TX2i設備樹SPI驅動

默認/dev下是沒有spi設備的

JetPack版本

JetPack-L4T-3.2.1-linux-x64_b23.run

下載Kernel

sudo git clone http://github.com/jetsonhacks/buildJetsonTX2Kernel.git

git checkout L4T32.2.1   //切換分支

./getKernelSources.sh   //獲取源碼

默認配置內核

cd /usr/src/kernel/kernel-4.4

make tegra18_defconfig

安裝依賴

sudo apt-get install libncurses5-dev

配置內核

make menuconfig

模塊方式加載SPI

編譯內核

cd buildJetsonTX2Kernel

./makeKernel.sh

生成內核模塊

反編譯設備樹

cd /boot/dtb    //目錄下的就是當前模塊使用的設備樹

sudo /usr/src/kernel/kernel-4.4/scripts/dtc/dtc -I dtb -O dts -o myTX2iDeviceTree.dts tegra186-quill-p3489-1000-a00-00-ucm1.dtb

修改設備樹

sudo vim myTX2iDeviceTree.dts

spi@3240000 {
    compatible = "nvidia,tegra186-spi";
    reg = <0x0 0x3240000 0x0 0x10000>;
    ...
    linux,phandle = <0x7d>;
    phandle = <0x7d>;
    spi@0 {
        compatible = "spidev";
        reg = <0x0>;
        spi-max-frequency = <0x1312D00>;
        nvidia,enable-hw-based-cs;
        nvidia,cs-setup-clk-count = <0x1e>;
        nvidia,cs-hold-clk-count = <0x1e>;
        nvidia,rx-clk-tap-delay = <0x1f>;
        nvidia,tx-clk-tap-delau = <0x0>;
    };        
};

從新編譯設備樹
sudo /usr/src/kernel/kernel-4.4/scripts/dtc/dtc -I dts -O dtb -o myTX2iDeviceTree.dtb myTX2iDeviceTree.dts

注：TX2i設備樹反編譯，也看不到設備樹的修改記錄

拷貝設備樹

將myTX2iDeviceTree.dtb放到虛擬機的jetson/64_TX2/Linux_for_Tegr/kernel/dtb目錄下

cp myTX2iDeviceTree.dtb tegra186-quill-p3489-1000-a00-00-ucm1.dtb    //覆蓋原TX2i設備樹文件

開發板進入Recovery模式

按住REC恢復鍵不放，輕點一下RST復位鍵

燒寫設備樹

cd jetson/64_TX2/Linux_for_Tegr

sudo ./flash.sh -r -k kernel-dtb jetson-tx2i mmcblk0p1    //將燒寫tegra186-quill-p3489-1000-a00-00-ucm1.dtb文件

完成