diff mbox series

[v4,2/8] clk: qcom: ipq5332: enable few nssnoc clocks in driver probe

Message ID 20240122-ipq5332-nsscc-v4-2-19fa30019770@quicinc.com (mailing list archive)
State New, archived
Headers show
Series Add NSS clock controller support for Qualcomm IPQ5332 | expand

Commit Message

Kathiravan Thirumoorthy Jan. 22, 2024, 5:56 a.m. UTC
gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk are
enabled by default and it's RCG is properly configured by bootloader.

Some of the NSS clocks needs these clocks to be enabled. To avoid
these clocks being disabled by clock framework, drop these entries
from the clock table and enable it in the driver probe itself.

Acked-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Kathiravan Thirumoorthy <quic_kathirav@quicinc.com>
---
 drivers/clk/qcom/gcc-ipq5332.c | 70 ++++++++----------------------------------
 1 file changed, 12 insertions(+), 58 deletions(-)

Comments

Andrew Lunn Jan. 25, 2024, 8:05 p.m. UTC | #1
On Mon, Jan 22, 2024 at 11:26:58AM +0530, Kathiravan Thirumoorthy wrote:
> gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk are
> enabled by default and it's RCG is properly configured by bootloader.

Which bootloader? Mainline barebox?

> Some of the NSS clocks needs these clocks to be enabled. To avoid
> these clocks being disabled by clock framework, drop these entries
> from the clock table and enable it in the driver probe itself.

If they are critical clocks, i would expect a device to reference
them. The CCF only disabled unused clocks in late_initcall_sync(),
which means all drivers should of probed and taken a reference on any
clocks they require.

Please correctly describe the clock tree in device tree, not hide
clocks because your DT description is not complete.

    Andrew

---
pw-bot: cr
Kathiravan Thirumoorthy Feb. 14, 2024, 9:19 a.m. UTC | #2
On 1/26/2024 1:35 AM, Andrew Lunn wrote:
> On Mon, Jan 22, 2024 at 11:26:58AM +0530, Kathiravan Thirumoorthy wrote:
>> gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk are
>> enabled by default and it's RCG is properly configured by bootloader.
> 
> Which bootloader? Mainline barebox?


Thanks for taking time to review the patches. I couldn't get time to 
respond back, sorry for the delay.

I was referring to the U-boot which is delivered as part of the QSDK. I 
will call it out explicitly in the next patch.

> 
>> Some of the NSS clocks needs these clocks to be enabled. To avoid
>> these clocks being disabled by clock framework, drop these entries
>> from the clock table and enable it in the driver probe itself.
> 
> If they are critical clocks, i would expect a device to reference
> them. The CCF only disabled unused clocks in late_initcall_sync(),
> which means all drivers should of probed and taken a reference on any
> clocks they require.


Some of the NSSCC clocks are enabled by bootloaders and CCF disables the 
same (because currently there are no consumers for these clocks 
available in the tree. These clocks are consumed by the Networking 
drivers which are being upstreamed). To access the NSSCC clocks, 
gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk clocks 
needs to be enabled, else system is going to reboot. To prevent this, I 
enabled it in probe.

However looking back, gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, 
gcc_nssnoc_nsscc_clk are consumed by the networking drivers only. So is 
it okay to drop these clocks from the GCC driver and add it back once 
the actual consumer needs it? So that we don't have to enable it in probe.

Please let me know your thoughts.


> 
> Please correctly describe the clock tree in device tree, not hide
> clocks because your DT description is not complete.
> 
>      Andrew
> 
> ---
> pw-bot: cr
Dmitry Baryshkov Feb. 14, 2024, 11:45 a.m. UTC | #3
On Wed, 14 Feb 2024 at 11:20, Kathiravan Thirumoorthy
<quic_kathirav@quicinc.com> wrote:
>
>
>
> On 1/26/2024 1:35 AM, Andrew Lunn wrote:
> > On Mon, Jan 22, 2024 at 11:26:58AM +0530, Kathiravan Thirumoorthy wrote:
> >> gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk are
> >> enabled by default and it's RCG is properly configured by bootloader.
> >
> > Which bootloader? Mainline barebox?
>
>
> Thanks for taking time to review the patches. I couldn't get time to
> respond back, sorry for the delay.
>
> I was referring to the U-boot which is delivered as part of the QSDK. I
> will call it out explicitly in the next patch.
>
> >
> >> Some of the NSS clocks needs these clocks to be enabled. To avoid
> >> these clocks being disabled by clock framework, drop these entries
> >> from the clock table and enable it in the driver probe itself.
> >
> > If they are critical clocks, i would expect a device to reference
> > them. The CCF only disabled unused clocks in late_initcall_sync(),
> > which means all drivers should of probed and taken a reference on any
> > clocks they require.
>
>
> Some of the NSSCC clocks are enabled by bootloaders and CCF disables the
> same (because currently there are no consumers for these clocks
> available in the tree. These clocks are consumed by the Networking
> drivers which are being upstreamed). To access the NSSCC clocks,
> gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk clocks
> needs to be enabled, else system is going to reboot. To prevent this, I
> enabled it in probe.
>
> However looking back, gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk,
> gcc_nssnoc_nsscc_clk are consumed by the networking drivers only. So is
> it okay to drop these clocks from the GCC driver and add it back once
> the actual consumer needs it? So that we don't have to enable it in probe.
>
> Please let me know your thoughts.

