Question

我正在编写mcp3008驱动程序而不使用iio进行学习。在这个阶段，我想要调用驱动程序的探测器。

我在DT arch / arm / boot / dts / bcm2708-rpi-b.dts中添加了我的代码

&spi0 {
    pinctrl-names = "default";
    pinctrl-0 = <&spi0_pins &spi0_cs_pins>;
    cs-gpios = <&gpio 8 1>, <&gpio 7 1>;

    spidev0: spidev@0{
            compatible = "spidev";
            reg = <0>;      /* CE0 */
            #address-cells = <1>;
            #size-cells = <0>;
            spi-max-frequency = <500000>;
    };

    spidev1: spidev@1{
            compatible = "spidev";
            reg = <1>;      /* CE1 */
            #address-cells = <1>;
            #size-cells = <0>;
            spi-max-frequency = <500000>;
    };

    /* new device for mcp3008 */  
    aartyaa_3008{
            compatible = "aartyaa_mcp3008";
            reg = <0>;
            #address-cells = <1>;
            #size-cells = <0>;
            spi-max-frequency = <1600000>;
    };
};

我的驱动程序代码看起来像

static int mcp3008_probe(struct spi_device *spi)
{
    int ret = 0;
    struct mcp3008 *mcp = NULL;
    const struct mcp3008_chip_info *chip_info;

    dev_dbg(&spi->dev, "aaartyaa came in probe, master dev = %s\n",
                     dev_name(&spi->master->dev));

    .
    .
    .
    .

}

static const struct of_device_id mcp3008_of_ids[] = {
    {
            .compatible = "aartyaa_mcp3008",
    },

    { },
};

MODULE_DEVICE_TABLE(of, mcp3008_of_ids);

static const struct spi_device_id mcp3008_ids[] = {
    {"aartyaa_mcp3008", MCP3008},
    {},
};

MODULE_DEVICE_TABLE(spi, mcp3008_ids);

static struct spi_driver mcp3008_driver = {
    .driver = {
            .name = "aartyaa_mcp3008",
            .of_match_table = of_match_ptr(mcp3008_of_ids),
    },
    .id_table = mcp3008_ids,
    .probe = mcp3008_probe,
    //.remove = devm_mcp3008_device_release,
};

module_spi_driver(mcp3008_driver);

无法注册和创建spi设备 dmesg =＆gt;

[  213.352758] spi-bcm2835 20204000.spi: chipselect 0 already in use
[  213.352781] spi_master spi0: spi_device register error /soc/spi@7e204000/aartyaa_3008
[  213.352799] spi_master spi0: Failed to create SPI device for /soc/spi@7e204000/aartyaa_3008

spi_bcm2835和spi_bcm2835aux被添加到系统中。正如我所注意到的，插入后，模块被添加到/ sys / bus / spi / drivers中。未调用探测器，因为找不到匹配设备。

如何调用驱动程序的探测器，以及如何在设备树中添加spi设备

任何帮助将不胜感激，谢谢。

Answer 1

感谢您的投入。现在我用新的替换了spi0设备。驱动程序探测被称为

Answer 2

1）您需要在以下属性的数组中添加CS GPIO，如下所示： cs-gpios = <＆gpio 8 1>，<＆gpio 7 1>，

2）并且需要在驱动程序中使用reg = <3>

在linux 4.9设备树中添加SPI从设备，用于raspbery pi

2 个答案: