diff options
author | wangyuhang <wangyuhang2014@gmail.com> | 2013-09-01 17:36:21 +0800 |
---|---|---|
committer | Nitin Garg <nitin.garg@freescale.com> | 2014-08-27 18:06:00 -0500 |
commit | ab4b5c2bfd63a57f18dd468e83d3d9be998092cc (patch) | |
tree | b8e1dc3b681932ec69b892a65571d74650e910b4 /Documentation | |
parent | 63fe694ec3c2c559b56a019fe2e74a83bcbe3dd7 (diff) |
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 <wangyuhang2014@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Huang Shijie <b32955@freescale.com>
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/devicetree/bindings/spi/spi-bus.txt | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt index 296015e3c632..800dafe5b01b 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 |