imx8qxp-mek开发板 跳接R1222,R1223,R1224,R1225，四颗电阻，把SPI0接到基本的J26端口。把J26端口的MISO和MOSI外部短接，使用spidev_test.c做自发自收测试。结果不正确。
命令行输入和输出如下：
root@imx8qxpmek:~# ./spitest -D /dev/spidev0.0 -p "123\xde\xad" -v -O -H
spi mode: 0x3
bits per word: 8
max speed: 5000000 Hz (5000 KHz)
TX | 31 32 33 DE AD __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ | 123蕲
RX | 03 83 3C 8C 0E __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ | .
root@imx8qxpmek:~# ./spitest -D /dev/spidev0.0 -p "123\xde\xad" -v -O -H
spi mode: 0x3
bits per word: 8
max speed: 5000000 Hz (5000 KHz)
TX | 31 32 33 DE AD __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ | 123蕲
RX | 03 83 3C 8C 0E __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ | .
root@imx8qxpmek:~# ./spitest -D /dev/spidev0.0 -p "123\xde\xad" -v -O -H
spi mode: 0x3
bits per word: 8
max speed: 5000000 Hz (5000 KHz)
TX | 31 32 33 DE AD __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ | 123蕲
RX | C3 87 3C 8C 0C __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ | 脟<
root@imx8qxpmek:~# ./spitest -D /dev/spidev0.0 -p "123\xde\xad" -v -O -H
spi mode: 0x3
bits per word: 8
max speed: 5000000 Hz (5000 KHz)
TX | 31 32 33 DE AD __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ | 123蕲
RX | 06 87 3C 8C 0E __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ | .
dts配置如下：
&iomuxc {
imx8qxp-mek {
pinctrl_lpspi0: lpspi0grp {
fsl,pins = <
SC_P_SPI0_SCK_ADMA_SPI0_SCK 0x0600004c
SC_P_SPI0_SDO_ADMA_SPI0_SDO 0x0600004c
SC_P_SPI0_SDI_ADMA_SPI0_SDI 0x0600004c
SC_P_SPI0_CS0_ADMA_SPI0_CS0 0x0600004c
>;
};
};
};
&lpspi0 {
#address-cells = <1>;
#size-cells = <0>;
fsl,spi-num-chipselects = <1>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_lpspi0 >;
status = "okay";
spidev0: spi@0 {
reg = <0>;
compatible = "rohm,dh2228fv";
spi-max-frequency = <5000000>;
};
};
