On 26/08/24 21:41, Bryan Brattlof wrote:
> On August 26, 2024 thus sayeth Dhruva Gole:
>> Hi Bryan,
>>
>> On Aug 23, 2024 at 16:54:30 -0500, Bryan Brattlof wrote:
>>> ONe power management technique available to the Cortex-A53s is their
>>
>> s/ONe/One
>>
>>> ability to dynamically scale their frequency across the device's
>>> Operating Performance Points (OPP)
>>>
>>> The OPPs available for the Cortex-A53s on the AM62Px can vary based on
>>> the silicon variant used. The SoC variant is encoded into the
>>> WKUP_MMR0_WKUP0_CTRL_MMR0_JTAG_USER_ID register which is used to limit
>>> the OPP entries the SoC supports. A table of all these variants can be
>>> found in its data sheet[0] for the AM62Px processor family.
>>
>> Error 404! Not found [0] ;)
>>
>
> Oops. I'll fix these up
>
>>>
>>> Add the OPP table into the SoC's ftdi file along with the syscon node to
>>
>> What is ftdi?
>
> FTDI is a chip, what I tried to type out was fdti or Flattened Device
> Tree Includes :)
>
>>
>>> describe the WKUP_MMR0_WKUP0_CTRL_MMR0_JTAG_USER_ID register to detect
>>> the SoC variant.
>>>
>>> Signed-off-by: Bryan Brattlof <bb@xxxxxx>
>>> ---
>>> .../boot/dts/ti/k3-am62p-j722s-common-wakeup.dtsi | 5 +++
>>> arch/arm64/boot/dts/ti/k3-am62p5.dtsi | 47 ++++++++++++++++++++++
>>> 2 files changed, 52 insertions(+)
>>>
>>> diff --git a/arch/arm64/boot/dts/ti/k3-am62p-j722s-common-wakeup.dtsi b/arch/arm64/boot/dts/ti/k3-am62p-j722s-common-wakeup.dtsi
>>> index 315d0092e7366..6f32135f00a55 100644
>>> --- a/arch/arm64/boot/dts/ti/k3-am62p-j722s-common-wakeup.dtsi
>>> +++ b/arch/arm64/boot/dts/ti/k3-am62p-j722s-common-wakeup.dtsi
>>> @@ -20,6 +20,11 @@ chipid: chipid@14 {
>>> bootph-all;
>>> };
>>>
>>> + opp_efuse_table: syscon@18 {
>>> + compatible = "ti,am62-opp-efuse-table", "syscon";
>>
>> Huh, curious why I don't see this particular compatible in am62 itself..
>> Also, I am still not clear where this discussion got left off: (If it's
>> related)
>> https://lore.kernel.org/all/5chxjwybmsxq73pagtlw4zr2asbtxov7ezrpn5j37cr77bmepa@fejdlxomfgae/
>>
>> In AM625, I see
>> k3-am625.dtsi:111: col 14: syscon = <&wkup_conf>;
>>
>> But the approach you've used here seems different. Is there a
>> justification given on which one should be used/why somewhere that I can
>> refer?
>
> Labeling the entire &wkup_conf as a syscon node is kinda abusing what
> the syscon node is used for. There are a lot of things inside that
> WKUP_CTRL_MMR that do not belong under the miscellaneous registers
> category. For the 62A and 62P we've chosen to label &wkup_conf as a bus
> with little syscon sub-nodes inside of it.
>
> I don't think the discussion[0] ever finalized but we started going that
> direction with new SoCs, looks like the older SoCs never received the
> cleanup.
This patch seems to be in the right direction. Marking entire wkup_conf
as "syscon", "simple-mfd" is wrong and needs to be addressed in
k3-am62-wakeup.dtsi similar to how other child-nodes in wkup_conf are
implemented in same file.
[...]
--
Regards
Vignesh
