net: usb/phy: asix: add support for ax88772A/C PHYs

Add support for build-in x88772A/C PHYs

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/ax88796b.c

@@ -10,6 +10,8 @@
 #include <linux/mii.h>
 #include <linux/phy.h>
 
+#define PHY_ID_ASIX_AX88772A 0x003b1861
+#define PHY_ID_ASIX_AX88772C 0x003b1881
 #define PHY_ID_ASIX_AX88796B 0x003b1841
 
 MODULE_DESCRIPTION("Asix PHY driver");
@@ -39,7 +41,75 @@ static int asix_soft_reset(struct phy_device *phydev)
  return genphy_soft_reset(phydev);
 }
 
-static struct phy_driver asix_driver[] = { {
+/* AX88772A is not working properly with some old switches (NETGEAR EN 108TP):
+ * after autoneg is done and the link status is reported as active, the MII_LPA
+ * register is 0. This issue is not reproducible on AX88772C.
+ */
+static int asix_ax88772a_read_status(struct phy_device *phydev)
+{
+ int ret, val;
+
+ ret = genphy_update_link(phydev);
+ if (ret)
+ return ret;
+
+ if (!phydev->link)
+ return 0;
+
+ /* If MII_LPA is 0, phy_resolve_aneg_linkmode() will fail to resolve
+ * linkmode so use MII_BMCR as default values.
+ */
+ val = phy_read(phydev, MII_BMCR);
+ if (val < 0)
+ return val;
+
+ if (val & BMCR_SPEED100)
+ phydev->speed = SPEED_100;
+ else
+ phydev->speed = SPEED_10;
+
+ if (val & BMCR_FULLDPLX)
+ phydev->duplex = DUPLEX_FULL;
+ else
+ phydev->duplex = DUPLEX_HALF;
+
+ ret = genphy_read_lpa(phydev);
+ if (ret < 0)
+ return ret;
+
+ if (phydev->autoneg == AUTONEG_ENABLE && phydev->autoneg_complete)
+ phy_resolve_aneg_linkmode(phydev);
+
+ return 0;
+}
+
+static void asix_ax88772a_link_change_notify(struct phy_device *phydev)
+{
+ /* Reset PHY, otherwise MII_LPA will provide outdated information.
+ * This issue is reproducible only with some link partner PHYs
+ */
+ if (phydev->state == PHY_NOLINK && phydev->drv->soft_reset)
+ phydev->drv->soft_reset(phydev);
+}
+
+static struct phy_driver asix_driver[] = {
+{
+ PHY_ID_MATCH_EXACT(PHY_ID_ASIX_AX88772A),
+ .name = "Asix Electronics AX88772A",
+ .flags = PHY_IS_INTERNAL,
+ .read_status = asix_ax88772a_read_status,
+ .suspend = genphy_suspend,
+ .resume = genphy_resume,
+ .soft_reset = asix_soft_reset,
+ .link_change_notify = asix_ax88772a_link_change_notify,
+}, {
+ PHY_ID_MATCH_EXACT(PHY_ID_ASIX_AX88772C),
+ .name = "Asix Electronics AX88772C",
+ .flags = PHY_IS_INTERNAL,
+ .suspend = genphy_suspend,
+ .resume = genphy_resume,
+ .soft_reset = asix_soft_reset,
+}, {
  .phy_id = PHY_ID_ASIX_AX88796B,
  .name = "Asix Electronics AX88796B",
  .phy_id_mask = 0xfffffff0,
@@ -50,6 +120,8 @@ static struct phy_driver asix_driver[] = { {
 module_phy_driver(asix_driver);
 
 static struct mdio_device_id __maybe_unused asix_tbl[] = {
+ { PHY_ID_MATCH_EXACT(PHY_ID_ASIX_AX88772A) },
+ { PHY_ID_MATCH_EXACT(PHY_ID_ASIX_AX88772C) },
  { PHY_ID_ASIX_AX88796B, 0xfffffff0 },
  { }
 };

drivers/net/usb/Kconfig

@@ -164,6 +164,7 @@ config USB_NET_AX8817X
  depends on USB_USBNET
  select CRC32
  select PHYLIB
+ select AX88796B_PHY
  default y
  help
  This option adds support for ASIX AX88xxx based USB 2.0