From b7a1922814c617884a3fee9b107ffb784fa4cf94 Mon Sep 17 00:00:00 2001 From: Vignesh R Date: Wed, 20 Apr 2016 17:03:00 +0530 Subject: ARM: dts: dra7x: Support QSPI MODE-0 operation at 64MHz According to Data Manual(SPRS915P) of AM57x, TI QSPI controller on DRA74(rev 1.1+)/DRA72 EVM can support up to 64MHz in MODE-0, whereas MODE-3 is limited to 48MHz. Hence, switch to MODE-0 for better throughput. Signed-off-by: Vignesh R Acked-by: Rob Herring Signed-off-by: Tony Lindgren --- Documentation/devicetree/bindings/spi/ti_qspi.txt | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'Documentation/devicetree/bindings/spi') diff --git a/Documentation/devicetree/bindings/spi/ti_qspi.txt b/Documentation/devicetree/bindings/spi/ti_qspi.txt index cc8304aa64ac..50b14f6b53a3 100644 --- a/Documentation/devicetree/bindings/spi/ti_qspi.txt +++ b/Documentation/devicetree/bindings/spi/ti_qspi.txt @@ -19,6 +19,13 @@ Optional properties: - syscon-chipselects: Handle to system control region contains QSPI chipselect register and offset of that register. +NOTE: TI QSPI controller requires different pinmux and IODelay +paramaters for Mode-0 and Mode-3 operations, which needs to be set up by +the bootloader (U-Boot). Default configuration only supports Mode-0 +operation. Hence, "spi-cpol" and "spi-cpha" DT properties cannot be +specified in the slave nodes of TI QSPI controller without appropriate +modification to bootloader. + Example: For am4372: -- cgit v1.2.3