[PATCH net] net: ethernet: mediatek: rework GDM setup flow

[MarkLee <Mark-MC.Lee@mediatek.com>]

net: ethernet: mediatek: rework GDM setup flow

The mt762x GDM block is mainly used to setup the HW 
internal rx path - from GMAC port to RX DMA engine(PDMA/QDMA). 
And the internal packet switching engine(PSE) is responsed 
to do the data forward/drop following the GDM configuration.

This pacth target to simpfy the GDM setup flow by integrating 
them into one single function "mtk_gdm_config".
Besides, accroding to the mt762x HW design, it is recommended to 
enable PSE to forward data after DMA has been started and 
set PSE to drop all data before stopping DMA. 

Note, mt7628 is a different IP from other mt762x, so we exclude it
in mtk_gdm_config function.

Signed-off-by: MarkLee <Mark-MC.Lee@mediatek.com>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 44 ++++++++++++++-------
 drivers/net/ethernet/mediatek/mtk_eth_soc.h |  2 +
 2 files changed, 31 insertions(+), 15 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 703adb96429e..7220abb3e731 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -2180,6 +2180,31 @@ static int mtk_start_dma(struct mtk_eth *eth)
 	return 0;
 }
 
+static void mtk_gdm_config(struct mtk_eth *eth, u32 config)
+{
+	int i;
+
+	if (MTK_HAS_CAPS(eth->soc->caps, MTK_SOC_MT7628))
+		return;
+
+	for (i = 0; i < 2; i++) {
+		u32 val = mtk_r32(eth, MTK_GDMA_FWD_CFG(i));
+
+		/* Always enable RX checksum */
+		val |= MTK_GDMA_ICS_EN | MTK_GDMA_TCS_EN | MTK_GDMA_UCS_EN;
+
+		/* default setup the forward port to send frame to PDMA */
+		val &= ~0xffff;
+
+		val |= config;
+
+		mtk_w32(eth, val, MTK_GDMA_FWD_CFG(i));
+	}
+	/*Reset and enable PSE*/
+	mtk_w32(eth, RST_GL_PSE, MTK_RST_GL);
+	mtk_w32(eth, 0, MTK_RST_GL);
+}
+
 static int mtk_open(struct net_device *dev)
 {
 	struct mtk_mac *mac = netdev_priv(dev);
@@ -2200,6 +2225,8 @@ static int mtk_open(struct net_device *dev)
 		if (err)
 			return err;
 
+		mtk_gdm_config(eth, MTK_GDMA_TO_PDMA);
+
 		napi_enable(&eth->tx_napi);
 		napi_enable(&eth->rx_napi);
 		mtk_tx_irq_enable(eth, MTK_TX_DONE_INT);
@@ -2252,6 +2279,8 @@ static int mtk_stop(struct net_device *dev)
 	if (!refcount_dec_and_test(&eth->dma_refcnt))
 		return 0;
 
+	mtk_gdm_config(eth, MTK_GDMA_DROP_ALL);
+
 	mtk_tx_irq_disable(eth, MTK_TX_DONE_INT);
 	mtk_rx_irq_disable(eth, MTK_RX_DONE_INT);
 	napi_disable(&eth->tx_napi);
@@ -2375,8 +2404,6 @@ static int mtk_hw_init(struct mtk_eth *eth)
 	mtk_w32(eth, 0, MTK_QDMA_DELAY_INT);
 	mtk_tx_irq_disable(eth, ~0);
 	mtk_rx_irq_disable(eth, ~0);
-	mtk_w32(eth, RST_GL_PSE, MTK_RST_GL);
-	mtk_w32(eth, 0, MTK_RST_GL);
 
 	/* FE int grouping */
 	mtk_w32(eth, MTK_TX_DONE_INT, MTK_PDMA_INT_GRP1);
@@ -2385,19 +2412,6 @@ static int mtk_hw_init(struct mtk_eth *eth)
 	mtk_w32(eth, MTK_RX_DONE_INT, MTK_QDMA_INT_GRP2);
 	mtk_w32(eth, 0x21021000, MTK_FE_INT_GRP);
 
-	for (i = 0; i < MTK_MAC_COUNT; i++) {
-		u32 val = mtk_r32(eth, MTK_GDMA_FWD_CFG(i));
-
-		/* setup the forward port to send frame to PDMA */
-		val &= ~0xffff;
-
-		/* Enable RX checksum */
-		val |= MTK_GDMA_ICS_EN | MTK_GDMA_TCS_EN | MTK_GDMA_UCS_EN;
-
-		/* setup the mac dma */
-		mtk_w32(eth, val, MTK_GDMA_FWD_CFG(i));
-	}
-
 	return 0;
 
 err_disable_pm:
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 76bd12cb8150..b8bcfdfc995e 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -84,6 +84,8 @@
 #define MTK_GDMA_ICS_EN		BIT(22)
 #define MTK_GDMA_TCS_EN		BIT(21)
 #define MTK_GDMA_UCS_EN		BIT(20)
+#define MTK_GDMA_DROP_ALL	0x7777
+#define MTK_GDMA_TO_PDMA	0x0
 
 /* Unicast Filter MAC Address Register - Low */
 #define MTK_GDMA_MAC_ADRL(x)	(0x508 + (x * 0x1000))
-- 
2.17.1