net: fec: add WoL support for i.MX8MQ

By default FEC driver treat irq[0] (i.e. int0 described in dt-binding) as
wakeup interrupt, but this situation changed on i.MX8M serials, SoC
integration guys mix wakeup interrupt signal into int2 interrupt line.
This patch introduces FEC_QUIRK_WAKEUP_FROM_INT2 to indicate int2 as wakeup
interrupt for i.MX8MQ.

Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Link: https://lore.kernel.org/r/20210812070948.25797-1-qiangqing.zhang@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/freescale/fec.h

@@ -492,6 +492,9 @@ struct bufdesc_ex {
  */
 #define FEC_QUIRK_DELAYED_CLKS_SUPPORT	(1 << 21)
 
+/* i.MX8MQ SoC integration mix wakeup interrupt signal into "int2" interrupt line. */
+#define FEC_QUIRK_WAKEUP_FROM_INT2	(1 << 22)
+
 struct bufdesc_prop {
 	int qid;
 	/* Address of Rx and Tx buffers */
@@ -580,6 +583,7 @@ struct fec_enet_private {
 	bool	bufdesc_ex;
 	int	pause_flag;
 	int	wol_flag;
+	int	wake_irq;
 	u32	quirks;
 
 	struct	napi_struct napi;

drivers/net/ethernet/freescale/fec_main.c

@@ -142,7 +142,7 @@ static const struct fec_devinfo fec_imx8mq_info = {
 		  FEC_QUIRK_ERR007885 | FEC_QUIRK_BUG_CAPTURE |
 		  FEC_QUIRK_HAS_RACC | FEC_QUIRK_HAS_COALESCE |
 		  FEC_QUIRK_CLEAR_SETUP_MII | FEC_QUIRK_HAS_MULTI_QUEUES |
-		  FEC_QUIRK_HAS_EEE,
+		  FEC_QUIRK_HAS_EEE | FEC_QUIRK_WAKEUP_FROM_INT2,
 };
 
 static const struct fec_devinfo fec_imx8qm_info = {
@@ -2878,12 +2878,12 @@ fec_enet_set_wol(struct net_device *ndev, struct ethtool_wolinfo *wol)
 	device_set_wakeup_enable(&ndev->dev, wol->wolopts & WAKE_MAGIC);
 	if (device_may_wakeup(&ndev->dev)) {
 		fep->wol_flag |= FEC_WOL_FLAG_ENABLE;
-		if (fep->irq[0] > 0)
-			enable_irq_wake(fep->irq[0]);
+		if (fep->wake_irq > 0)
+			enable_irq_wake(fep->wake_irq);
 	} else {
 		fep->wol_flag &= (~FEC_WOL_FLAG_ENABLE);
-		if (fep->irq[0] > 0)
-			disable_irq_wake(fep->irq[0]);
+		if (fep->wake_irq > 0)
+			disable_irq_wake(fep->wake_irq);
 	}
 
 	return 0;
@@ -3696,6 +3696,17 @@ static int fec_enet_get_irq_cnt(struct platform_device *pdev)
 	return irq_cnt;
 }
 
+static void fec_enet_get_wakeup_irq(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct fec_enet_private *fep = netdev_priv(ndev);
+
+	if (fep->quirks & FEC_QUIRK_WAKEUP_FROM_INT2)
+		fep->wake_irq = fep->irq[2];
+	else
+		fep->wake_irq = fep->irq[0];
+}
+
 static int fec_enet_init_stop_mode(struct fec_enet_private *fep,
 				   struct device_node *np)
 {
@@ -3935,6 +3946,9 @@ fec_probe(struct platform_device *pdev)
 		fep->irq[i] = irq;
 	}
 
+	/* Decide which interrupt line is wakeup capable */
+	fec_enet_get_wakeup_irq(pdev);
+
 	ret = fec_enet_mii_init(pdev);
 	if (ret)
 		goto failed_mii_init;