If there are no in-kernel consumers, there is no need to worry about
them at all, nobody is going to access corresponding hardware. If you
have out-of-tree modules, you also probably have your out-of-tree
overlays. So you can make use of these clocks in your overlay. I don't
see a point in dropping the clock if it is going to be readded later.
Andrew Lunn Feb. 14, 2024, 2:44 p.m. UTC | #4
On Wed, Feb 14, 2024 at 02:49:41PM +0530, Kathiravan Thirumoorthy wrote:
> 
> 
> On 1/26/2024 1:35 AM, Andrew Lunn wrote:
> > On Mon, Jan 22, 2024 at 11:26:58AM +0530, Kathiravan Thirumoorthy wrote:
> > > gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk are
> > > enabled by default and it's RCG is properly configured by bootloader.
> > 
> > Which bootloader? Mainline barebox?
> 
> 
> Thanks for taking time to review the patches. I couldn't get time to respond
> back, sorry for the delay.
> 
> I was referring to the U-boot which is delivered as part of the QSDK. I will
> call it out explicitly in the next patch.

I've never used QSDK u-boot, so i can only make comments based on my
experience with other vendors build of u-boot. That experience is, its
broken for my use cases, and i try to replace it as soon as possible
with upstream.

I generally want to TFTP boot the kernel and the DT blob. Sometimes
vendor u-boot has networking disabled. Or the TFTP client is
missing. If it is there, the IP addresses are fixed, and i don't want
to modify my network to make it compatible with the vendor
requirements. If the IP addresses can be configured, sometimes there
is no FLASH support so its not possible to actually write the
configuration to FLASH so that it does the right thing on reboot
etc...

Often the vendor u-boot is a black box, no sources. Can you give me a
git URL for the u-boot in QSDK? If the sources are open, i could at
least rebuild it with everything turned on.

But still, it is better that Linux makes no assumptions about what the
boot loader has done. That makes it much easier to change the
bootloader.

> > > Some of the NSS clocks needs these clocks to be enabled. To avoid
> > > these clocks being disabled by clock framework, drop these entries
> > > from the clock table and enable it in the driver probe itself.
> > 
> > If they are critical clocks, i would expect a device to reference
> > them. The CCF only disabled unused clocks in late_initcall_sync(),
> > which means all drivers should of probed and taken a reference on any
> > clocks they require.
> 
> 
> Some of the NSSCC clocks are enabled by bootloaders and CCF disables the
> same (because currently there are no consumers for these clocks available in
> the tree. These clocks are consumed by the Networking drivers which are
> being upstreamed).

If there is no network drivers, you don't need clocks to the
networking hardware. So CCF turning them off seems correct.

Once you have actual drivers, this should solve itself, the drivers
will consume the clocks.

> However looking back, gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk,
> gcc_nssnoc_nsscc_clk are consumed by the networking drivers only. So is it
> okay to drop these clocks from the GCC driver and add it back once the
> actual consumer needs it?

But why should you remove them. If nothing is using them, they should
be turned off.

   Andrew
Kathiravan Thirumoorthy Feb. 16, 2024, 3:22 p.m. UTC | #5
On 2/14/2024 8:14 PM, Andrew Lunn wrote:
> On Wed, Feb 14, 2024 at 02:49:41PM +0530, Kathiravan Thirumoorthy wrote:
>>
>>
>> On 1/26/2024 1:35 AM, Andrew Lunn wrote:
>>> On Mon, Jan 22, 2024 at 11:26:58AM +0530, Kathiravan Thirumoorthy wrote:
>>>> gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk are
>>>> enabled by default and it's RCG is properly configured by bootloader.
>>>
>>> Which bootloader? Mainline barebox?
>>
>>
>> Thanks for taking time to review the patches. I couldn't get time to respond
>> back, sorry for the delay.
>>
>> I was referring to the U-boot which is delivered as part of the QSDK. I will
>> call it out explicitly in the next patch.
> 
> I've never used QSDK u-boot, so i can only make comments based on my
> experience with other vendors build of u-boot. That experience is, its
> broken for my use cases, and i try to replace it as soon as possible
> with upstream.
> 
> I generally want to TFTP boot the kernel and the DT blob. Sometimes
> vendor u-boot has networking disabled. Or the TFTP client is
> missing. If it is there, the IP addresses are fixed, and i don't want
> to modify my network to make it compatible with the vendor
> requirements. If the IP addresses can be configured, sometimes there
> is no FLASH support so its not possible to actually write the
> configuration to FLASH so that it does the right thing on reboot
> etc...
> 
> Often the vendor u-boot is a black box, no sources. Can you give me a
> git URL for the u-boot in QSDK? If the sources are open, i could at
> least rebuild it with everything turned on.


