3568 Android otg模式下adb热拔插不识别
- 作者：吴思含（Witheart）
- 更新时间：20250703
问题背景
- AM3568客户反馈有线adb连接不稳定，开机前接入USB后，可识别到adb，但在开机后热拔插，则识别不到
问题原因
-
otg模式下，otg的USB接口不能带电，必须由主机供电，才能进行热拔插的检测。
-
硬件原理图上可以发现，该otg口的VCC是由gs7615这个电子开关控制的
-
查看代码可以发现，设备树中首先定义了控制电子开关的引脚，然后在设备树解析时将这个引脚默认拉高，导致引脚在开机后就一直为高电平，无法进行热拔插检测
kernel/arch/arm64/boot/dts/rockchip/NK_RK3568.dtsi
dtsi
nk_io_init {
compatible = "nk_io_control";
//hw-hub c3568a
V_USBHOST_EN1 = <&gpio3 RK_PA2 GPIO_ACTIVE_HIGH>;
pinctrl-0 = <&nk_io_gpio>;
};kernel/drivers/gpio/nk_io_core.c
c
static int nk_io_control_probe(struct platform_device *pdev)
{
...
unsigned int USBHUB_RST_1;
//hub
ret = of_get_named_gpio_flags(node, "V_USBHOST_EN1", 0, &flags);
if (ret < 0) {
printk("%s() Can not read property V_USBHOST_EN1\n", __FUNCTION__);
goto err;
} else {
pdata->V_USBHOST_EN1 = ret;
ret = devm_gpio_request(&pdev->dev, pdata->V_USBHOST_EN1, "V_USBHOST_EN1");
if(ret < 0){
printk("%s() devm_gpio_request V_USBHOST_EN1 request ERROR\n", __FUNCTION__);
goto err;
}
ret = gpio_direction_output(pdata->V_USBHOST_EN1,1);
if(ret < 0){
printk("%s() gpio_direction_input V_USBHOST_EN1 set ERROR\n", __FUNCTION__);
goto err;
}
}
...
}解决方式
原有代码
- 系统下，原来就有一个otg模式的开关，只需要在开启otg模式时，控制V_USBHOST_EN1断开USB口的供电，在关闭otg模式时恢复供电即可。这样在otg模式开启时，usb口由主机供电，便可以热拔插检测adb。
原有代码：
system/core/ril/main.c
diff
diff --git a/system/core/ril/main.c b/system/core/ril/main.c
index 3a40c9d614..f85847fbc8 100755
--- a/system/core/ril/main.c
+++ b/system/core/ril/main.c
@@ -520,6 +520,46 @@ exit:
}
#endif
+//add other
+static void* pthread_func1 (void* data){
+ char fileBuf[100];
+ int size;
+ char buf[512]="\0";
+
+ while (1)
+ {
+ sleep(60);
+
+ size = readfile("/sys/devices/platform/ff770000.syscon/ff770000.syscon:usb2-phy@e450/otg_mode", (unsigned char*)fileBuf, sizeof(fileBuf));
+ ALOGI("persist.usb3.otg.mode init=%d \n", size);
+
+ if(property_get("persist.usb3.otg.mode",buf, NULL) > 0)
+ {
+ //host
+ if(strncmp(buf, "0", strlen("0")) == 0)
+ {
+ if(strncmp(fileBuf, "host", strlen("host")) != 0)
+ {
+ ALOGI("persist.usb3.otg.mode 0=host \n");
+ system("echo host > /sys/devices/platform/ff770000.syscon/ff770000.syscon:usb2-phy@e450/otg_mode");
+ }
+ }
+
+ //otg
+ if(strncmp(buf, "1", strlen("1")) == 0)
+ {
+ if(strncmp(fileBuf, "otg", strlen("otg")) != 0)
+ {
+ ALOGI("persist.usb3.otg.mode 1=otg \n");
+ system("echo otg > /sys/devices/platform/ff770000.syscon/ff770000.syscon:usb2-phy@e450/otg_mode");
+ }
+ }
+ }
+ }
+
+ return NULL;
+}
+
static void* pthread_func (void* data){
int ret = 0;
int stateSim = 0;
@@ -642,9 +682,10 @@ int main(int argc, char** argv){
int ret = 0, ret2 = 0;
ret = pthread_create(&pt_thread, NULL, pthread_func, NULL);
+ ret2 = pthread_create(&pt_thread2, NULL, pthread_func1, NULL);
pthread_join (pt_thread, NULL);
-
+ pthread_join (pt_thread2, NULL);
return 0;
#if 0新增代码
- 加入修改7eaedb38970cdd7b8e517d9aef22895105637c55(fix(otg): 开机后adb无法热拔插识别问题)
- 注意，原来的io初始化逻辑是在
