Column types are truncated when mapping PostGIS types

$em = $this->container->get('doctrine.orm.default_entity_manager');
$conn = $em->getConnection();
if (!Type::hasType('point')) {
  Type::addType('point', 'Demo\GeoBundle\Lib\Type\PointType');
  $conn->getDatabasePlatform()->registerDoctrineTypeMapping('point', 'point');
}

<?php

namespace Demo\GeoBundle\Lib\Type;

use Demo\GeoBundle\Lib\Point;

use Doctrine\DBAL\Types\Type; 
use Doctrine\DBAL\Platforms\AbstractPlatform;

class PointType extends Type {

  const POINT = 'point';

  /**
   *
   * @param array $fieldDeclaration
   * @param AbstractPlatform $platform
   * @return string 
   */
  public function getSqlDeclaration(array $fieldDeclaration, AbstractPlatform $platform)
  {
    return 'geography(POINT,'.Point::$SRID.')';
  }

  /**
   *
   * @param type $value
   * @param AbstractPlatform $platform
   * @return Point 
   */
  public function convertToPHPValue($value, AbstractPlatform $platform)
  {
    return Point::fromGeoJson($value);
  }

  public function getName()
  {
    return self::POINT;
    //return 'geography(POINT,'.Point::$SRID.')';
  }

  public function convertToDatabaseValue($value, AbstractPlatform $platform)
  {
    return $value->toWKT();
  }

  public function canRequireSQLConversion()
  {
    return true;
  }

  public function convertToPHPValueSQL($sqlExpr, $platform)
  {
    return 'ST_AsGeoJSON('.$sqlExpr.') ';
  }

  public function convertToDatabaseValueSQL($sqlExpr, AbstractPlatform $platform)
  {
    return $sqlExpr;
  }

}

?>

<?php

namespace Demo\GeoBundle\Lib;

use Demo\GeoBundle\Lib\GeoException;

class Point {
  private $lat;
  private $lon;
  public static $SRID = '4326';

  private function __construct($lon, $lat) {
    $this->lat = $lat;
    $this->lon = $lon;
  }
  
  public function setLongitude($lon) {
    $this->lon = $lon;
  }
  
  public function getLongitude() {
    return $this->lon;
  }

  public function setLatitude($lat) {
    $this->lat = $lat;
  }

  public function getLatitude() {
    return $this->lat;
  }

  public function toGeoJson(){
    $array = array("type" => "Point", "coordinates" => array ($this->lon, $this->lat));
    return \json_encode($array);
  }

  /**
   *
   * @return string 
   */
  public function toWKT() {
    return 'SRID='.self::$SRID.';POINT('.$this->lon.' '.$this->lat.')';
  }

  /**
   *
   * @param string $geojson
   * @return Point 
   */
  public static function fromGeoJson($geojson) 
  {
    $a = json_decode($geojson);
    //check if the geojson string is correct
    if ($a == null or !isset($a->type) or !isset($a->coordinates)){
      throw GeoException::badJsonString();
    }

    if ($a->type != "Point"){
      throw GeoException::badGeoType();
    } else {
      $lon = $a->coordinates[0];
      $lat = $a->coordinates[1];
      return Point::fromLonLat($lon, $lat);
    }

  }
  
  /**
   *
   * @return string
   */
  public function __toString() {
    return $this->lon . ' ' . $this->lat;
  }

  /**
   *
   * @return array
   */
  public function toArray() {
    return array($this->lon, $this->lat);
  }

  public static function fromLonLat($lon, $lat)
  {
    if (($lon > -180.0 && $lon < 180.0) && ($lat > -90.0 && $lat < 90.0))
    {
      return new Point($lon, $lat);
    } else {
      throw GeoException::badCoordinates($lon, $lat);
    }
  }
}

?>

<?php

namespace Demo\GeoBundle\Lib;

class GeoException extends \RuntimeException
{
    public function __construct($message = null, \Exception $previous = null, $code = 0)
    {
        parent::__construct($message, $code, $previous);
    }

    public static function badJSonString()
    {
      return new GeoException("Bad JSon string");
    }

    public static function badGeoType()
    {
      return new GeoException("Bad geo type");
    }

    public static function badCoordinates($lon, $lat)
    {
      return new GeoException("Bad coordinates: " . $lon . " " . $lat);
    }
}

<?php

namespace Demo\TestBundle\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity
 * @ORM\Table(name="test_points")
 */
class TestPoint
{
  /**
   * @ORM\Id
   * @ORM\Column(type="integer")
   * @ORM\GeneratedValue(strategy="AUTO")
   */
  protected $id;

  /**
   * @ORM\Column(type="point")
   */
  protected $coordinates;

  /**
   * Get id
   *
   * @return integer 
   */
  public function getId()
  {
    return $this->id;
  }

  /**
   * Set coordinates
   *
   * @param point $coordinates
   * @return Partner
   */
  public function setCoordinates($coordinates)
  {
    $this->coordinates = $coordinates;
    return $this;
  }

  /**
   * Get coordinates
   *
   * @return point 
   */
  public function getCoordinates()
  {
    return $this->coordinates;
  }
  
  public function setLongitude($lon)
  {
    if ($this->coordinates == null)
    {
      $this->coordinates = Point::fromLonLat($lon, 0);
    }
    else
    {
      $this->coordinates->setLongitude($lon);
    }
  }
  
  public function getLongitude()
  {
    return $this->coordinates == null ? 0 : $this->coordinates->getLongitude();
  }
  
  public function setLatitude($lat)
  {
    if ($this->coordinates == null)
    {
      $this->coordinates = Point::fromLonLat(0, $lat);
    }
    else
    {
      $this->coordinates->setLatitude($lat);
    }
  }
  
  public function getLatitude()
  {
    return $this->coordinates == null ? 0 : $this->coordinates->getLatitude();
  }
}