You can get the source at 
https://git.codelinaro.org/clo/qsdk/oss/boot/u-boot-2016/-/tree/NHSS.QSDK.12.2?ref_type=heads

You should be able to TFTP the images, write into the flash and 
configure the IP and so on...


> 
> But still, it is better that Linux makes no assumptions about what the
> boot loader has done. That makes it much easier to change the
> bootloader.
> 
>>>> Some of the NSS clocks needs these clocks to be enabled. To avoid
>>>> these clocks being disabled by clock framework, drop these entries
>>>> from the clock table and enable it in the driver probe itself.
>>>
>>> If they are critical clocks, i would expect a device to reference
>>> them. The CCF only disabled unused clocks in late_initcall_sync(),
>>> which means all drivers should of probed and taken a reference on any
>>> clocks they require.
>>
>>
>> Some of the NSSCC clocks are enabled by bootloaders and CCF disables the
>> same (because currently there are no consumers for these clocks available in
>> the tree. These clocks are consumed by the Networking drivers which are
>> being upstreamed).
> 
> If there is no network drivers, you don't need clocks to the
> networking hardware. So CCF turning them off seems correct.


Yeah agree with your comments.

QSDK's u-boot enables the network support, so the required NSSCC clocks 
are turned ON and left it in ON state. CCF tries to disables the unused 
NSSCC clocks but system goes for reboot.


Reason being, to access the NSSCC clocks, these GCC clocks 
(gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk)
should be turned ON. But CCF disables these clocks as well due to the 
lack of consumer.


> 
> Once you have actual drivers, this should solve itself, the drivers
> will consume the clocks.


Given that, NSSCC is being built as module, there is no issue in booting 
the kernel. But if you do insmod of the nsscc-ipq5332.ko, system will 
reset.

Without the networking drivers, there is no need to install this module. 
And as you stated, once the drivers are available, there will be no issues.

So can I explain the shortcomings of installing this module without the 
networking drivers in cover letter and drop this patch all together?