kernel/drivers/gpio/nk_io_core.c中做的（内核空间），而新增的控制逻辑是在system/core/ril/main.c中做的（用户空间）。 - 需要取消在内核空间的初始化，才能在用户空间导出该gpio，否则操作无法成功
- 具体修改如下：
diff
➜ rk3568_rk_android11.0_sdk git:(AM-3568-S-L19201080_H-01) ✗ git --no-pager diff be1e387e07e7df54a7c060d3e07142c8a2a76f0f 7eaedb38970cdd7b8e517d9aef22895105637c55
diff --git a/kernel/arch/arm64/boot/dts/rockchip/NK_RK3568.dtsi b/kernel/arch/arm64/boot/dts/rockchip/NK_RK3568.dtsi
index cc615d9cc6..f36000ccde 100644
--- a/kernel/arch/arm64/boot/dts/rockchip/NK_RK3568.dtsi
+++ b/kernel/arch/arm64/boot/dts/rockchip/NK_RK3568.dtsi
@@ -123,7 +123,7 @@
//USB_EN_OC_GPIO0_A5 = <&gpio0 RK_PA5 GPIO_ACTIVE_HIGH>;
//hw-hub c3568a
- V_USBHOST_EN1 = <&gpio3 RK_PA2 GPIO_ACTIVE_HIGH>;
+ // V_USBHOST_EN1 = <&gpio3 RK_PA2 GPIO_ACTIVE_HIGH>;
//V_USBHOST_EN2 = <&gpio3 RK_PA3 GPIO_ACTIVE_HIGH>;
USBHUB_RST_1 = <&gpio3 RK_PA4 GPIO_ACTIVE_HIGH>;
diff --git a/kernel/drivers/gpio/nk_io_core.c b/kernel/drivers/gpio/nk_io_core.c
index 5b05fb8c3a..83da3c60c5 100755
--- a/kernel/drivers/gpio/nk_io_core.c
+++ b/kernel/drivers/gpio/nk_io_core.c
@@ -233,7 +233,7 @@ static int nk_io_control_probe(struct platform_device *pdev)
unsigned int USBHUB_RST_2;
unsigned int USBHUB_RST_3;
-
+#if 0 //改为用户空间控制system/core/ril/main.c
//hub
ret = of_get_named_gpio_flags(node, "V_USBHOST_EN1", 0, &flags);
if (ret < 0) {
@@ -253,7 +253,8 @@ static int nk_io_control_probe(struct platform_device *pdev)
goto err;
}
}
-
+#endif
+
#if 0
ret = of_get_named_gpio_flags(node, "V_USBHOST_EN2", 0, &flags);
if (ret < 0) {
diff --git a/system/core/ril/main.c b/system/core/ril/main.c
index 7a30c7e87e..7dd4cdd7cf 100755
--- a/system/core/ril/main.c
+++ b/system/core/ril/main.c
@@ -541,6 +541,34 @@ static void* pthread_func1 (void* data){
char fileBuf[100];
int size;
char buf[512]="\0";
+
+ // 初始化日志标签
+ const char* TAG = "USB_OTG";
+ static bool gpio_initialized = false;
+
+ // ===== GPIO 初始化 =====
+ if (!gpio_initialized) {
+ // 导出 GPIO
+ if (system("echo 98 > /sys/class/gpio/export") == 0) {
+ ALOGI("[%s] GPIO98 exported successfully", TAG);
+ } else {
+ ALOGW("[%s] GPIO98 may already be exported (ignorable)", TAG);
+ }
+
+ // 设置方向
+ if (system("echo out > /sys/class/gpio/gpio98/direction") == 0) {
+ ALOGI("[%s] GPIO direction set to output", TAG);
+ } else {
+ ALOGE("[%s] Failed to set GPIO direction! Error: %d", TAG, errno);
+ }
+
+ // 设置初始值（默认关闭OTG）
+ system("echo 1 > /sys/class/gpio/gpio98/value");
+ ALOGI("[%s] GPIO98 initialized to HIGH (OTG disabled by default)", TAG);
+
+ gpio_initialized = true;
+ }
+
while (1)
{
@@ -552,6 +580,16 @@ static void* pthread_func1 (void* data){
if(property_get("persist.usb3.otg.mode",buf, NULL) > 0)
{
+ // ===== 新增的GPIO控制逻辑 =====
+ if(strncmp(buf, "0", 1) == 0) { // Host模式
+ ALOGI("[%s] OTG disabled (Host mode)", TAG);
+ system("echo 1 > /sys/class/gpio/gpio98/value");
+
+ } else if(strncmp(buf, "1", 1) == 0) { // OTG模式
+ ALOGI("[%s] OTG enabled (OTG mode)", TAG);
+ system("echo 0 > /sys/class/gpio/gpio98/value");
+ }
+
//host
if(strncmp(buf, "0", strlen("0")) == 0)
{