From: Vignesh R Date: Tue, 3 Oct 2017 05:19:22 +0000 (+0530) Subject: mtd: spi-nor: cadence-quadspi: Add new binding to enable loop-back circuit X-Git-Tag: v4.15-rc1~25^2~15^2~13 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=00df263560673cefe3341275990324730d4791d5;p=linux.git mtd: spi-nor: cadence-quadspi: Add new binding to enable loop-back circuit 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 Acked-by: Rob Herring Acked-by: Marek Vasut Signed-off-by: Cyrille Pitchen --- 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