> 
>> However looking back, gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk,
>> gcc_nssnoc_nsscc_clk are consumed by the networking drivers only. So is it
>> okay to drop these clocks from the GCC driver and add it back once the
>> actual consumer needs it?
> 
> But why should you remove them. If nothing is using them, they should
> be turned off.
> 
>     Andrew
Dmitry Baryshkov Feb. 16, 2024, 4:26 p.m. UTC | #6
On Fri, 16 Feb 2024 at 17:33, Kathiravan Thirumoorthy
<quic_kathirav@quicinc.com> wrote:
>
>
>
> On 2/14/2024 8:14 PM, Andrew Lunn wrote:
> > On Wed, Feb 14, 2024 at 02:49:41PM +0530, Kathiravan Thirumoorthy wrote:
> >>
> >>
> >> On 1/26/2024 1:35 AM, Andrew Lunn wrote:
> >>> On Mon, Jan 22, 2024 at 11:26:58AM +0530, Kathiravan Thirumoorthy wrote:
> >>>> gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk are
> >>>> enabled by default and it's RCG is properly configured by bootloader.
> >>>
> >>> Which bootloader? Mainline barebox?
> >>
> >>
> >> Thanks for taking time to review the patches. I couldn't get time to respond
> >> back, sorry for the delay.
> >>
> >> I was referring to the U-boot which is delivered as part of the QSDK. I will
> >> call it out explicitly in the next patch.
> >
> > I've never used QSDK u-boot, so i can only make comments based on my
> > experience with other vendors build of u-boot. That experience is, its
> > broken for my use cases, and i try to replace it as soon as possible
> > with upstream.
> >
> > I generally want to TFTP boot the kernel and the DT blob. Sometimes
> > vendor u-boot has networking disabled. Or the TFTP client is
> > missing. If it is there, the IP addresses are fixed, and i don't want
> > to modify my network to make it compatible with the vendor
> > requirements. If the IP addresses can be configured, sometimes there
> > is no FLASH support so its not possible to actually write the
> > configuration to FLASH so that it does the right thing on reboot
> > etc...
> >
> > Often the vendor u-boot is a black box, no sources. Can you give me a
> > git URL for the u-boot in QSDK? If the sources are open, i could at
> > least rebuild it with everything turned on.
>
>
> You can get the source at
> https://git.codelinaro.org/clo/qsdk/oss/boot/u-boot-2016/-/tree/NHSS.QSDK.12.2?ref_type=heads
>
> You should be able to TFTP the images, write into the flash and
> configure the IP and so on...
>
>
> >
> > But still, it is better that Linux makes no assumptions about what the
> > boot loader has done. That makes it much easier to change the
> > bootloader.
> >
> >>>> Some of the NSS clocks needs these clocks to be enabled. To avoid
> >>>> these clocks being disabled by clock framework, drop these entries
> >>>> from the clock table and enable it in the driver probe itself.
> >>>
> >>> If they are critical clocks, i would expect a device to reference
> >>> them. The CCF only disabled unused clocks in late_initcall_sync(),
> >>> which means all drivers should of probed and taken a reference on any
> >>> clocks they require.
> >>
> >>
> >> Some of the NSSCC clocks are enabled by bootloaders and CCF disables the
> >> same (because currently there are no consumers for these clocks available in
> >> the tree. These clocks are consumed by the Networking drivers which are
> >> being upstreamed).
> >
> > If there is no network drivers, you don't need clocks to the
> > networking hardware. So CCF turning them off seems correct.
>
>
> Yeah agree with your comments.
>
> QSDK's u-boot enables the network support, so the required NSSCC clocks
> are turned ON and left it in ON state. CCF tries to disables the unused
> NSSCC clocks but system goes for reboot.
>
>
> Reason being, to access the NSSCC clocks, these GCC clocks
> (gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk)
> should be turned ON. But CCF disables these clocks as well due to the
> lack of consumer.

This means that NSSCC is also a consumer of those clocks. Please fix
both DT and nsscc driver to handle NSSNOC clocks.

> > Once you have actual drivers, this should solve itself, the drivers
> > will consume the clocks.
>
>
> Given that, NSSCC is being built as module, there is no issue in booting
> the kernel. But if you do insmod of the nsscc-ipq5332.ko, system will
> reset.
>
> Without the networking drivers, there is no need to install this module.
> And as you stated, once the drivers are available, there will be no issues.
>
> So can I explain the shortcomings of installing this module without the
> networking drivers in cover letter and drop this patch all together?

No. Using allyesconfig or allmodconfig and installing the full modules
set should work.

> >> However looking back, gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk,
> >> gcc_nssnoc_nsscc_clk are consumed by the networking drivers only. So is it
> >> okay to drop these clocks from the GCC driver and add it back once the
> >> actual consumer needs it?
> >
> > But why should you remove them. If nothing is using them, they should
> > be turned off.
> >
> >     Andrew
>
Andrew Lunn Feb. 16, 2024, 5:16 p.m. UTC | #7
> You can get the source at https://git.codelinaro.org/clo/qsdk/oss/boot/u-boot-2016/-/tree/NHSS.QSDK.12.2?ref_type=heads

Cool, thanks. But is it really u-boot from 2016?

> Yeah agree with your comments.
> 
> QSDK's u-boot enables the network support, so the required NSSCC clocks are
> turned ON and left it in ON state. CCF tries to disables the unused NSSCC
> clocks but system goes for reboot.
> 
> Reason being, to access the NSSCC clocks, these GCC clocks
> (gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk)
> should be turned ON. But CCF disables these clocks as well due to the lack
> of consumer.

So there is your solution, make NSSCC a consumer of the clocks it
actually consumes. If it needs these clocks, it should get and enable
them.

	Andrew
Kathiravan Thirumoorthy Feb. 17, 2024, 3:41 p.m. UTC | #8
On 2/16/2024 10:46 PM, Andrew Lunn wrote:
>> You can get the source at https://git.codelinaro.org/clo/qsdk/oss/boot/u-boot-2016/-/tree/NHSS.QSDK.12.2?ref_type=heads
> 
> Cool, thanks. But is it really u-boot from 2016?


Yes, it is. If you want to try on IPQ95xx / IPQ53xx SoCs, you can also 
use the 2023's u-boot, which is available at [1].

