[PATCH v8 0/2] Add SMI reset and clamp for MediaTek MT8188 SoC

[Friday Yang]

Based on tag: next-20250521, linux-next/master

On the MediaTek MT8188 SoC platform, we encountered power-off failures
and SMI bus hang issues during camera stress tests. The issue arises
because bus glitches are sometimes produced when MTCMOS powers on or
off. While this is fairly normal, the software must handle these
glitches to avoid mistaking them for transaction signals. What's
more, this issue emerged only after the initial upstreaming of SMI
driver.

The software solutions can be summarized as follows:

1. Use CLAMP to disable the SMI sub-common port after turning off the
   LARB CG and before turning off the LARB MTCMOS.
2. Use CLAMP to disable/enable the SMI sub-common port.
3. Implement an AXI reset for SMI LARBs.

Changes v8:
- We replaced 'pm_runtime_enable' with 'devm_pm_runtime_enable' in the
  v6 patch. This changed the order of cleanup, and reviewers expressed
  concerns that it could introduce unexpected issues. So I discard this
  change and continue using 'pm_runtime_enable'. We need to conduct
  further investigation to determine if there are any issues related
  to the cleanup order. This might be resolved in the future, but for
  now, we just maintain the current status.

v7:
https://lore.kernel.org/lkml/20250430094545.23932-2-friday.yang@mediatek.com/
https://lore.kernel.org/lkml/20250430094545.23932-3-friday.yang@mediatek.com/

friday.yang (2):
  dt-bindings: memory: mediatek: Add SMI reset and clamp for MT8188
  memory: mtk-smi: mt8188: Add SMI reset and clamp for MT8188

 .../mediatek,smi-common.yaml                  |   2 +
 .../memory-controllers/mediatek,smi-larb.yaml |  19 +++
 drivers/memory/mtk-smi.c                      | 133 ++++++++++++++++++
 3 files changed, 154 insertions(+)

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2.46.0