Some Microcenter/Patriot SD cards and Kingston eMMC are failing init across Sitara K3 boards. Init failure is due to the sequence when V1P8_SIGNAL_ENA is set. The V1P8_SIGNAL_ENA has a timing component tied to it where if set, switch to full-cycle timing happens. The failing cards do not like change to full-cycle timing before changing bus width, so add flag to sdhci-am654 binding to suppress V1P8_SIGNAL_ENA before changing bus width. The switch to full-cycle timing should happen with HIGH_SPEED_ENA after change of bus width.
Signed-off-by: Judith Mendez jm@ti.com --- Documentation/devicetree/bindings/mmc/sdhci-am654.yaml | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/Documentation/devicetree/bindings/mmc/sdhci-am654.yaml b/Documentation/devicetree/bindings/mmc/sdhci-am654.yaml index 676a74695389..0f92bbf8e13b 100644 --- a/Documentation/devicetree/bindings/mmc/sdhci-am654.yaml +++ b/Documentation/devicetree/bindings/mmc/sdhci-am654.yaml @@ -201,6 +201,11 @@ properties: and the controller is required to be forced into Test mode to set the TESTCD bit.
+ ti,suppress-v1p8-ena: + $ref: /schemas/types.yaml#/definitions/flag + description: + When present, V1P8_SIGNAL_ENA shall be suppressed. + required: - compatible - reg