[1] 
https://git.codelinaro.org/clo/qsdk/oss/boot/u-boot/-/tree/NHSS.QSDK.12.4.5?ref_type=heads

> 
>> Yeah agree with your comments.
>>
>> QSDK's u-boot enables the network support, so the required NSSCC clocks are
>> turned ON and left it in ON state. CCF tries to disables the unused NSSCC
>> clocks but system goes for reboot.
>>
>> Reason being, to access the NSSCC clocks, these GCC clocks
>> (gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk)
>> should be turned ON. But CCF disables these clocks as well due to the lack
>> of consumer.
> 
> So there is your solution, make NSSCC a consumer of the clocks it
> actually consumes. If it needs these clocks, it should get and enable
> them.


Thanks for the suggestion. I will include these clocks in NSSCC DT node 
and enable the same in the NSSCC driver probe.


> 	Andrew
Kathiravan Thirumoorthy Feb. 17, 2024, 3:44 p.m. UTC | #9
<snip>

>> Reason being, to access the NSSCC clocks, these GCC clocks
>> (gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk)
>> should be turned ON. But CCF disables these clocks as well due to the
>> lack of consumer.
> 
> This means that NSSCC is also a consumer of those clocks. Please fix
> both DT and nsscc driver to handle NSSNOC clocks.


Thanks Dmitry. I shall include these clocks in the NSSCC DT node and 
enable the same in the NSSCC driver probe.

> 
>>> Once you have actual drivers, this should solve itself, the drivers
>>> will consume the clocks.
>>
>>
>> Given that, NSSCC is being built as module, there is no issue in booting
>> the kernel. But if you do insmod of the nsscc-ipq5332.ko, system will
>> reset.
>>
>> Without the networking drivers, there is no need to install this module.
>> And as you stated, once the drivers are available, there will be no issues.
>>
>> So can I explain the shortcomings of installing this module without the
>> networking drivers in cover letter and drop this patch all together?
> 
> No. Using allyesconfig or allmodconfig and installing the full modules
> set should work.
> 


Okay, Got it. Thanks for the information.

<snip>
Dmitry Baryshkov Feb. 17, 2024, 4:45 p.m. UTC | #10
On Sat, 17 Feb 2024 at 17:45, Kathiravan Thirumoorthy
<quic_kathirav@quicinc.com> wrote:
>
>
> <snip>
>
> >> Reason being, to access the NSSCC clocks, these GCC clocks
> >> (gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk)
> >> should be turned ON. But CCF disables these clocks as well due to the
> >> lack of consumer.
> >
> > This means that NSSCC is also a consumer of those clocks. Please fix
> > both DT and nsscc driver to handle NSSNOC clocks.
>
>
> Thanks Dmitry. I shall include these clocks in the NSSCC DT node and
> enable the same in the NSSCC driver probe.

Or use them through pm_clk. This might be better, as the system
doesn't need these clocks if NSSCC is suspended.

>
> >
> >>> Once you have actual drivers, this should solve itself, the drivers
> >>> will consume the clocks.
> >>
> >>
> >> Given that, NSSCC is being built as module, there is no issue in booting
> >> the kernel. But if you do insmod of the nsscc-ipq5332.ko, system will
> >> reset.
> >>
> >> Without the networking drivers, there is no need to install this module.
> >> And as you stated, once the drivers are available, there will be no issues.
> >>
> >> So can I explain the shortcomings of installing this module without the
> >> networking drivers in cover letter and drop this patch all together?
> >
> > No. Using allyesconfig or allmodconfig and installing the full modules
> > set should work.
> >
>
>
> Okay, Got it. Thanks for the information.
>
> <snip>
Kathiravan Thirumoorthy Feb. 18, 2024, 4:29 a.m. UTC | #11
On 2/17/2024 10:15 PM, Dmitry Baryshkov wrote:
> On Sat, 17 Feb 2024 at 17:45, Kathiravan Thirumoorthy
> <quic_kathirav@quicinc.com> wrote:
>>
>>
>> <snip>
>>
>>>> Reason being, to access the NSSCC clocks, these GCC clocks
>>>> (gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk)
>>>> should be turned ON. But CCF disables these clocks as well due to the
>>>> lack of consumer.
>>>
>>> This means that NSSCC is also a consumer of those clocks. Please fix
>>> both DT and nsscc driver to handle NSSNOC clocks.
>>
>>
>> Thanks Dmitry. I shall include these clocks in the NSSCC DT node and
>> enable the same in the NSSCC driver probe.
> 
> Or use them through pm_clk. This might be better, as the system
> doesn't need these clocks if NSSCC is suspended.


IPQ53XX SoC doesn't support the PM(suspend / resume) functionality, so 
that, can I enable these clocks in NSSCC driver probe itself?


