net: macb: Add WoL interrupt support for MACB type of Ethernet controller

Handle the Wake-on-Lan interrupt for the Cadence MACB Ethernet
controller.
As we do for the GEM version, we handle of WoL interrupt in a
specialized interrupt handler for MACB version that is positionned
just between suspend() and resume() calls.

Cc: Claudiu Beznea <claudiu.beznea@microchip.com>
Cc: Harini Katakam <harini.katakam@xilinx.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cadence/macb_main.c

@@ -1517,6 +1517,35 @@ static void macb_tx_restart(struct macb_queue *queue)
 	macb_writel(bp, NCR, macb_readl(bp, NCR) | MACB_BIT(TSTART));
 }
 
+static irqreturn_t macb_wol_interrupt(int irq, void *dev_id)
+{
+	struct macb_queue *queue = dev_id;
+	struct macb *bp = queue->bp;
+	u32 status;
+
+	status = queue_readl(queue, ISR);
+
+	if (unlikely(!status))
+		return IRQ_NONE;
+
+	spin_lock(&bp->lock);
+
+	if (status & MACB_BIT(WOL)) {
+		queue_writel(queue, IDR, MACB_BIT(WOL));
+		macb_writel(bp, WOL, 0);
+		netdev_vdbg(bp->dev, "MACB WoL: queue = %u, isr = 0x%08lx\n",
+			    (unsigned int)(queue - bp->queues),
+			    (unsigned long)status);
+		if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
+			queue_writel(queue, ISR, MACB_BIT(WOL));
+		pm_wakeup_event(&bp->pdev->dev, 0);
+	}
+
+	spin_unlock(&bp->lock);
+
+	return IRQ_HANDLED;
+}
+
 static irqreturn_t gem_wol_interrupt(int irq, void *dev_id)
 {
 	struct macb_queue *queue = dev_id;
@@ -4619,8 +4648,8 @@ static int __maybe_unused macb_suspend(struct device *dev)
 		/* Change interrupt handler and
 		 * Enable WoL IRQ on queue 0
 		 */
+		devm_free_irq(dev, bp->queues[0].irq, bp->queues);
 		if (macb_is_gem(bp)) {
-			devm_free_irq(dev, bp->queues[0].irq, bp->queues);
 			err = devm_request_irq(dev, bp->queues[0].irq, gem_wol_interrupt,
 					       IRQF_SHARED, netdev->name, bp->queues);
 			if (err) {
@@ -4633,6 +4662,15 @@ static int __maybe_unused macb_suspend(struct device *dev)
 			queue_writel(bp->queues, IER, GEM_BIT(WOL));
 			gem_writel(bp, WOL, MACB_BIT(MAG));
 		} else {
+			err = devm_request_irq(dev, bp->queues[0].irq, macb_wol_interrupt,
+					       IRQF_SHARED, netdev->name, bp->queues);
+			if (err) {
+				dev_err(dev,
+					"Unable to request IRQ %d (error %d)\n",
+					bp->queues[0].irq, err);
+				spin_unlock_irqrestore(&bp->lock, flags);
+				return err;
+			}
 			queue_writel(bp->queues, IER, MACB_BIT(WOL));
 			macb_writel(bp, WOL, MACB_BIT(MAG));
 		}