Hardware detection for gpio pin

examples/basic.php

@@ -18,13 +18,14 @@ $gpio->setMapper( new WiringPiMapper(2) );
 // be the actual GPIO0 pin. 
 $led = $gpio[0]
     ->export()
-    ->setDirection("output")
+    ->setEdge(Gpio::EDGE_NONE)
-    ->setValue(0)
+    ->setDirection(Gpio::DIR_OUT)
-    ->dumpStatus(true);
+    ->setLabel("LED pin")
+    ->setValue(0);
 
 $x = 0;
 while(true) {
     $x = (int)(!$x);
-    $led->setValue($x);
+    $led->setValue($x)->dumpStatus(true);
     usleep(500000);
 }

lib/GpioPin.php

@@ -41,6 +41,8 @@ class GpioPin
     protected $edge;
     
     protected $handler;
+    
+    protected $hardware;
 
     protected $label;
     
@@ -51,7 +53,25 @@ class GpioPin
         $this->pin = (int)$pin;
         $this->gpio = $gpio;
         $this->export();
-        $this->fd = fopen("/sys/class/gpio/gpio{$pin}/value", "rb");
+        $this->hardware = $this->findHardware();
+    }
+    
+    private function findHardware()
+    {
+    	$chips = glob("/sys/class/gpio/gpiochip*");
+    	$pinchip = null;
+    	foreach($chips as $chip) {
+    		$r = null;
+    		if (preg_match("/([0-9]+?)/", $chip, $r)) {
+    			$base = (int)$r[1];
+    			if ($base < $this->pin) { $pinchip = $chip; }
+    		}
+    	}
+    	if ($pinchip) {
+	    	$hw = trim(file_get_contents($pinchip."/label"));
+    		return $hw;
+   		}
+   		return "unknown";
     }
     
     public function __destruct()
@@ -61,17 +81,17 @@ class GpioPin
     
     public function setDirection($direction)
     {
-        if (!in_array($direction, array("input", "output"))) {
+        if (!in_array($direction, array("in", "out"))) {
             throw new \Exception;
         }
         $this->direction = $direction;
-        @file_put_contents("/sys/class/gpio/gpio{$this->pin}/direction", $direction);
+        $this->sysfsWrite($this->pin, "direction", $direction);
         return $this;
     }
     
     public function getDirection()
     {
-        return $this->direction;
+        return $this->sysfsRead($this->pin, "direction");
     }
     
     public function setValue($value)
@@ -83,7 +103,7 @@ class GpioPin
     
     public function getValue()
     {
-        return $this->value;
+        return $this->sysfsRead($this->pin, "value");
     }
 
     /**
@@ -110,6 +130,9 @@ class GpioPin
     
     public function export()
     {
+        if (file_exists("/sys/class/gpio/gpio{$this->pin}")) {
+        	return $this;
+        }
         $this->sysfsWrite(null, "export", $this->pin);
         if (!file_exists("/sys/class/gpio/gpio{$this->pin}")) {
             throw new HardwareException("Unable to export pin {$this->pin}");
@@ -119,7 +142,7 @@ class GpioPin
     
     public function unexport()
     {
-        @file_put_contents("/sys/class/gpio/unexport", $this->pin);
+    	$this->sysfsWrite(null, "unexport", $this->pin);
         return $this;
     }
     
@@ -150,7 +173,7 @@ class GpioPin
         }
         $ret = fgets($f);
         fclose($f);
-        return $ret;
+        return trim($ret);
     }
     
     public function setEdge($edge)
@@ -202,11 +225,11 @@ class GpioPin
     
     
         foreach(array(    
-            "Direction" => $direction,
+            "Direction" => $this->getDirection(),
-            "Value" => ($this->value?1:0),
+            "Value" => ($this->getValue()?1:0),
-            "Edge" => $edge,
+            "Edge" => $this->getEdge(),
             "Label" => $this->label,
-            "Hardware" => "unknown",
+            "Hardware" => $this->hardware,
             "Int count" => 0
         ) as $k=>$v) {
             if ($ansi) {