Cadence QSPI IP has a adapted loop-back circuit which can be enabled by setting BYPASS field to 0 in READCAPTURE register. It enables use of QSPI return clock to latch the data rather than the internal QSPI reference clock. For high speed operations, adapted loop-back circuit using QSPI return clock helps to increase data valid window. Add DT parameter cdns,rclk-en to help enable adapted loop-back circuit for boards which do have QSPI return clock provided. Update binding documentation for the same. Signed-off-by: Vignesh R <vigneshr@xxxxxx> --- Documentation/devicetree/bindings/mtd/cadence-quadspi.txt | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt b/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt index 7dbe3bd9ac56..bb2075df9b38 100644 --- a/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt +++ b/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt @@ -16,6 +16,9 @@ Required properties: Optional properties: - cdns,is-decoded-cs : Flag to indicate whether decoder is used or not. +- cdns,rclk-en : Flag to indicate that QSPI return clock is used to latch + the read data rather than the QSPI clock. Make sure that QSPI return + clock is populated on the board before using this property. Optional subnodes: Subnodes of the Cadence Quad SPI controller are spi slave nodes with additional -- 2.14.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
