[PATCH v2 2/2] net: xilinx_axi: check PCS/PMA PHY status in setup_phy

[Andy Chiu]

Both PCS/PMA PHY and the external PHY need to have a valid link status
in order to have Ethernet traffic. Check and wait this status at
setup_phy() so that we could diagnose if there is a PHY issue.

Signed-off-by: Andy Chiu <andy.c...@sifive.com>
Reviewed-by: Greentime Hu <greentime...@sifive.com>
---
 drivers/net/xilinx_axi_emac.c | 44 +++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/drivers/net/xilinx_axi_emac.c b/drivers/net/xilinx_axi_emac.c
index cb5487c437..10204db79b 100644
--- a/drivers/net/xilinx_axi_emac.c
+++ b/drivers/net/xilinx_axi_emac.c
@@ -336,6 +336,45 @@ static int axiemac_phy_init(struct udevice *dev)
        return 0;
 }
 
+static int pcs_pma_startup(struct axidma_priv *priv)
+{
+       u32 rc, retry_cnt = 0;
+       u16 mii_reg;
+
+       rc = phyread(priv, priv->pcsaddr, MII_BMCR, &mii_reg);
+       if (rc)
+               goto failed_mdio;
+
+       if (!(mii_reg & BMCR_ANENABLE)) {
+               mii_reg |= BMCR_ANENABLE;
+               if (phywrite(priv, priv->pcsaddr, MII_BMCR, mii_reg))
+                       goto failed_mdio;
+       }
+
+       /*
+        * Check the internal PHY status and warn user if the link between it
+        * and the external PHY is not obtained.
+        */
+       debug("axiemac: waiting for link status of the PCS/PMA PHY");
+       while (retry_cnt * 10 < PHY_ANEG_TIMEOUT) {
+               rc = phyread(priv, priv->pcsaddr, MII_BMSR, &mii_reg);
+               if ((mii_reg & BMSR_LSTATUS) && mii_reg != 0xffff && !rc) {
+                       debug(".Done\n");
+                       return 0;
+               }
+               if ((retry_cnt++ % 10) == 0)
+                       debug(".");
+               mdelay(10);
+       }
+       debug("\n");
+       printf("axiemac: Warning, PCS/PMA PHY@%d is not ready, link is down\n",
+              priv->pcsaddr);
+       return 1;
+failed_mdio:
+       printf("axiemac: MDIO to the PCS/PMA PHY has failed\n");
+       return 1;
+}
+
 /* Setting axi emac and phy to proper setting */
 static int setup_phy(struct udevice *dev)
 {
@@ -367,6 +406,11 @@ static int setup_phy(struct udevice *dev)
                       phydev->dev->name);
                return 0;
        }
+       if (priv->interface == PHY_INTERFACE_MODE_SGMII ||
+           priv->interface == PHY_INTERFACE_MODE_1000BASEX) {
+               if (pcs_pma_startup(priv))
+                       return 0;
+       }
        if (!phydev->link) {
                printf("%s: No link.\n", phydev->dev->name);
                return 0;
-- 
2.36.0