SPI

数据结构

spi_transfer

struct spi_transfer - a read/write buffer pair
@tx_buf: data to be written (dma-safe memory), or NULL
@rx_buf: data to be read (dma-safe memory), or NULL
@len: size of rx and tx buffers (in bytes)
@cs_change: affects chipselect after this transfer completes

Debug

read and write test

cat /dev/ttysWK0
echo 1 > /dev/ttysWK0

测试脚本

i=1
while true
do
if [ $i -eq 10 ]
then
(( i=1 ))
fi
echo $i > /dev/ttysWK0
sleep 1
(( i+=1 ))
done