i.MX6UL/i.MX6ULL开发常见问题
基于米尔电子 i.MX6UL/i.MX6ULL产品(V.10)
4.3如何调试出SPI?
答:客户可以根据实际硬件电路,确定硬件管脚具体用哪一个。打开内核源代码/arch/arm/boot/dts/myb-y6ull-14x14.dts。
修改dts,添加参考代码如下,具体的使用第几路spi和引脚配置根据板子的实际使用需改。
在make menuconfig 中开启spi_dev 选项;
路径SPI SUPPORT/User mode SPI device driver support
pinctrl_ecspi1: ecspi1grp {
fsl,pins = <
MX6UL_PAD_CSI_DATA07__ECSPI1_MISO 0x100b1
MX6UL_PAD_CSI_DATA06__ECSPI1_MOSI 0x100b1
MX6UL_PAD_CSI_DATA04__ECSPI1_SCLK 0x100b1
>;
};
pinctrl_ecspi1_cs: ecspi1cs {
fsl,pins = <
MX6UL_PAD_CSI_DATA05__GPIO4_IO26 0x80000000
>;
};
……..
&ecspi1 {
compatible = "fsl,imx6ul-ecspi";
fsl,spi-num-chipselects = <1>;
cs-gpios = <&gpio4 26 0>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_ecspi1 &pinctrl_ecspi1_cs>;
status = "okay";
spidev@0x00{
#address-cellss=<1>;
#size-cells=<1>;
compatible = "spidev";
spi-max-frequency = <8000000>;
reg = <0>;
};
};