海思Hi3559AV100外挂MCP2515实现CAN通信

1. 修改uboot，修改spi4的引脚复用的寄存器

MCP2515挂在SPI4上，中断引脚挂在GPIO4_5上，打开/Hi3559AV100R001C02SPC031CP0002/01.software/board/Hi3559AV100_SDK_V2.0.3.1CP0002/osdrv/opensource/uboot/u-boot-2016.11/board/hisilicon/hi3559av100文件夹下的hi3559av100.c，找到board_init，添加以下内容

int board_init(void)
{
    DECLARE_GLOBAL_DATA_PTR;

    gd->bd->bi_arch_number = MACH_TYPE_HI3559AV100;
    gd->bd->bi_boot_params = CFG_BOOT_PARAMS;

    boot_flag_init();

    writel(0x461, 0x1F0010C8);    //spi4 sclk
    writel(0x461, 0x1F0010CC);   //spi4 sdo
    writel(0x14F1, 0x1F0010D0); //spi4 sdi
    writel(0x461, 0x1F0010D4);   //spi4 csn0
    writel(0x461, 0x1F0010D8);   //spi4 csn1

    return 0;
}

编译uboot

make CROSS_COMPILE=aarch64-himix100-linux- -j 20

make CROSS_COMPILE=aarch64-himix100-linux- u-boot-z.bin