26 设备树里mcp2515的描述

mcp2515工作原理及使用spi_board_info描述设备的方式请参考:http://blog.youkuaiyun.com/jklinux/article/details/74347820

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mcp2515设备驱动在内核里的配置:

make menuconfig ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-

[*] Networking support  --->
   <*>   CAN bus subsystem support  --->
    CAN Device Drivers  ---> 
        <*> Platform CAN drivers with Netlink support 
        [*]   CAN bit-timing calculation
            CAN SPI interfaces  --->
             <*> Microchip MCP251x SPI CAN controllers

保存退出后重编并更新内核镜像.

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设备树里mcp2515设备节点的描述:
//连接在spi1控制器, 模块的int脚接PA12

&spi1 {
    #address-cells = <1>;
    #size-cells = <0>;

    status = "okay";
    pinctrl-names = "default";
    pinctrl-0 = <&spi1_pins &spi1_cs_pins>;
    cs-gpios = <&pio 0 13 GPIO_ACTIVE_HIGH>;

    myspidev {
        compatible = "microchip,mcp2515";
        reg = <0>;
        clocks = <&osc24M>;
        status = "okay";
        spi-max-frequency = <5000000>;

        interrupt-parent = <&pio>;
        interrupts = <0  12  IRQ_TYPE_EDGE_FALLING>;

        vdd-supply = <&reg_vcc3v3>;
        xceiver-supply = <&reg_vcc3v3>;
    };  
};

驱动好后，可通过”ifconfig -a”查看到有can0设备.