[PATCH v2 0/2] Fix V1P8_SIGNAL_ENA

[Judith Mendez <jm@ti.com>]

There are eMMC boot failures seen with V1P8_SIGNAL_ENA on Kingston
eMMC and variouse types of SD cards on Sitara K3 SoCs due to the
sequencing when enumerating to HS200 mode. Since V1P8_SIGNAL_ENA is
optional for eMMC, do not set V1P8_SIGNAL_ENA by default for eMMC.
For SD cards we shall parse DT for ti,suppress-v1p8-ena property
to determine whether to apply the quirk.

This fix was previously merged in the kernel, but was reverted due
to the "heuristics for enabling the quirk"[0]. This issue is adressed
in this patch series by adding optional ti,suppress-v1p8-ena DT property
to apply the quirk for SD.

Changes since v1:
- Drop patch for High_Speed_ENA
- Add ti,suppress-v1p8-ena for SD cards
- Add binding patch for ti,suppress-v1p8-ena
- Update cover-letter/patch descriptions according to new changes

[0] https://lore.kernel.org/linux-mmc/20250127-am654-mmc-regression-v2-1-9bb39fb12810@solid-run.com/

Judith Mendez (2):
  mmc: sdhci_am654: Add sdhci_am654_start_signal_voltage_switch
  dt-bindings: mmc: sdhci-am654: Add ti,suppress-v1p8-ena

 .../devicetree/bindings/mmc/sdhci-am654.yaml  |  5 +++
 drivers/mmc/host/sdhci_am654.c                | 32 +++++++++++++++++++
 2 files changed, 37 insertions(+)

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2.49.0