imx8qxp-mek lpspi问题

[petersonhou]

我们在imx8qxp-mek开发板上测试LPSPI模块的SPI功能，将fsl-imx8qxp-mek.dtsi文件添加了imx8qxp-lpddr4-val-lpspi.dts/imx8qxp-lpddr4-val-lpspi.dts中的

pinctrl_lpspi0: lpspi0grp {
      fsl,pins = <
                     IMX8QXP_SPI0_SCK_ADMA_SPI0_SCK        0x0600004c
                     IMX8QXP_SPI0_SDO_ADMA_SPI0_SDO       0x0600004c
                     IMX8QXP_SPI0_SDI_ADMA_SPI0_SDI           0x0600004c
        >;
};

pinctrl_lpspi0_cs: lpspi0cs {
        fsl,pins = <
                     IMX8QXP_SPI0_CS0_LSIO_GPIO1_IO08 0x21
         >;
};

&lpspi0 {
            fsl,spi-num-chipselects = <1>;
            pinctrl-names = "default";
            pinctrl-0 = <&pinctrl_lpspi0 &pinctrl_lpspi0_cs>;
            cs-gpios = <&lsio_gpio1 8 GPIO_ACTIVE_LOW>; //使用gpio 做片选
            status = "okay";
            spidev0: spi@0 { 
                           reg = <0>;
                           compatible = "rohm,xxxx";
                           spi-max-frequency = <50000000>;

               };

};

启动开发板，spi-fsl-lpspi.c的控制器驱动加载注册成功并顺利完成probe函数

但出现一下问题：

1.在/dev/下找不到spidev*设备

2.对应片选信号引脚一直是低电平，并没有像驱动中写的SPI_CS_HIGH

3.我自己做了个slave设备驱动，在insmod之后CS被拉高，且在调用spi_sync()后，CS有拉低且SCK出现时钟，但MOSI没有电平变化

期待您的回复，谢谢！

[jimmychan]

do you select the spidev in menuconfig?

[petersonhou]

CONFIG_SPI=y

CONFIG_SPI_FSL_LPSPI=y

CONFIG_SPI_IMX=y

CONFIG_SPI_SPIDEV=y

CONFIG_SPI_MASTER=y

CONFIG_SPI_SLAVE=y

都选了

[terry_lv]

compatible = "rohm,xxxx" 这个改成 compatible = "rohm,dh2228fv"试一下？

[petersonhou]

可以找到spidev0.0了，但依然没有输出信号，这个dh2228fv是个虚拟的设备驱动是吗？是为了实例化lpspi controller吗？

[terry_lv]

这个是spidev.c里面定义的compatible string.

static const struct of_device_id spidev_dt_ids[] = {
    { .compatible = "rohm,dh2228fv" },
    { .compatible = "lineartechnology,ltc2488" },
    { .compatible = "ge,achc" },
    { .compatible = "semtech,sx1301" },
    { .compatible = "lwn,bk4" },
    { .compatible = "dh,dhcom-board" },
    { .compatible = "menlo,m53cpld" },
    {},
};