net: phy: nxp-tja11xx: log critical health state

TJA1102 provides interrupt notification for the critical health states
like overtemperature and undervoltage.

The overtemperature bit is set if package temperature is beyond 155C°.
This functionality was tested by heating the package up to 200C°

The undervoltage bit is set if supply voltage drops beyond some critical
threshold. Currently not tested.

In a typical use case, both of this events should be logged and stored
(or send to some remote system) for further investigations.
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/nxp-tja11xx.c

@@ -47,12 +47,14 @@
 #define MII_INTSRC_LINK_FAIL		BIT(10)
 #define MII_INTSRC_LINK_UP		BIT(9)
 #define MII_INTSRC_MASK			(MII_INTSRC_LINK_FAIL | MII_INTSRC_LINK_UP)
-#define MII_INTSRC_TEMP_ERR		BIT(1)
 #define MII_INTSRC_UV_ERR		BIT(3)
+#define MII_INTSRC_TEMP_ERR		BIT(1)
 
 #define MII_INTEN			22
 #define MII_INTEN_LINK_FAIL		BIT(10)
 #define MII_INTEN_LINK_UP		BIT(9)
+#define MII_INTEN_UV_ERR		BIT(3)
+#define MII_INTEN_TEMP_ERR		BIT(1)
 
 #define MII_COMMSTAT			23
 #define MII_COMMSTAT_LINK_UP		BIT(15)
@@ -607,7 +609,8 @@ static int tja11xx_config_intr(struct phy_device *phydev)
 		if (err)
 			return err;
 
-		value = MII_INTEN_LINK_FAIL | MII_INTEN_LINK_UP;
+		value = MII_INTEN_LINK_FAIL | MII_INTEN_LINK_UP |
+			MII_INTEN_UV_ERR | MII_INTEN_TEMP_ERR;
 		err = phy_write(phydev, MII_INTEN, value);
 	} else {
 		err = phy_write(phydev, MII_INTEN, value);
@@ -622,6 +625,7 @@ static int tja11xx_config_intr(struct phy_device *phydev)
 
 static irqreturn_t tja11xx_handle_interrupt(struct phy_device *phydev)
 {
+	struct device *dev = &phydev->mdio.dev;
 	int irq_status;
 
 	irq_status = phy_read(phydev, MII_INTSRC);
@@ -630,6 +634,11 @@ static irqreturn_t tja11xx_handle_interrupt(struct phy_device *phydev)
 		return IRQ_NONE;
 	}
 
+	if (irq_status & MII_INTSRC_TEMP_ERR)
+		dev_warn(dev, "Overtemperature error detected (temp > 155C°).\n");
+	if (irq_status & MII_INTSRC_UV_ERR)
+		dev_warn(dev, "Undervoltage error detected.\n");
+
 	if (!(irq_status & MII_INTSRC_MASK))
 		return IRQ_NONE;