> 
>>
>>>
>>>>> Once you have actual drivers, this should solve itself, the drivers
>>>>> will consume the clocks.
>>>>
>>>>
>>>> Given that, NSSCC is being built as module, there is no issue in booting
>>>> the kernel. But if you do insmod of the nsscc-ipq5332.ko, system will
>>>> reset.
>>>>
>>>> Without the networking drivers, there is no need to install this module.
>>>> And as you stated, once the drivers are available, there will be no issues.
>>>>
>>>> So can I explain the shortcomings of installing this module without the
>>>> networking drivers in cover letter and drop this patch all together?
>>>
>>> No. Using allyesconfig or allmodconfig and installing the full modules
>>> set should work.
>>>
>>
>>
>> Okay, Got it. Thanks for the information.
>>
>> <snip>
> 
> 
>
Konrad Dybcio Feb. 19, 2024, 10:16 a.m. UTC | #12
On 18.02.2024 05:29, Kathiravan Thirumoorthy wrote:
> 
> 
> On 2/17/2024 10:15 PM, Dmitry Baryshkov wrote:
>> On Sat, 17 Feb 2024 at 17:45, Kathiravan Thirumoorthy
>> <quic_kathirav@quicinc.com> wrote:
>>>
>>>
>>> <snip>
>>>
>>>>> Reason being, to access the NSSCC clocks, these GCC clocks
>>>>> (gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk)
>>>>> should be turned ON. But CCF disables these clocks as well due to the
>>>>> lack of consumer.
>>>>
>>>> This means that NSSCC is also a consumer of those clocks. Please fix
>>>> both DT and nsscc driver to handle NSSNOC clocks.
>>>
>>>
>>> Thanks Dmitry. I shall include these clocks in the NSSCC DT node and
>>> enable the same in the NSSCC driver probe.
>>
>> Or use them through pm_clk. This might be better, as the system
>> doesn't need these clocks if NSSCC is suspended.
> 
> 
> IPQ53XX SoC doesn't support the PM(suspend / resume) functionality, so that, can I enable these clocks in NSSCC driver probe itself?

Surely the platform can s2idle..

Konrad
Dmitry Baryshkov Feb. 19, 2024, 10:23 a.m. UTC | #13
On Sun, 18 Feb 2024 at 06:29, Kathiravan Thirumoorthy
<quic_kathirav@quicinc.com> wrote:
>
>
>
> On 2/17/2024 10:15 PM, Dmitry Baryshkov wrote:
> > On Sat, 17 Feb 2024 at 17:45, Kathiravan Thirumoorthy
> > <quic_kathirav@quicinc.com> wrote:
> >>
> >>
> >> <snip>
> >>
> >>>> Reason being, to access the NSSCC clocks, these GCC clocks
> >>>> (gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk)
> >>>> should be turned ON. But CCF disables these clocks as well due to the
> >>>> lack of consumer.
> >>>
> >>> This means that NSSCC is also a consumer of those clocks. Please fix
> >>> both DT and nsscc driver to handle NSSNOC clocks.
> >>
> >>
> >> Thanks Dmitry. I shall include these clocks in the NSSCC DT node and
> >> enable the same in the NSSCC driver probe.
> >
> > Or use them through pm_clk. This might be better, as the system
> > doesn't need these clocks if NSSCC is suspended.
>
>
> IPQ53XX SoC doesn't support the PM(suspend / resume) functionality, so
> that, can I enable these clocks in NSSCC driver probe itself?

There is a difference between PM (suspend/resume) and runtime PM.
Kathiravan Thirumoorthy Feb. 23, 2024, 10:18 a.m. UTC | #14
On 2/19/2024 3:53 PM, Dmitry Baryshkov wrote:
> On Sun, 18 Feb 2024 at 06:29, Kathiravan Thirumoorthy
> <quic_kathirav@quicinc.com> wrote:
>>
>>
>>
>> On 2/17/2024 10:15 PM, Dmitry Baryshkov wrote:
>>> On Sat, 17 Feb 2024 at 17:45, Kathiravan Thirumoorthy
>>> <quic_kathirav@quicinc.com> wrote:
>>>>
>>>>
>>>> <snip>
>>>>
>>>>>> Reason being, to access the NSSCC clocks, these GCC clocks
>>>>>> (gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk)
>>>>>> should be turned ON. But CCF disables these clocks as well due to the
>>>>>> lack of consumer.
>>>>>
>>>>> This means that NSSCC is also a consumer of those clocks. Please fix
>>>>> both DT and nsscc driver to handle NSSNOC clocks.
>>>>
>>>>
>>>> Thanks Dmitry. I shall include these clocks in the NSSCC DT node and
>>>> enable the same in the NSSCC driver probe.
>>>
>>> Or use them through pm_clk. This might be better, as the system
>>> doesn't need these clocks if NSSCC is suspended.
>>
>>
>> IPQ53XX SoC doesn't support the PM(suspend / resume) functionality, so
>> that, can I enable these clocks in NSSCC driver probe itself?
> 
> There is a difference between PM (suspend/resume) and runtime PM.
> 
> 

Thanks Dmitry. IIUC your question correctly, runtime PM for the 
peripherals are not supported (except CPU cores which supports DVFS). 
Since these are router based products, once system is powered on, all 
the peripherals are configured to the required frequency and it will be 
never go into low power modes.

