How do I get the discount price for promo code or gift card?

I am trying to get the discount that is being calculated in the cart. I can get the coupon code with this: Mage::getSingleton('checkout/cart')->getQuote()->getC开发者_如何学运维ouponCode(); But I have yet to figure out how to get the amount that is discounted from the coupon code.

  // get coupon amount 
   $quote = Mage::getSingleton('checkout/session')->getQuote();

    foreach ($quote->getAllItems() as $item){

    echo $item->getDiscountAmount();

    } 
   // get giftcard amount
   $giftcard = $quote->getGiftCardsAmountUsed();