系统自带GPIO控制驱动: 内核已经自带了通用GPIO驱动,可以直接在用户空间操作. 路径: /sys/class/gpio root@rk3288:/sys/class/gpio # ls export gpiochip0 gpiochip120 gpiochip152 gpiochip184 gpiochip216 gpiochip24 gpiochip248 gpiochip280 gpiochip56 gpiochip88 unexport 比如我要操作GPIO8_A6作为高电平输出有效, 那么有以下问题: 1. 对应的gpio number是多少呢? 2. 如何设置成输出 3. 如何输出高电平 问题1: 可以通过/sys/kernel/debug/gpio查询信息: root@rk3288:/sys/kernel/debug # cat gpio                                        //snip GPIOs 184-215, platform/ff770000.pinctrl, gpio6:  gpio-193 (?                   ) in  hi  gpio-194 (?                   ) in  hi GPIOs 216-247, platform/ff770000.pinctrl, gpio7:  gpio-218 (enable              ) out hi  gpio-219 (lcd_en              ) in  hi  gpio-220 (lcd_cs              ) in  hi  gpio-221 (gslX680 wake pin    ) out hi  gpio-222 (gslX680 irq pin     ) out lo  gpio-223 (headset_gpio        ) in  hi  gpio-233 (?                   ) in  hi  gpio-234 (?                   ) in  hi GPIOs 248-279, platform/ff770000.pinctrl, gpio8: GPIOs 280-311, platform/ff770000.pinctrl, gpio15: 可以看到gpio8是以nubmer为248开始, 那么GPIO8_A6就是 248(32*8) +6(0*8+6)　 = 254

接下来就可以导出gpio了root@rk3288:/sys/class/gpio # echo 254 > export                          root@rk3288:/sys/class/gpio # ls export gpio254 ...... 问题2root@rk3288:/sys/class/gpio/gpio254 # echo out > direction                      root@rk3288:/sys/class/gpio/gpio254 # cat direction                             out 问题3:root@rk3288:/sys/class/gpio/gpio254 # echo 1 > value                            root@rk3288:/sys/class/gpio/gpio254 # cat value                                 1解决方法: init.rc [kris@:~/rk3288/device/rockchip/common/recovery/etc]$ g df diff --git a/recovery/etc/init.rc b/recovery/etc/init.rc index efe2a5d..75d7554 100755 --- a/recovery/etc/init.rc +++ b/recovery/etc/init.rc @@ -85,6 +85,12 @@ on late-init  on property:sys.powerctl=*     powerctl ${sys.powerctl}   +#Kris, 170407, GPIO8_A6 -> gpio254, used to inform sd upgrade complete. +on property:sdupgrade.complete=true+       write /sys/class/gpio/export 254 +       write /sys/class/gpio/gpio254/direction out +       write /sys/class/gpio/gpio254/value 1 +  service ueventd /sbin/ueventd      critical      seclabel u:r:ueventd:s0 recovery.cpp [kris@:~/rk3288/bootable/recovery]$ g df diff --git a/recovery.cpp b/recovery.cpp index 8299672..a0edc15 100755 --- a/recovery.cpp +++ b/recovery.cpp @@ -2285,6 +2285,10 @@ HANDLE_STATUS :          strcat(kernellogPath, "/kernel.txt");          save_kernel_log(kernellogPath);          #endif + +       //Kris, 170407, light led on after sd upgrade complete. +       property_set("sdupgrade.complete", "true"); +                 if (bSDMounted)              checkSDRemoved();

内核C语言代码

#include  

 gpio_request(84,"red_led"); //red led  向CPU请求GPIO  gpio_request(85,"green_led"); //green led 向CPU请求GPIO  gpio_direction_output(84, 1);  //close red led  输出GPIO84高电平  gpio_direction_output(85, 0);  //open green led  输出GPIO85低电平

