设备树在根部创建设备

发布于 2025-01-31 04:33:45 字数 2329 浏览 3 评论 0原文

我正在编写一个用于位的NAND的UBOOT驱动程序，需要将其添加到设备树中。因为此设备不在任何总线上，而仅引用GPIO引脚，所以我想将其直接放在设备树根上（就像它完成的 gpio-leds）

/ {
    nand {
        status = "ok";
        compatible = "onfi,bitbang-nand";
        pinctrl-0 = <&nand_pins>;
        pinctrl-names = "default";
        nand-bus-width = <8>;
        data-gpios = <&gpio 40 0>,
        <&gpio 41 0>,
        <&gpio 42 0>,
        <&gpio 43 0>,
        <&gpio 44 0>,
        <&gpio 45 0>,
        <&gpio 46 0>,
        <&gpio 47 0>;
        ale-gpios = <&gpio 38 0>;
        cle-gpios = <&gpio 39 0>;
        nre-gpios = <&gpio 36 0>;
        nwe-gpios = <&gpio 35 0>;
        nce-gpios = <&gpio 44 0>;
        nwp-gpios = <&gpio 44 0>;
        rdy-gpios = <&gpio 47 0>;
    };
};

/blob/master/arch/mips/dts/huawei%2chg556a.dts“ rel = ” 无法识别设备，甚至在设备树节点绑定日志中甚至都不存在。当我将子节点添加到设备中时，Uboot将nand作为设备识别：

/ {
    nand {
        compatible = "onfi,bitbang-nand";
        #address-cells = <1>;
        #size-cells = <1>;
        pinctrl-0 = <&nand_pins>;
        pinctrl-names = "default";
        nand@0 {
            status = "ok";
            nand-bus-width = <8>;
            data-gpios = <&gpio 40 0>,
            <&gpio 41 0>,
            <&gpio 42 0>,
            <&gpio 43 0>,
            <&gpio 44 0>,
            <&gpio 45 0>,
            <&gpio 46 0>,
            <&gpio 47 0>;
            ale-gpios = <&gpio 38 0>;
            cle-gpios = <&gpio 39 0>;
            nre-gpios = <&gpio 36 0>;
            nwe-gpios = <&gpio 35 0>;
            nce-gpios = <&gpio 44 0>;
            nwp-gpios = <&gpio 44 0>;
            rdy-gpios = <&gpio 47 0>;
        };
    };
};

为什么第一个示例不被视为设备而第二个示例是？我找不到规范的任何相关内容。

原文

I'm writing a UBoot driver for bitbanged NAND and need to add it to the device tree.
Because this device is not on any bus and only references GPIO pins, I want to put it directly at the device tree root (like it's done for gpio-leds):

/ {
    nand {
        status = "ok";
        compatible = "onfi,bitbang-nand";
        pinctrl-0 = <&nand_pins>;
        pinctrl-names = "default";
        nand-bus-width = <8>;
        data-gpios = <&gpio 40 0>,
        <&gpio 41 0>,
        <&gpio 42 0>,
        <&gpio 43 0>,
        <&gpio 44 0>,
        <&gpio 45 0>,
        <&gpio 46 0>,
        <&gpio 47 0>;
        ale-gpios = <&gpio 38 0>;
        cle-gpios = <&gpio 39 0>;
        nre-gpios = <&gpio 36 0>;
        nwe-gpios = <&gpio 35 0>;
        nce-gpios = <&gpio 44 0>;
        nwp-gpios = <&gpio 44 0>;
        rdy-gpios = <&gpio 47 0>;
    };
};

When the device is declared as such, UBoot does not recognize the device, and it's not even present in device tree node binding log. When I add a subnode to the device, UBoot recognizes nand as a device:

/ {
    nand {
        compatible = "onfi,bitbang-nand";
        #address-cells = <1>;
        #size-cells = <1>;
        pinctrl-0 = <&nand_pins>;
        pinctrl-names = "default";
        nand@0 {
            status = "ok";
            nand-bus-width = <8>;
            data-gpios = <&gpio 40 0>,
            <&gpio 41 0>,
            <&gpio 42 0>,
            <&gpio 43 0>,
            <&gpio 44 0>,
            <&gpio 45 0>,
            <&gpio 46 0>,
            <&gpio 47 0>;
            ale-gpios = <&gpio 38 0>;
            cle-gpios = <&gpio 39 0>;
            nre-gpios = <&gpio 36 0>;
            nwe-gpios = <&gpio 35 0>;
            nce-gpios = <&gpio 44 0>;
            nwp-gpios = <&gpio 44 0>;
            rdy-gpios = <&gpio 47 0>;
        };
    };
};

Why the first example is not considered a device and the second one is? I couldn't find anything relevant in the specification.

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放肆 2025-02-07 04:33:45

这是一个愚蠢的错误。根据规范，正确的状态值是好的，而不是ok。因此，dm_scan_fdt_node in drivers/core/core/root.c在dm_scan_fdt_node中读取节点nand，并丢弃为禁用。之所以找到第二版，是因为缺席状态字段等效于启用设备。