add optional property devicetree for SPI slave nodes
into devicetree so that LSB mode can be enabled by devicetree.
Signed-off-by: Zhao Qiang <B45475@xxxxxxxxxxxxx>
---
Documentation/devicetree/bindings/spi/spi-bus.txt | 4 ++++
drivers/spi/spi.c | 2 ++
2 files changed, 6 insertions(+)
diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt
index e5a4d1b..fdd9f15 100644
--- a/Documentation/devicetree/bindings/spi/spi-bus.txt
+++ b/Documentation/devicetree/bindings/spi/spi-bus.txt
@@ -55,11 +55,15 @@ contain the following properties.
chip select active high
- spi-3wire - (optional) Empty property indicating device requires
3-wire mode.
+- spi-lsb-first - (optional) Empty property indicating device requires
+ LSB first 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.
+- 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
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 23756b0..0a20a90 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1050,6 +1050,8 @@ static void of_register_spi_devices(struct spi_master *master)
spi->mode |= SPI_CS_HIGH;
if (of_find_property(nc, "spi-3wire", NULL))
spi->mode |= SPI_3WIRE;
+ if (of_find_property(nc, "spi-lsb-first", NULL))
+ spi->mode |= SPI_LSB_FIRST;
/* Device DUAL/QUAD mode */
if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
--
1.8.5
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