stmmac: support wake up irq from external sources (v3)

On some platforms e.g. SPEAr the wake up irq differs from the
GMAC interrupt source.
With this patch an external wake up irq can be passed through the
platform code and named as "eth_wake_irq".

In case the wake up interrupt is not passed from the platform
so the driver will continue to use the mac irq (ndev->irq)
Signed-off-by: Deepak Sikri <deepak.sikri@st.com>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/stmmac.h

@@ -72,6 +72,7 @@ struct stmmac_priv {
 	spinlock_t lock;
 	int wolopts;
 	int wolenabled;
+	int wol_irq;
 #ifdef CONFIG_STMMAC_TIMER
 	struct stmmac_timer *tm;
 #endif

drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c

@@ -321,10 +321,10 @@ static int stmmac_set_wol(struct net_device *dev, struct ethtool_wolinfo *wol)
 	if (wol->wolopts) {
 		pr_info("stmmac: wakeup enable\n");
 		device_set_wakeup_enable(priv->device, 1);
-		enable_irq_wake(dev->irq);
+		enable_irq_wake(priv->wol_irq);
 	} else {
 		device_set_wakeup_enable(priv->device, 0);
-		disable_irq_wake(dev->irq);
+		disable_irq_wake(priv->wol_irq);
 	}
 
 	spin_lock_irq(&priv->lock);

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -1515,7 +1515,7 @@ static int stmmac_mac_device_setup(struct net_device *dev)
 
 	if (device_can_wakeup(priv->device)) {
 		priv->wolopts = WAKE_MAGIC; /* Magic Frame as default */
-		enable_irq_wake(dev->irq);
+		enable_irq_wake(priv->wol_irq);
 	}
 
 	return 0;
@@ -1588,6 +1588,18 @@ static int stmmac_dvr_probe(struct platform_device *pdev)
 		pr_info("\tPMT module supported\n");
 		device_set_wakeup_capable(&pdev->dev, 1);
 	}
+	/*
+	 * On some platforms e.g. SPEAr the wake up irq differs from the mac irq
+	 * The external wake up irq can be passed through the platform code
+	 * named as "eth_wake_irq"
+	 *
+	 * In case the wake up interrupt is not passed from the platform
+	 * so the driver will continue to use the mac irq (ndev->irq)
+	 */
+	priv->wol_irq = platform_get_irq_byname(pdev, "eth_wake_irq");
+	if (priv->wol_irq == -ENXIO)
+		priv->wol_irq = ndev->irq;
+
 
 	platform_set_drvdata(pdev, ndev);