On 26/08/24 21:41, Bryan Brattlof wrote:

On August 26, 2024 thus sayeth Dhruva Gole:

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Hi Bryan,

On Aug 23, 2024 at 16:54:30 -0500, Bryan Brattlof wrote:

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ONe power management technique available to the Cortex-A53s is their

s/ONe/One

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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

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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 :)

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describe the WKUP_MMR0_WKUP0_CTRL_MMR0_JTAG_USER_ID register to detect
the SoC variant.

Signed-off-by: Bryan Brattlof <redacted>
---
 .../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/ (local)

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