(HWMOD_INIT_NO_RESET/NO_IDLE), we still try to enable the IP, it's just
>> the reset part(ocp reset/custom reset and sysc register) or the disable part
>> that is skipped. hwmod still tries to enable the IP.
>>
>> This again results in the same issue.
>>
>> One thing which wasn't clear was that why do we enable a hwmod in the first
>> place, if we know that we are going to skip reset?
>
> Probably to configure the idle bits. In general, we should configure the
> modules lazily as the driver probes as requested, and then idle the
> unused modules with a late_initcall.

Okay, we were thinking of changing the hwmod code to skip enable for 
hwmods(which have the HWMOD_INIT_NO_RESET flag) altogether. But that 
doesn't seem like a viable option.

I can't think of any other way of getting around this, besides making 
control module a clock provider.

Paul said that it's not that bad to make DRA7 CTRL module a clock 
provider, but outside of PRCM code. I guess that would involve having 
something along the lines of of_prcm_init() in mach-omap2/control.c

Archit


Archit

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Tero Kristo May 8, 2014, 7:53 a.m. UTC | #7
On 05/08/2014 09:02 AM, Archit Taneja wrote:
> On Tuesday 06 May 2014 07:56 PM, Tony Lindgren wrote:
>> * Archit Taneja <archit@ti.com> [140505 22:24]:
>>> Hi,
>>>
>>> On Monday 21 April 2014 08:40 PM, Tony Lindgren wrote:
>>>> * Archit Taneja <archit@ti.com> [140420 22:16]:
>>>>> Hi,
>>>>>
>>>>> On Friday 18 April 2014 10:48 PM, Tony Lindgren wrote:
>>>>>> * Archit Taneja <archit@ti.com> [140416 06:20]:
>>>>>>> Add DT node for the ctrl-core sub module of the DRA7 control
>>>>>>> module. We map the
>>>>>>> CTRL_MODULE_CORE address region up to 0x4a002d60, this region
>>>>>>> contains register
>>>>>>> fields which configure clocks. The remainder of the registers are
>>>>>>> related to
>>>>>>> pad configurations or cross-bar configurations, and therefore
>>>>>>> aren't mapped.
>>>>>>
>>>>>> Can you please check if this can just use the existing
>>>>>> regmap syscon mapping:
>>>>>>
>>>>>> syscon = <&dra7_ctrl_general>;
>>>>>>
>>>>>> See how the drivers/regulator/pbias-regulator.c is using the
>>>>>> syscon to initialize a regulator and then omap_hsmmc.c just does
>>>>>> the standard regulator calls.
>>>>>
>>>>> The thing is that this bit needs to be set before the the DSS
>>>>> hwmods are
>>>>> reset, and that happens very early. If we don't do this, DSS won't
>>>>> reset
>>>>> properly, and not get back to an idle state.
>>>>>
>>>>> I am not sure where I can configure the syscon register early
>>>>> enough that it
>>>>> happens before the hwmods are reset. With a syscon mapping, I guess
>>>>> we would
>>>>> access the register when the DSS driver is probed. But that's too
>>>>> late for
>>>>> us.
>>>>>
>>>>> Ideally, it would be much better to have a syscon mapping. Do you
>>>>> have any
>>>>> suggestions how this can be achieved very early in boot?
>>>>
>>>> It's best to move the reset and initialization of DSS happen later.
>>>> I believe
>>>> we already are resetting only some of the hwmods early on.
>>>>
>>>
>>> I looked at this in some more detail. With the current hwmod
>>> flags(HWMOD_INIT_NO_RESET/NO_IDLE), we still try to enable the IP,
>>> it's just
>>> the reset part(ocp reset/custom reset and sysc register) or the
>>> disable part
>>> that is skipped. hwmod still tries to enable the IP.
>>>
>>> This again results in the same issue.
>>>
>>> One thing which wasn't clear was that why do we enable a hwmod in the
>>> first
>>> place, if we know that we are going to skip reset?
>>
>> Probably to configure the idle bits. In general, we should configure the
>> modules lazily as the driver probes as requested, and then idle the
>> unused modules with a late_initcall.
>
> Okay, we were thinking of changing the hwmod code to skip enable for
> hwmods(which have the HWMOD_INIT_NO_RESET flag) altogether. But that
> doesn't seem like a viable option.
>
> I can't think of any other way of getting around this, besides making
> control module a clock provider.
>
> Paul said that it's not that bad to make DRA7 CTRL module a clock
> provider, but outside of PRCM code. I guess that would involve having
> something along the lines of of_prcm_init() in mach-omap2/control.c

That sounds like pretty much one of the things I have done here:

https://github.com/t-kristo/linux-pm/tree/3.14-rc4-cm-prm-driver-wip

The patches in their current form haven't been posted yet though, as 
they are waiting for some of the pre-reqs, but feel free to re-use 
something from here.

