This parameter should also be supported.
Signed-off-by: Simon Glass sjg@chromium.org ---
doc/device-tree-bindings/spi/spi-bus.txt | 2 ++ drivers/spi/spi.c | 2 ++ 2 files changed, 4 insertions(+)
diff --git a/doc/device-tree-bindings/spi/spi-bus.txt b/doc/device-tree-bindings/spi/spi-bus.txt index 800dafe..5c8720a 100644 --- a/doc/device-tree-bindings/spi/spi-bus.txt +++ b/doc/device-tree-bindings/spi/spi-bus.txt @@ -59,6 +59,8 @@ contain the following properties. 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. +- spi-half-duplex - (optional) Indicates that the SPI bus should wait for + a header byte before reading data from the slave.
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). diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 7ddea9b..7d81fbd 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -53,6 +53,8 @@ struct spi_slave *spi_base_setup_slave_fdt(const void *blob, int busnum, mode |= SPI_CPHA; if (fdtdec_get_bool(blob, node, "spi-cs-high")) mode |= SPI_CS_HIGH; + if (fdtdec_get_bool(blob, node, "spi-half-duplex")) + mode |= SPI_PREAMBLE; return spi_setup_slave(busnum, cs, max_hz, mode); } #endif