[PATCH v5 0/2] Add SMI reset and clamp for MediaTek MT8188 SoC

From: Friday Yang
Date: Tue Mar 11 2025 - 08:30:20 EST


Based on tag: next-20250307, 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 v5:
- Use 'devm_pm_runtime_enable' instead of 'pm_runtime_enable'.
- Remove 'pm_runtime_disable' in 'mtk_smi_common_remove' and
'mtk_smi_larb_remove'.

v4:
https://lore.kernel.org/lkml/20250221074846.14105-2-friday.yang@xxxxxxxxxxxx/
https://lore.kernel.org/lkml/20250221074846.14105-3-friday.yang@xxxxxxxxxxxx/

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 | 150 +++++++++++++++++-
3 files changed, 164 insertions(+), 7 deletions(-)

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2.46.0