Please let me know if this answers your questions.
Dmitry Baryshkov March 5, 2024, 6:41 a.m. UTC | #15
On Fri, 23 Feb 2024 at 12:18, Kathiravan Thirumoorthy
<quic_kathirav@quicinc.com> wrote:
>
>
>
> On 2/19/2024 3:53 PM, Dmitry Baryshkov wrote:
> > On Sun, 18 Feb 2024 at 06:29, Kathiravan Thirumoorthy
> > <quic_kathirav@quicinc.com> wrote:
> >>
> >>
> >>
> >> On 2/17/2024 10:15 PM, Dmitry Baryshkov wrote:
> >>> On Sat, 17 Feb 2024 at 17:45, Kathiravan Thirumoorthy
> >>> <quic_kathirav@quicinc.com> wrote:
> >>>>
> >>>>
> >>>> <snip>
> >>>>
> >>>>>> Reason being, to access the NSSCC clocks, these GCC clocks
> >>>>>> (gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk)
> >>>>>> should be turned ON. But CCF disables these clocks as well due to the
> >>>>>> lack of consumer.
> >>>>>
> >>>>> This means that NSSCC is also a consumer of those clocks. Please fix
> >>>>> both DT and nsscc driver to handle NSSNOC clocks.
> >>>>
> >>>>
> >>>> Thanks Dmitry. I shall include these clocks in the NSSCC DT node and
> >>>> enable the same in the NSSCC driver probe.
> >>>
> >>> Or use them through pm_clk. This might be better, as the system
> >>> doesn't need these clocks if NSSCC is suspended.
> >>
> >>
> >> IPQ53XX SoC doesn't support the PM(suspend / resume) functionality, so
> >> that, can I enable these clocks in NSSCC driver probe itself?
> >
> > There is a difference between PM (suspend/resume) and runtime PM.
> >
> >
>
> Thanks Dmitry. IIUC your question correctly, runtime PM for the
> peripherals are not supported (except CPU cores which supports DVFS).
> Since these are router based products, once system is powered on, all
> the peripherals are configured to the required frequency and it will be
> never go into low power modes.
>
> Please let me know if this answers your questions.

It seems there is a misunderstanding somewhere. Runtime PM allows the
Linux kernel to disable temporary unused devices at runtime. E.g. if
the NSS is switched off, the kernel can switch NSSCC off too, cutting
the power. It has nothing to do with the frequency of the device /
clock or with the product being a router or a mobile device.
diff mbox series

Patch

diff --git a/drivers/clk/qcom/gcc-ipq5332.c b/drivers/clk/qcom/gcc-ipq5332.c
index 66d5399798fe..38a570b68813 100644
--- a/drivers/clk/qcom/gcc-ipq5332.c
+++ b/drivers/clk/qcom/gcc-ipq5332.c
@@ -1672,24 +1672,6 @@  static struct clk_branch gcc_nssnoc_atb_clk = {
 	},
 };
 
-static struct clk_branch gcc_nssnoc_nsscc_clk = {
-	.halt_reg = 0x17030,
-	.halt_check = BRANCH_HALT,
-	.clkr = {
-		.enable_reg = 0x17030,
-		.enable_mask = BIT(0),
-		.hw.init = &(const struct clk_init_data) {
-			.name = "gcc_nssnoc_nsscc_clk",
-			.parent_hws = (const struct clk_hw*[]) {
-				&gcc_pcnoc_bfdcd_clk_src.clkr.hw,
-			},
-			.num_parents = 1,
-			.flags = CLK_SET_RATE_PARENT,
-			.ops = &clk_branch2_ops,
-		},
-	},
-};
-
 static struct clk_branch gcc_nssnoc_qosgen_ref_clk = {
 	.halt_reg = 0x1701c,
 	.halt_check = BRANCH_HALT,
@@ -2585,42 +2567,6 @@  static struct clk_branch gcc_snoc_lpass_cfg_clk = {
 	},
 };
 
