CPU：RK3399
系统：Android 7.1.2
为了降低成本，主板将 Type-C 改为 MicroUSB 接口，节省了 fusb302芯片
参考 Rockchip 的官方文档第4部分：Micro USB2.0 OTG DTS配置
RKDocs/common/usb/Rockchip-Developer-Guide-Linux4.4-RK3399-USB-DTS-CN.pdf
&tcphy0 { status = "disabled"; }; &u2phy0 { status = "okay"; /* Micro USB2 PHY 删除了extcon属性 */ otg-vbus-gpios = <&gpio3 RK_PC6 GPIO_ACTIVE_HIGH>; /* Vbus GPIO配置 */ u2phy0_otg: otg-port { /* 文档中错误写成了u2phy1_otg */ status = "okay"; }; ...... }; &usbdrd3_0 { extcon = <&u2phy0>; /* Micro USB3控制器的extcon属性引用u2phy0 */ status = "okay"; }; &usbdrd_dwc3_0 { dr_mode = "otg"; /* Micro USB3控制器的dr_mode配置为otg */ maximum-speed = "high-speed"; /* maximum-speed 属性配置为high-speed */ phys = <&u2phy0_otg>; /* phys 属性只引用USB2 PHY节点 */ phy-names = "usb2-phy"; status = "okay"; };
按照文档中说明，修改这部分就可以了，但是编译内核部分烧录后，不能进安卓系统，串口一直循环打印如下：
[ 9.878630] init: Starting service 'surfaceflinger'... [ 10.294620] init: Service 'surfaceflinger' (pid 532) killed by signal 6 [ 10.294664] init: Service 'surfaceflinger' (pid 532) killing any children in process group [ 10.294709] init: Service 'zygote' is being killed... [ 10.356365] init: Service 'zygote' (pid 254) killed by signal 9 [ 10.356441] init: Service 'zygote' (pid 254) killing any children in process group [ 10.356634] init: write_file: Unable to open '/sys/android_power/request_state': No such file or directory [ 10.356778] init: write_file: Unable to write to '/sys/power/state': Invalid argument [ 10.356805] init: Service 'audioserver' is being killed... [ 10.357239] init: Service 'cameraserver' is being killed... [ 10.357327] init: Service 'media' is being killed... [ 10.357454] init: Service 'netd' is being killed... [ 10.358943] init: Starting service 'zygote'... [ 10.364342] init: Service 'audioserver' (pid 299) killed by signal 9 [ 10.364427] init: Service 'audioserver' (pid 299) killing any children in process group [ 10.365879] init: Starting service 'audioserver'... [ 10.369573] init: Service 'netd' (pid 310) killed by signal 9 [ 10.369677] init: Service 'netd' (pid 310) killing any children in process group [ 10.370582] init: Untracked pid 575 killed by signal 9 [ 10.374127] init: Service 'media' (pid 297) killed by signal 9 [ 10.374192] init: Service 'media' (pid 297) killing any children in process group [ 10.375119] init: Service 'cameraserver' (pid 300) killed by signal 9 [ 10.375158] init: Service 'cameraserver' (pid 300) killing any children in process group [ 10.376450] init: Starting service 'media'... [ 10.378976] init: Starting service 'cameraserver'... [ 10.382610] init: couldn't write 580 to /dev/cpuset/camera-daemon/tasks: No such file or directory [ 12.079202] init: Starting service 'netd'...
开始怀疑是因为没有全部编译的问题，但是全部编译烧录后，还是不能开机，一直提示找不到 drm device，串口一直循环打印如下：
__bionic_open_tzdata: couldn't find any tzdata when looking for GMT! Starting recovery (pid 185) on Fri Jan 18 08:52:30 2013 bootmode = emmc recovery filesystem table ========================= 0 /mnt/internal_sd vfat /dev/block/platform/fe330000.sdhci/by-name/user 0 1 /mnt/external_sd vfat /dev/block/mmcblk0p1 0 2 /system ext4 /dev/block/platform/fe330000.sdhci/by-name/system 0 3 /cache ext4 /dev/block/platform/fe330000.sdhci/by-name/cache 0 4 /metadata ext4 /dev/block/platform/fe330000.sdhci/by-name/metadata 0 5 /data ext4 /dev/block/platform/fe330000.sdhci/by-name/userdata 0 6 /cust ext4 /dev/block/platform/fe330000.sdhci/by-name/cust 0 7 /custom ext4 /dev/block/platform/fe330000.sdhci/by-name/custom 0 8 /misc emmc /dev/block/platform/fe330000.sdhci/by-name/misc 0 9 /uboot emmc /dev/block/platform/fe330000.sdhci/by-name/uboot 0 10 /charge emmc /dev/block/platform/fe330000.sdhci/by-name/charge 0 11 /resource emmc /dev/block/platform/fe330000.sdhci/by-name/resource 0 12 /parameter emmc /dev/block/platform/fe330000.sdhci/by-name/parameter 0 13 /boot emmc /dev/block/platform/fe330000.sdhci/by-name/boot 0 14 /recovery emmc /dev/block/platform/fe330000.sdhci/by-name/recovery 0 15 /backup emmc /dev/block/platform/fe330000.sdhci/by-name/backup 0 16 /trust emmc /dev/block/platform/fe330000.sdhci/by-name/trust 0 17 /baseparameter emmc /dev/block/platform/fe330000.sdhci/by-name/baseparameter 0 18 /frp emmc /dev/block/platform/fe330000.sdhci/by-name/frp 0 19 /tmp ramdisk ramdisk 0 emmc_point is /dev/block/mmcblk1 sd_point is (null) sd_point_2 is (null) I:InternalSD_ROOT: /mnt/internal_sd I:ExternalSD_ROOT: /mnt/external_sd read cmdline [ 4.309235] fs_mgr: Warning: unknown flag resize I:Boot command: boot-recovery I:Got arguments from boot message [ 4.311229] fs_mgr: Warning: unknown flag resize === start void dumpCmdArgs(int, char **):296 === argv[0] = recovery. argv[1] = --wipe_all. locale is [en_US] stage is [] reason is [(null)] cannot find/open a drm device: No such file or directory cannot open fb0: No such file or directory [ 4.352842] init: Service 'recovery' (pid 185) killed by signal 11 [ 4.352952] init: Service 'recovery' (pid 185) killing any children in process group [ 9.358734] init: Starting service 'recovery'...
查看 dts 文件，里面还有一个地方 &cdn_dp 使用了 fusb0，屏蔽此处即可开机
&cdn_dp { status = "disabled"; extcon = <&fusb0>; phys = <&tcphy0_dp>; };
最后建议把 i2c 中与 fusb302 通讯的部分也 disable 掉，此处不改也没有问题，只是 i2c 不通，但可以正常开机。
fusb0: fusb30x@22 { compatible = "fairchild,fusb302"; reg = <0x22>; pinctrl-names = "default"; pinctrl-0 = <&fusb0_int>; int-n-gpios = <&gpio1 2 GPIO_ACTIVE_HIGH>; vbus-5v-gpios = <&gpio4 26 GPIO_ACTIVE_HIGH>; status = "disabled"; };