-Tero

>
> Archit
>
>
> Archit
>

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archit taneja May 8, 2014, 8:16 a.m. UTC | #8
On Thursday 08 May 2014 01:23 PM, Tero Kristo wrote:
> On 05/08/2014 09:02 AM, Archit Taneja wrote:
>> On Tuesday 06 May 2014 07:56 PM, Tony Lindgren wrote:
>>> * Archit Taneja <archit@ti.com> [140505 22:24]:
>>>> Hi,
>>>>
>>>> On Monday 21 April 2014 08:40 PM, Tony Lindgren wrote:
>>>>> * Archit Taneja <archit@ti.com> [140420 22:16]:
>>>>>> Hi,
>>>>>>
>>>>>> On Friday 18 April 2014 10:48 PM, Tony Lindgren wrote:
>>>>>>> * Archit Taneja <archit@ti.com> [140416 06:20]:
>>>>>>>> Add DT node for the ctrl-core sub module of the DRA7 control
>>>>>>>> module. We map the
>>>>>>>> CTRL_MODULE_CORE address region up to 0x4a002d60, this region
>>>>>>>> contains register
>>>>>>>> fields which configure clocks. The remainder of the registers are
>>>>>>>> related to
>>>>>>>> pad configurations or cross-bar configurations, and therefore
>>>>>>>> aren't mapped.
>>>>>>>
>>>>>>> Can you please check if this can just use the existing
>>>>>>> regmap syscon mapping:
>>>>>>>
>>>>>>> syscon = <&dra7_ctrl_general>;
>>>>>>>
>>>>>>> See how the drivers/regulator/pbias-regulator.c is using the
>>>>>>> syscon to initialize a regulator and then omap_hsmmc.c just does
>>>>>>> the standard regulator calls.
>>>>>>
>>>>>> The thing is that this bit needs to be set before the the DSS
>>>>>> hwmods are
>>>>>> reset, and that happens very early. If we don't do this, DSS won't
>>>>>> reset
>>>>>> properly, and not get back to an idle state.
>>>>>>
>>>>>> I am not sure where I can configure the syscon register early
>>>>>> enough that it
>>>>>> happens before the hwmods are reset. With a syscon mapping, I guess
>>>>>> we would
>>>>>> access the register when the DSS driver is probed. But that's too
>>>>>> late for
>>>>>> us.
>>>>>>
>>>>>> Ideally, it would be much better to have a syscon mapping. Do you
>>>>>> have any
>>>>>> suggestions how this can be achieved very early in boot?
>>>>>
>>>>> It's best to move the reset and initialization of DSS happen later.
>>>>> I believe
>>>>> we already are resetting only some of the hwmods early on.
>>>>>
>>>>
>>>> I looked at this in some more detail. With the current hwmod
>>>> flags(HWMOD_INIT_NO_RESET/NO_IDLE), we still try to enable the IP,
>>>> it's just
>>>> the reset part(ocp reset/custom reset and sysc register) or the
>>>> disable part
>>>> that is skipped. hwmod still tries to enable the IP.
>>>>
>>>> This again results in the same issue.
>>>>
>>>> One thing which wasn't clear was that why do we enable a hwmod in the
>>>> first
>>>> place, if we know that we are going to skip reset?
>>>
>>> Probably to configure the idle bits. In general, we should configure the
>>> modules lazily as the driver probes as requested, and then idle the
>>> unused modules with a late_initcall.
>>
>> Okay, we were thinking of changing the hwmod code to skip enable for
>> hwmods(which have the HWMOD_INIT_NO_RESET flag) altogether. But that
>> doesn't seem like a viable option.
>>
>> I can't think of any other way of getting around this, besides making
>> control module a clock provider.
>>
>> Paul said that it's not that bad to make DRA7 CTRL module a clock
>> provider, but outside of PRCM code. I guess that would involve having
>> something along the lines of of_prcm_init() in mach-omap2/control.c
>
> That sounds like pretty much one of the things I have done here:
>
> https://github.com/t-kristo/linux-pm/tree/3.14-rc4-cm-prm-driver-wip
>
> The patches in their current form haven't been posted yet though, as
> they are waiting for some of the pre-reqs, but feel free to re-use
> something from here.

Ah nice, thanks!

Archit

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diff mbox

Patch

diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi
index 1c0f8e1..58bbdf3 100644
--- a/arch/arm/boot/dts/dra7.dtsi
+++ b/arch/arm/boot/dts/dra7.dtsi
@@ -148,6 +148,19 @@ 
 			};
 		};
 
+		ctrl_core: ctrl_core@4a002000 {
+			compatible = "ti,dra7-ctrl-core";
+			reg = <0x4a002000 0x6d0>;
+
+			ctrl_core_clocks: clocks {
+				#address-cells = <1>;
+				#size-cells = <0>;
+			};
+
+			ctrl_core_clockdomains: clockdomains {
+			};
+		};
+
 		counter32k: counter@4ae04000 {
 			compatible = "ti,omap-counter32k";
 			reg = <0x4ae04000 0x40>;