-static struct clk_branch gcc_snoc_nssnoc_1_clk = {
-	.halt_reg = 0x17090,
-	.halt_check = BRANCH_HALT,
-	.clkr = {
-		.enable_reg = 0x17090,
-		.enable_mask = BIT(0),
-		.hw.init = &(const struct clk_init_data) {
-			.name = "gcc_snoc_nssnoc_1_clk",
-			.parent_hws = (const struct clk_hw*[]) {
-				&gcc_system_noc_bfdcd_clk_src.clkr.hw,
-			},
-			.num_parents = 1,
-			.flags = CLK_SET_RATE_PARENT,
-			.ops = &clk_branch2_ops,
-		},
-	},
-};
-
-static struct clk_branch gcc_snoc_nssnoc_clk = {
-	.halt_reg = 0x17084,
-	.halt_check = BRANCH_HALT,
-	.clkr = {
-		.enable_reg = 0x17084,
-		.enable_mask = BIT(0),
-		.hw.init = &(const struct clk_init_data) {
-			.name = "gcc_snoc_nssnoc_clk",
-			.parent_hws = (const struct clk_hw*[]) {
-				&gcc_system_noc_bfdcd_clk_src.clkr.hw,
-			},
-			.num_parents = 1,
-			.flags = CLK_SET_RATE_PARENT,
-			.ops = &clk_branch2_ops,
-		},
-	},
-};
-
 static struct clk_branch gcc_snoc_pcie3_1lane_1_m_clk = {
 	.halt_reg = 0x2e050,
 	.halt_check = BRANCH_HALT,
@@ -3330,7 +3276,6 @@  static struct clk_regmap *gcc_ipq5332_clocks[] = {
 	[GCC_NSSCC_CLK] = &gcc_nsscc_clk.clkr,
 	[GCC_NSSCFG_CLK] = &gcc_nsscfg_clk.clkr,
 	[GCC_NSSNOC_ATB_CLK] = &gcc_nssnoc_atb_clk.clkr,
-	[GCC_NSSNOC_NSSCC_CLK] = &gcc_nssnoc_nsscc_clk.clkr,
 	[GCC_NSSNOC_QOSGEN_REF_CLK] = &gcc_nssnoc_qosgen_ref_clk.clkr,
 	[GCC_NSSNOC_SNOC_1_CLK] = &gcc_nssnoc_snoc_1_clk.clkr,
 	[GCC_NSSNOC_SNOC_CLK] = &gcc_nssnoc_snoc_clk.clkr,
@@ -3398,8 +3343,6 @@  static struct clk_regmap *gcc_ipq5332_clocks[] = {
 	[GCC_SDCC1_APPS_CLK_SRC] = &gcc_sdcc1_apps_clk_src.clkr,
 	[GCC_SLEEP_CLK_SRC] = &gcc_sleep_clk_src.clkr,
 	[GCC_SNOC_LPASS_CFG_CLK] = &gcc_snoc_lpass_cfg_clk.clkr,
-	[GCC_SNOC_NSSNOC_1_CLK] = &gcc_snoc_nssnoc_1_clk.clkr,
-	[GCC_SNOC_NSSNOC_CLK] = &gcc_snoc_nssnoc_clk.clkr,
 	[GCC_SNOC_PCIE3_1LANE_1_M_CLK] = &gcc_snoc_pcie3_1lane_1_m_clk.clkr,
 	[GCC_SNOC_PCIE3_1LANE_1_S_CLK] = &gcc_snoc_pcie3_1lane_1_s_clk.clkr,
 	[GCC_SNOC_PCIE3_1LANE_M_CLK] = &gcc_snoc_pcie3_1lane_m_clk.clkr,
@@ -3660,7 +3603,18 @@  static const struct qcom_cc_desc gcc_ipq5332_desc = {
 
 static int gcc_ipq5332_probe(struct platform_device *pdev)
 {
-	return qcom_cc_probe(pdev, &gcc_ipq5332_desc);
+	struct regmap *regmap;
+
+	regmap = qcom_cc_map(pdev, &gcc_ipq5332_desc);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	/* Keep the critical clocks always-On */
+	regmap_update_bits(regmap, 0x17030, BIT(0), BIT(0)); /* gcc_nssnoc_nsscc_clk */
+	regmap_update_bits(regmap, 0x17084, BIT(0), BIT(0)); /* gcc_snoc_nssnoc_clk */
+	regmap_update_bits(regmap, 0x17090, BIT(0), BIT(0)); /* gcc_snoc_nssnoc_1_clk */
+
+	return qcom_cc_really_probe(pdev, &gcc_ipq5332_desc, regmap);
 }
 
 static const struct of_device_id gcc_ipq5332_match_table[] = {