Merge branch 'rework-irq-handling-in-mtk_eth_soc'

Frank Wunderlich says:

====================
rework IRQ handling in mtk_eth_soc

From: Frank Wunderlich <frank-w@public-files.de>

This series introduces named IRQs while keeping the index based way
for older dts.
Further it makes some cleanup like adding consts for index access and
avoids loading first IRQ which was not used on non SHARED_INT SoCs.
====================

Link: https://patch.msgid.link/20250619132125.78368-1-linux@fw-web.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 58 insertions, 18 deletions

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index b38e4f2de674..f8a907747db4 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -3336,6 +3336,48 @@ static void mtk_tx_timeout(struct net_device *dev, unsigned int txqueue)
 	schedule_work(&eth->pending_work);
 }
 
+static int mtk_get_irqs(struct platform_device *pdev, struct mtk_eth *eth)
+{
+	int i;
+
+	/* future SoCs beginning with MT7988 should use named IRQs in dts */
+	eth->irq[MTK_FE_IRQ_TX] = platform_get_irq_byname(pdev, "fe1");
+	eth->irq[MTK_FE_IRQ_RX] = platform_get_irq_byname(pdev, "fe2");
+	if (eth->irq[MTK_FE_IRQ_TX] >= 0 && eth->irq[MTK_FE_IRQ_RX] >= 0)
+		return 0;
+
+	/* only use legacy mode if platform_get_irq_byname returned -ENXIO */
+	if (eth->irq[MTK_FE_IRQ_TX] != -ENXIO)
+		return eth->irq[MTK_FE_IRQ_TX];
+
+	if (eth->irq[MTK_FE_IRQ_RX] != -ENXIO)
+		return eth->irq[MTK_FE_IRQ_RX];
+
+	/* legacy way:
+	 * On MTK_SHARED_INT SoCs (MT7621 + MT7628) the first IRQ is taken
+	 * from devicetree and used for both RX and TX - it is shared.
+	 * On SoCs with non-shared IRQs the first entry is not used,
+	 * the second is for TX, and the third is for RX.
+	 */
+	for (i = 0; i < MTK_FE_IRQ_NUM; i++) {
+		if (MTK_HAS_CAPS(eth->soc->caps, MTK_SHARED_INT)) {
+			if (i == MTK_FE_IRQ_SHARED)
+				eth->irq[MTK_FE_IRQ_SHARED] = platform_get_irq(pdev, i);
+			else
+				eth->irq[i] = eth->irq[MTK_FE_IRQ_SHARED];
+		} else {
+			eth->irq[i] = platform_get_irq(pdev, i + 1);
+		}
+
+		if (eth->irq[i] < 0) {
+			dev_err(&pdev->dev, "no IRQ%d resource found\n", i);
+			return -ENXIO;
+		}
+	}
+
+	return 0;
+}
+
 static irqreturn_t mtk_handle_irq_rx(int irq, void *_eth)
 {
 	struct mtk_eth *eth = _eth;
@@ -3389,7 +3431,7 @@ static void mtk_poll_controller(struct net_device *dev)
 
 	mtk_tx_irq_disable(eth, MTK_TX_DONE_INT);
 	mtk_rx_irq_disable(eth, eth->soc->rx.irq_done_mask);
-	mtk_handle_irq_rx(eth->irq[2], dev);
+	mtk_handle_irq_rx(eth->irq[MTK_FE_IRQ_RX], dev);
 	mtk_tx_irq_enable(eth, MTK_TX_DONE_INT);
 	mtk_rx_irq_enable(eth, eth->soc->rx.irq_done_mask);
 }
@@ -4875,7 +4917,7 @@ static int mtk_add_mac(struct mtk_eth *eth, struct device_node *np)
 	eth->netdev[id]->features |= eth->soc->hw_features;
 	eth->netdev[id]->ethtool_ops = &mtk_ethtool_ops;
 
-	eth->netdev[id]->irq = eth->irq[0];
+	eth->netdev[id]->irq = eth->irq[MTK_FE_IRQ_SHARED];
 	eth->netdev[id]->dev.of_node = np;
 
 	if (MTK_HAS_CAPS(eth->soc->caps, MTK_SOC_MT7628))
@@ -5105,17 +5147,10 @@ static int mtk_probe(struct platform_device *pdev)
 		}
 	}
 
-	for (i = 0; i < 3; i++) {
-		if (MTK_HAS_CAPS(eth->soc->caps, MTK_SHARED_INT) && i > 0)
-			eth->irq[i] = eth->irq[0];
-		else
-			eth->irq[i] = platform_get_irq(pdev, i);
-		if (eth->irq[i] < 0) {
-			dev_err(&pdev->dev, "no IRQ%d resource found\n", i);
-			err = -ENXIO;
-			goto err_wed_exit;
-		}
-	}
+	err = mtk_get_irqs(pdev, eth);
+	if (err)
+		goto err_wed_exit;
+
 	for (i = 0; i < ARRAY_SIZE(eth->clks); i++) {
 		eth->clks[i] = devm_clk_get(eth->dev,
 					    mtk_clks_source_name[i]);
@@ -5159,17 +5194,17 @@ static int mtk_probe(struct platform_device *pdev)
 	}
 
 	if (MTK_HAS_CAPS(eth->soc->caps, MTK_SHARED_INT)) {
-		err = devm_request_irq(eth->dev, eth->irq[0],
+		err = devm_request_irq(eth->dev, eth->irq[MTK_FE_IRQ_SHARED],
 				       mtk_handle_irq, 0,
 				       dev_name(eth->dev), eth);
 	} else {
-		err = devm_request_irq(eth->dev, eth->irq[1],
+		err = devm_request_irq(eth->dev, eth->irq[MTK_FE_IRQ_TX],
 				       mtk_handle_irq_tx, 0,
 				       dev_name(eth->dev), eth);
 		if (err)
 			goto err_free_dev;
 
-		err = devm_request_irq(eth->dev, eth->irq[2],
+		err = devm_request_irq(eth->dev, eth->irq[MTK_FE_IRQ_RX],
 				       mtk_handle_irq_rx, 0,
 				       dev_name(eth->dev), eth);
 	}
@@ -5215,7 +5250,7 @@ static int mtk_probe(struct platform_device *pdev)
 		} else
 			netif_info(eth, probe, eth->netdev[i],
 				   "mediatek frame engine at 0x%08lx, irq %d\n",
-				   eth->netdev[i]->base_addr, eth->irq[0]);
+				   eth->netdev[i]->base_addr, eth->irq[MTK_FE_IRQ_SHARED]);
 	}
 
 	/* we run 2 devices on the same DMA ring so we need a dummy device
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 6f72a8c8ae1e..9261c0e13b59 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -642,6 +642,11 @@
 
 #define MTK_MAC_FSM(x)		(0x1010C + ((x) * 0x100))
 
+#define MTK_FE_IRQ_SHARED	0
+#define MTK_FE_IRQ_TX		0
+#define MTK_FE_IRQ_RX		1
+#define MTK_FE_IRQ_NUM		(MTK_FE_IRQ_RX + 1)
+
 struct mtk_rx_dma {
 	unsigned int rxd1;
 	unsigned int rxd2;
@@ -1292,7 +1297,7 @@ struct mtk_eth {
 	struct net_device		*dummy_dev;
 	struct net_device		*netdev[MTK_MAX_DEVS];
 	struct mtk_mac			*mac[MTK_MAX_DEVS];
-	int				irq[3];
+	int				irq[MTK_FE_IRQ_NUM];
 	u32				msg_enable;
 	unsigned long			sysclk;
 	struct regmap			*ethsys;