From a110f93d8b4672c4ad18d911f62b9e861010e83b Mon Sep 17 00:00:00 2001 From: wangyuhang Date: Sun, 1 Sep 2013 17:36:21 +0800 Subject: spi: quad: fix the name of DT property spi: quad: fix the name of DT property in patch The previous property name spi-tx-nbits and spi-rx-nbits looks not human-readable. To make it consistent with other devices, using property name spi-tx-bus-width and spi-rx-bus-width instead of the previous one specify the number of data wires that spi controller will work in. Add the specification in spi-bus.txt. Signed-off-by: wangyuhang Signed-off-by: Mark Brown --- Documentation/devicetree/bindings/spi/spi-bus.txt | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'Documentation/devicetree/bindings/spi') diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt index 296015e3c63..800dafe5b01 100644 --- a/Documentation/devicetree/bindings/spi/spi-bus.txt +++ b/Documentation/devicetree/bindings/spi/spi-bus.txt @@ -55,6 +55,16 @@ contain the following properties. chip select active high - spi-3wire - (optional) Empty property indicating device requires 3-wire mode. +- spi-tx-bus-width - (optional) The bus width(number of data wires) that + used for MOSI. Defaults to 1 if not present. +- spi-rx-bus-width - (optional) The bus width(number of data wires) that + used for MISO. Defaults to 1 if not present. + +Some SPI controllers and devices support Dual and Quad SPI transfer mode. +It allows data in SPI system transfered in 2 wires(DUAL) or 4 wires(QUAD). +Now the value that spi-tx-bus-width and spi-rx-bus-width can receive is +only 1(SINGLE), 2(DUAL) and 4(QUAD). +Dual/Quad mode is not allowed when 3-wire mode is used. If a gpio chipselect is used for the SPI slave the gpio number will be passed via the cs_gpio -- cgit v1.2.3-70-g09d2