[U-Boot] [PATCH v3 17/28] net: mt7628-eth: make phy link up detection optional via DT

[Weijie Gao]

The mt7628 has an embedded ethernet switch (5 phy ports + 1 cpu port).
Although in IOT mode only port0 is usable, the phy0 is still connected
to the switch, not the ethernet gmac directly.

This patch rewrites it and makes it optional. It can be turned on by adding
mediatek,poll-link-phy = <?> explicitly into the eth node. By default the
driver is switch mode with all 5 phy ports working without link detection.

Signed-off-by: Weijie Gao <weijie.gao at mediatek.com>
---
v2: Make link detection optional rather than removing directly.
---
 drivers/net/Kconfig      |  1 +
 drivers/net/mt7628-eth.c | 59 ++++++++++++++++++++--------------------
 2 files changed, 31 insertions(+), 29 deletions(-)

diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 2ce3092db0..eb3d7ed45f 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -322,6 +322,7 @@ config MACB_ZYNQ
 config MT7628_ETH
 	bool "MediaTek MT7628 Ethernet Interface"
 	depends on SOC_MT7628
+	select PHYLIB
 	help
 	  The MediaTek MT7628 ethernet interface is used on MT7628 and
 	  MT7688 based boards.
diff --git a/drivers/net/mt7628-eth.c b/drivers/net/mt7628-eth.c
index 4675b0f003..abfdc75ad8 100644
--- a/drivers/net/mt7628-eth.c
+++ b/drivers/net/mt7628-eth.c
@@ -111,6 +111,7 @@ struct fe_tx_dma {
 
 #define NUM_RX_DESC		256
 #define NUM_TX_DESC		4
+#define NUM_PHYS		5
 
 #define PADDING_LENGTH		60
 
@@ -120,9 +121,6 @@ struct fe_tx_dma {
 #define CONFIG_DMA_STOP_TIMEOUT	100
 #define CONFIG_TX_DMA_TIMEOUT	100
 
-#define LINK_DELAY_TIME		500		/* 500 ms */
-#define LINK_TIMEOUT		10000		/* 10 seconds */
-
 struct mt7628_eth_dev {
 	void __iomem *base;		/* frame engine base address */
 	void __iomem *eth_sw_base;	/* switch base address */
@@ -140,6 +138,8 @@ struct mt7628_eth_dev {
 	int tx_dma_idx;
 
 	struct reset_ctl	rst_ephy;
+
+	struct phy_device *phy;
 };
 
 static int mdio_wait_read(struct mt7628_eth_dev *priv, u32 mask, bool mask_set)
@@ -437,20 +437,13 @@ static int mt7628_eth_free_pkt(struct udevice *dev, uchar *packet, int length)
 	return 0;
 }
 
-static int phy_link_up(struct mt7628_eth_dev *priv)
-{
-	u32 val;
-
-	mii_mgr_read(priv, 0x00, MII_BMSR, &val);
-	return !!(val & BMSR_LSTATUS);
-}
-
 static int mt7628_eth_start(struct udevice *dev)
 {
 	struct mt7628_eth_dev *priv = dev_get_priv(dev);
 	void __iomem *base = priv->base;
 	uchar packet[MTK_QDMA_PAGE_SIZE];
 	uchar *packetp;
+	int ret;
 	int i;
 
 	for (i = 0; i < NUM_RX_DESC; i++) {
@@ -493,25 +486,13 @@ static int mt7628_eth_start(struct udevice *dev)
 	wmb();
 	eth_dma_start(priv);
 
-	/* Check if link is not up yet */
-	if (!phy_link_up(priv)) {
-		/* Wait for link to come up */
-
-		printf("Waiting for link to come up .");
-		for (i = 0; i < (LINK_TIMEOUT / LINK_DELAY_TIME); i++) {
-			mdelay(LINK_DELAY_TIME);
-			if (phy_link_up(priv)) {
-				mdelay(100);	/* Ensure all is ready */
-				break;
-			}
+	if (priv->phy) {
+		ret = phy_startup(priv->phy);
+		if (ret)
+			return ret;
 
-			printf(".");
-		}
-
-		if (phy_link_up(priv))
-			printf(" done\n");
-		else
-			printf(" timeout! Trying anyways\n");
+		if (!priv->phy->link)
+			return -EAGAIN;
 	}
 
 	/*
@@ -538,6 +519,7 @@ static int mt7628_eth_probe(struct udevice *dev)
 {
 	struct mt7628_eth_dev *priv = dev_get_priv(dev);
 	struct mii_dev *bus;
+	int poll_link_phy;
 	int ret;
 	int i;
 
@@ -584,6 +566,25 @@ static int mt7628_eth_probe(struct udevice *dev)
 	if (ret)
 		return ret;
 
+	poll_link_phy = dev_read_u32_default(dev, "mediatek,poll-link-phy", -1);
+	if (poll_link_phy >= 0) {
+		if (poll_link_phy >= NUM_PHYS) {
+			pr_err("invalid phy %d for poll-link-phy\n",
+			       poll_link_phy);
+			return ret;
+		}
+
+		priv->phy = phy_connect(bus, poll_link_phy, dev,
+					PHY_INTERFACE_MODE_MII);
+		if (!priv->phy) {
+			pr_err("failed to probe phy %d\n", poll_link_phy);
+			return -ENODEV;
+		}
+
+		priv->phy->advertising = priv->phy->supported;
+		phy_config(priv->phy);
+	}
+
 	/* Switch configuration */
 	rt305x_esw_init(priv);
 
-- 
2.17.1