不啰嗦，上设备树代码：

spi {
                compatible = "spi-gpio";
                #address-cells = <0x1>;
                //ranges;
                #size-cells = <0>;
                gpio-sck = <&gpio2 18 0>;
                gpio-miso = <&gpio2 17 0>;
                gpio-mosi = <&gpio2 1 0>;
                cs-gpios = <&gpio7 12 0>;
                num-chipselects = <1>;

                /* clients */
                can0: can@1 {
                        compatible = "microchip,mcp2515";
                        reg = <0>;
                        //clocks = <&clks 24>;
                        clocks = <&clk16m>;
                        interrupt-parent = <&gpio1>;
                        interrupts = <30 0x2>;
                        spi-max-frequency = <10000000>;
                        status = "okay";
                        //vdd-supply = <&reg5v0>;
                        //xceiver-supply = <&reg5v0>;
                };

        };

内核设备树文档内容为：

SPI-GPIO devicetree bindings

Required properties:

 - compatible: should be set to "spi-gpio"
 - #address-cells: should be set to <0x1>
 - ranges
 - gpio-sck: GPIO spec for the SCK line to use
 - gpio-miso: GPIO spec for the MISO line to use
 - gpio-mosi: GPIO spec for the MOSI line to use
 - cs-gpios: GPIOs to use for chipselect lines.
             Not needed if num-chipselects = <0>.
 - num-chipselects: Number of chipselect lines. Should be <0> if a single device
                    with no chip select is connected.

Example:

    spi {
        compatible = "spi-gpio";
        #address-cells = <0x1>;
        ranges;

        gpio-sck = <&gpio 95 0>;
        gpio-miso = <&gpio 98 0>;
        gpio-mosi = <&gpio 97 0>;
        cs-gpios = <&gpio 125 0>;
        num-chipselects = <1>;

        /* clients */
    };

注释了ranges;选项，并没了解深层次原因，待补充，我也是参考设备树里面别的厂家写的代码改的，慢慢再深入吧。 
然后，配置内核，选上spi-gpio驱动选项即可。 
mcp2510驱动类似，主要是clocks这一项不会写，还是参考了别人写的，添加了一个时钟，成功运行。

clocks {
       /* Fixed crystal dedicated to mcp251x */
       clk16m: clk@1 {
                compatible = "fixed-clock";
                reg = <1>;
                #clock-cells = <0>;
                clock-frequency = <16000000>;
                clock-output-names = "clk16m";
       };
    };