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-rw-r--r--Documentation/devicetree/bindings/spi/spi-bus.txt4
1 files changed, 3 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt
index e5a4d1b4acfe..bbaa857dd68f 100644
--- a/Documentation/devicetree/bindings/spi/spi-bus.txt
+++ b/Documentation/devicetree/bindings/spi/spi-bus.txt
@@ -55,13 +55,15 @@ contain the following properties.
55 chip select active high 55 chip select active high
56- spi-3wire - (optional) Empty property indicating device requires 56- spi-3wire - (optional) Empty property indicating device requires
57 3-wire mode. 57 3-wire mode.
58- spi-lsb-first - (optional) Empty property indicating device requires
59 LSB first mode.
58- spi-tx-bus-width - (optional) The bus width(number of data wires) that 60- spi-tx-bus-width - (optional) The bus width(number of data wires) that
59 used for MOSI. Defaults to 1 if not present. 61 used for MOSI. Defaults to 1 if not present.
60- spi-rx-bus-width - (optional) The bus width(number of data wires) that 62- spi-rx-bus-width - (optional) The bus width(number of data wires) that
61 used for MISO. Defaults to 1 if not present. 63 used for MISO. Defaults to 1 if not present.
62 64
63Some SPI controllers and devices support Dual and Quad SPI transfer mode. 65Some SPI controllers and devices support Dual and Quad SPI transfer mode.
64It allows data in SPI system transfered in 2 wires(DUAL) or 4 wires(QUAD). 66It allows data in the SPI system to be transferred in 2 wires(DUAL) or 4 wires(QUAD).
65Now the value that spi-tx-bus-width and spi-rx-bus-width can receive is 67Now the value that spi-tx-bus-width and spi-rx-bus-width can receive is
66only 1(SINGLE), 2(DUAL) and 4(QUAD). 68only 1(SINGLE), 2(DUAL) and 4(QUAD).
67Dual/Quad mode is not allowed when 3-wire mode is used. 69Dual/Quad mode is not allowed when 3-wire mode is used.