Uboot 写法

 gpio_direction_output(GPIO_BANK2 | GPIO_C4, 1); //red led  gpio_direction_output(GPIO_BANK2 | GPIO_C5, 1); //green led  

freamwork 写法控制

diff --git a/services/core/java/com/android/server/power/PowerManagerService.java b/services/core/java/com/android/se index 348af1f..13b87c5f 100755 --- a/services/core/java/com/android/server/power/PowerManagerService.java +++ b/services/core/java/com/android/server/power/PowerManagerService.java @@ -94,7 +94,14 @@ import static android.os.PowerManagerInternal.WAKEFULNESS_DREAMING;  import android.hardware.hdmi.*;  import android.os.ServiceManager;   - +import java.io.BufferedReader; +import java.io.File; +import java.io.FileDescriptor; +import java.io.FileReader; +import java.io.IOException; +import java.io.PrintWriter; +import java.io.RandomAccessFile; +import java.io.FileOutputStream;  /**   * The power manager service is responsible for coordinating power management   * functions on the device. @@ -526,7 +533,59 @@ public final class PowerManagerService extends SystemService      private static native void nativeSetAutoSuspend(boolean enable);      private static native void nativeSendPowerHint(int hintId, int data);      private static native void nativeSetFeature(int featureId, int data); - +        //add by hason +public  void Led_On_Off_my(int i, String led) +     {    // String led0="0"; +          // String led1="1" +             //if (levle==true)i=1; +          File file = new File("/sys/class/leds/red/brightness"); +          File file1 = new File("/sys/class/leds/green/brightness"); +           if(i==1) +           { +           if (file.exists()) +              { +                try{ +                if (file.canWrite()) +                   {     Slog.d("lhm-write", file.toString() + "   can  write"); +                        FileOutputStream fout = new FileOutputStream(file); +                       byte[]  bytes =led.getBytes(); +                         fout.write(bytes); + +                        fout.close(); +                   } +                   else +                  Slog.d("lhm", file.toString() + "   can not write"); +                }catch(Exception e) +                { +                        Slog.d("hjc", file.toString() + "can not write"); +                } +              } +         } + +        else + + { +           if (file1.exists()) +              { +                try{ +                if (file1.canWrite()) +                   {     Slog.d("lhm-write", file1.toString() + "   can  write"); +                        FileOutputStream fout = new FileOutputStream(file1); +                       byte[]  bytes =led.getBytes(); +                         fout.write(bytes); + +                        fout.close(); +                   } +                   else +                  Slog.d("lhm", file1.toString() + "   can not write"); +                }catch(Exception e) +                { +                        Slog.d("hjc", file1.toString() + "can not write"); +                } +              } +         } +        } +//end      public PowerManagerService(Context context) {          super(context);          mContext = context; @@ -1241,6 +1300,10 @@ public final class PowerManagerService extends SystemService          try {              switch (mWakefulness) {                  case WAKEFULNESS_ASLEEP: +                                        Led_On_Off_my(2,"1"); +                  Slog.i(TAG, "LED GREEN ON"); +                    Led_On_Off_my(1,"1"); +                  Slog.i(TAG, "LED RED OFF");                      Slog.i(TAG, "Waking up from sleep (uid " + reasonUid +")...");                      break;                  case WAKEFULNESS_DREAMING: @@ -1317,6 +1380,10 @@ public final class PowerManagerService extends SystemService                      Slog.i(TAG, "Going to sleep due to lid switch (uid " + uid +")...");                      break;                  case PowerManager.GO_TO_SLEEP_REASON_POWER_BUTTON: +                        Led_On_Off_my(1,"0"); +                  Slog.i(TAG, "LED RED ON"); +                    Led_On_Off_my(2,"0"); +                  Slog.i(TAG, "LED GREEN OFF");                      Slog.i(TAG, "Going to sleep due to power button (uid " + uid +")...");                      break;                  case PowerManager.GO_TO_SLEEP_REASON_SLEEP_BUTTON: (END)