[PATCH net-next 3/4] net: phy: smsc: fix and improve WoL support

[Gatien Chevallier <gatien.chevallier@foss.st.com>]

Add suspend()/resume() callbacks that do not shut down the PHY if the
WoL is supported and handle the WoL status flags.

If the WoL is supported by the PHY, indicate that the PHY device can
be a source of wake up for the platform. When setting the WoL
configuration, enable this capability.

Fixes: 8b305ee2a91c ("net: phy: smsc: add WoL support to LAN8740/LAN8742 PHYs")
Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
---
 drivers/net/phy/smsc.c  | 42 ++++++++++++++++++++++++++++++++++++++----
 include/linux/smscphy.h |  2 ++
 2 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/drivers/net/phy/smsc.c b/drivers/net/phy/smsc.c
index b6489da5cfcdfb405457058dc88575c0d84d259d..cf4e763907aefd2d725c734d3e0f2926128f770e 100644
--- a/drivers/net/phy/smsc.c
+++ b/drivers/net/phy/smsc.c
@@ -537,14 +537,45 @@ static int lan874x_set_wol(struct phy_device *phydev,
 		}
 	}
 
-	rc = phy_write_mmd(phydev, MDIO_MMD_PCS, MII_LAN874X_PHY_MMD_WOL_WUCSR,
-			   val_wucsr);
+	/* Enable wakeup on PHY device if at least one WoL feature is configured */
+	device_set_wakeup_enable(&phydev->mdio.dev, !!(val_wucsr & MII_LAN874X_PHY_WOL_MASK));
+
+	rc = phy_write_mmd(phydev, MDIO_MMD_PCS, MII_LAN874X_PHY_MMD_WOL_WUCSR, val_wucsr);
 	if (rc < 0)
 		return rc;
 
 	return 0;
 }
 
+static int smsc_phy_suspend(struct phy_device *phydev)
+{
+	if (!phydev->wol_enabled)
+		return genphy_suspend(phydev);
+
+	return 0;
+}
+
+static int smsc_phy_resume(struct phy_device *phydev)
+{
+	int rc;
+
+	if (!phydev->wol_enabled)
+		return genphy_resume(phydev);
+
+	rc = phy_read_mmd(phydev, MDIO_MMD_PCS, MII_LAN874X_PHY_MMD_WOL_WUCSR);
+	if (rc < 0)
+		return rc;
+
+	if (!(rc & MII_LAN874X_PHY_WOL_STATUS_MASK))
+		return 0;
+
+	dev_info(&phydev->mdio.dev, "Woke up from LAN event.\n");
+	rc = phy_write_mmd(phydev, MDIO_MMD_PCS, MII_LAN874X_PHY_MMD_WOL_WUCSR,
+			   rc | MII_LAN874X_PHY_WOL_STATUS_MASK);
+
+	return rc;
+}
+
 static int smsc_get_sset_count(struct phy_device *phydev)
 {
 	return ARRAY_SIZE(smsc_hw_stats);
@@ -673,6 +704,9 @@ int smsc_phy_probe(struct phy_device *phydev)
 
 	phydev->priv = priv;
 
+	if (phydev->drv->set_wol)
+		device_set_wakeup_capable(&phydev->mdio.dev, true);
+
 	/* Make clk optional to keep DTB backward compatibility. */
 	refclk = devm_clk_get_optional_enabled_with_rate(dev, NULL,
 							 50 * 1000 * 1000);
@@ -875,8 +909,8 @@ static struct phy_driver smsc_phy_driver[] = {
 	.set_wol	= lan874x_set_wol,
 	.get_wol	= lan874x_get_wol,
 
-	.suspend	= genphy_suspend,
-	.resume		= genphy_resume,
+	.suspend	= smsc_phy_suspend,
+	.resume		= smsc_phy_resume,
 } };
 
 module_phy_driver(smsc_phy_driver);
diff --git a/include/linux/smscphy.h b/include/linux/smscphy.h
index 1a6a851d2cf80d225bada7adeb79969e625964bd..cdf266960032609241afc8316da23f1c4834bfee 100644
--- a/include/linux/smscphy.h
+++ b/include/linux/smscphy.h
@@ -65,6 +65,8 @@ int smsc_phy_probe(struct phy_device *phydev);
 #define MII_LAN874X_PHY_WOL_WUEN		BIT(2)
 #define MII_LAN874X_PHY_WOL_MPEN		BIT(1)
 #define MII_LAN874X_PHY_WOL_BCSTEN		BIT(0)
+#define MII_LAN874X_PHY_WOL_MASK		GENMASK(4, 0)
+#define MII_LAN874X_PHY_WOL_STATUS_MASK		GENMASK(7, 4)
 
 #define MII_LAN874X_PHY_WOL_FILTER_EN		BIT(15)
 #define MII_LAN874X_PHY_WOL_FILTER_MCASTTEN	BIT(9)

-- 
2.35.3