在Amlogic Meson G12A平台上为ENG28J60芯片编写设备树（DTS）覆盖

Question

我需要编写一个 .dts 覆盖文件，以便在 Radxa Zero（即 Amlogic Meson G12A<）上使用 Microchip enc28j60 /code> 平台通过 SPI。我使用的内核是 来自 radxa 的​​ 5.10 。

从完全不知道我在做什么开始，我最终得到了以下覆盖：

/dts-v1/;
/plugin/;

#include <dt-bindings/interrupt-controller/irq.h>
#include <dt-bindings/gpio/meson-g12a-gpio.h>

&spicc1 {
    // spicc1 defined in meson-g12-common.dtsi

    // See meson-g12a-spi-spidev.dts
    pinctrl-0 = <&spicc1_pins &spicc1_ss0_pins>;
    pinctrl-names = "default";
    // handled by `param_spidev_spi_bus` and meson-fixup.scr-cmd for the spi-spidev overlay
    status = "okay";

    #address-cells = <1>;
    #size-cells = <0>;

    eth1: enc28j60@0 {
        compatible = "microchip,enc28j60";
        reg = <0>;  /* for spi, this defines the chipselect */
        /**
         * gpio_int has interrupts-cells = <2>
         *
         * How does this distinguish between e.g. GPIOAO_4 on the first chip and GPIOZ_4 on the second ?!
         */
        interrupt-parent = <&gpio_intc>;
        interrupts = <GPIOX_8 IRQ_TYPE_EDGE_FALLING>;

        // causes "enc28j60 spi1.0: there is not valid maps for state default"
        pinctrl-0 = <&enc28j60_int_pin>;
        pinctrl-names = "default";

        spi-max-frequency = <12000000>;
        status = "okay";
        debug = <1>;
    };
};

// See meson-g12-common.dtsi
// I think what happens here is that we define this pin as the interrupt pin (something must
// tell the chip that we want this pin to receive interrupts) and then "interrupts" in &eth1
// actually uses it
&periphs_pinctrl {
    enc28j60_int_pin: enc28j60_int_pin@0 {
        amlogic,pins = <&gpio GPIOX_8>;
        amlogic,function = <0>; /* in */
        amlogic,pull = <IRQ_TYPE_NONE>;
    };
};

// Not entirely sure this is correct, but I haven't found any other way to do this
// and this compiles
/ {
    __overrides__ {
        irq   = <&eth1>, "interrupts:0", <&enc28j60_int_pin>, "brcm,pins:0";
        speed = <&eth1>, "spi-max-frequency:0";
    };
};

不幸的是，我努力的结果仍然是一个无法运行的 enc28j60 驱动程序：

[    3.882872] enc28j60 spi1.0: there is not valid maps for state default
[    3.884022] enc28j60 spi1.0: Ethernet driver 1.02 loaded
[    3.896540] enc28j60 spi1.0: chip not found
[    3.896686] enc28j60: probe of spi1.0 failed with error -5

我已经记录了整个过程并且Radxa 的​​进展（或缺乏）社区论坛。

我需要取得进展的是信息（但我很乐意接受所有问题的答案；））：

1. 如何将内核和驱动程序置于调试模式，以便我可以看到 比上面输出的 dmesg 更详细的信息。
2. 如何验证我尝试使用中断引脚执行的操作是否正确 并有意义。 （我在其他平台找到了类似的例子 [tegra, brcm]，但对于介子芯片，pinctrl 似乎是 完全作为内核驱动程序代码的一部分完成，而不是作为设备 树）。