[PATCH RFC 0/7] Support Tegra210 actmon for dynamic EMC scaling

[Aaron Kling via B4 Relay <devnull+webgeek1234.gmail.com@kernel.org>]

This series adds interconnect support to tegra210 MC and EMC, then
enables actmon. This enables dynamic emc scaling.

This series is marked RFC for two reasons:

1) Calculating rate from bandwidth usage results in double the expected
   rate. I thought this might be due to the ram being 64-bit, but the
   related CFG5 register reports 32-bit on both p2371-2180 and
   p3450-0000. I'm using the calculation used for Tegra124 and haven't
   seen seen anything obviously different between the ram handling on
   these archs to cause a different result. I have considered that the
   number of channels might affect the reporting, and factoring in that
   variable does result in the correct rate, but I don't want to assume
   that's correct without confirmation.

2) I am seeing intermittent instability when transitioning to rates of
   204 MHz or below on p2371-2180. I have noted that if the first
   transition to such a state works, then it continues to work for the
   rest of that boot cycle. But the kernel will often panic the first
   time it tries to downclock. I suspect this is a pre-existing issue
   only brought to light now because nothing would ever lower the clock
   rate previously.

Signed-off-by: Aaron Kling <webgeek1234@gmail.com>
---
Aaron Kling (7):
      dt-bindings: memory: tegra210: Add memory client IDs
      dt-bindings: devfreq: tegra30-actmon: Add Tegra124 fallback for Tegra210
      soc: tegra: fuse: speedo-tegra210: Add soc speedo 2
      memory: tegra210: Support interconnect framework
      arm64: tegra: tegra210: Add actmon
      arm64: tegra: Add interconnect properties to Tegra210 device-tree
      arm64: tegra: Add OPP tables on Tegra210

 .../bindings/devfreq/nvidia,tegra30-actmon.yaml    |  13 +-
 .../boot/dts/nvidia/tegra210-peripherals-opp.dtsi  | 135 ++++++++++
 arch/arm64/boot/dts/nvidia/tegra210.dtsi           |  43 ++++
 drivers/memory/tegra/Kconfig                       |   1 +
 drivers/memory/tegra/tegra210-emc-core.c           | 276 ++++++++++++++++++++-
 drivers/memory/tegra/tegra210-emc.h                |  25 ++
 drivers/memory/tegra/tegra210.c                    |  81 ++++++
 drivers/soc/tegra/fuse/speedo-tegra210.c           |   1 +
 include/dt-bindings/memory/tegra210-mc.h           |  58 +++++
 9 files changed, 626 insertions(+), 7 deletions(-)
---
base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585
change-id: 20250822-t210-actmon-34904ce7ed0c
prerequisite-change-id: 20250812-tegra210-speedo-470691e8b8cc:v1
prerequisite-patch-id: 81859c81abbe79aed1cfbc95b4f5bcdc5637d6bd
prerequisite-patch-id: 98bda8855bcc57c59b2231b7808d4478301afe68
prerequisite-patch-id: 6e0b69d42ea542dc9f58b410abd5974644f75dc4
prerequisite-patch-id: 9e3b9b2fdb8d9c2264dfa7641d1aec84fb7aedd9
prerequisite-patch-id: ef4bcc4ddba7898b188fb3fc6e414a2662183f91

Best regards,
-- 
Aaron Kling <webgeek1234@gmail.com>