Add error handling for GPIO in SPIDEV

utility/SPIDEV/gpio.cpp

@@ -47,9 +47,11 @@ void GPIO::Gopen(int port, int DDR)
 
   fd = open(dev_name, O_RDONLY);
   if (fd >= 0){
-
+    close(fd);
+  }else{
+    throw GPIOException("Can't open device");
   }
-  close(fd);
+
     #if !defined NEWGPIO
 
 
@@ -134,8 +136,16 @@ int GPIO::Gread(int port)
       rq.flags = GPIOHANDLE_REQUEST_INPUT;
       rq.lines = 1;
       ret = ioctl(fd, GPIO_GET_LINEHANDLE_IOCTL, &rq);
+      if(ret == -1){
+        throw GPIOException("Can't get line handle from IOCTL");
+        return ret;
+      }
       close(fd);
       ret = ioctl(rq.fd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, &data);
+      if(ret == -1){
+        throw GPIOException("Can't get line value from IOCTL");
+        return ret;
+      }    
       close(rq.fd);
       return ret;      
     }
@@ -189,13 +199,25 @@ void GPIO::Gwrite(int port, int value)
     struct gpiohandle_data data;
     int fd, ret;
     fd = open(dev_name, O_RDONLY);
+    if(fd < 0){
+      throw GPIOException("Can't open dev");
+      return;
+    }
     rq.lineoffsets[0] = port;
     rq.flags = GPIOHANDLE_REQUEST_OUTPUT;
     rq.lines = 1;
     ret = ioctl(fd, GPIO_GET_LINEHANDLE_IOCTL, &rq);
+    if(ret == -1){
+      throw GPIOException("Can't get line handle from IOCTL");
+      return;
+    }
     close(fd);
     data.values[0] = value;
     ret = ioctl(rq.fd, GPIOHANDLE_SET_LINE_VALUES_IOCTL, &data);
+    if(ret == -1){
+      throw GPIOException("Can't set line value from IOCTL");
+      return;
+    }
     close(rq.fd);
 
     #if !defined NEWGPIO