phy/at8031: enable at8031 to work on interrupt mode

The at8031 can work on polling mode and interrupt mode.
Add ack_interrupt and config intr funcs to enable
interrupt mode for it.

Signed-off-by: Zhao Qiang <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/phy/at803x.c

···
 #define AT803X_MMD_ACCESS_CONTROL		0x0D
 #define AT803X_MMD_ACCESS_CONTROL_DATA		0x0E
 #define AT803X_FUNC_DATA			0x4003
+#define AT803X_INER				0x0012
+#define AT803X_INER_INIT			0xec00
+#define AT803X_INSR				0x0013
 #define AT803X_DEBUG_ADDR			0x1D
 #define AT803X_DEBUG_DATA			0x1E
 #define AT803X_DEBUG_SYSTEM_MODE_CTRL		0x05
···
 	return 0;
 }
 
+static int at803x_ack_interrupt(struct phy_device *phydev)
+{
+	int err;
+
+	err = phy_read(phydev, AT803X_INSR);
+
+	return (err < 0) ? err : 0;
+}
+
+static int at803x_config_intr(struct phy_device *phydev)
+{
+	int err;
+	int value;
+
+	value = phy_read(phydev, AT803X_INER);
+
+	if (phydev->interrupts == PHY_INTERRUPT_ENABLED)
+		err = phy_write(phydev, AT803X_INER,
+				value | AT803X_INER_INIT);
+	else
+		err = phy_write(phydev, AT803X_INER, 0);
+
+	return err;
+}
+
 static struct phy_driver at803x_driver[] = {
 {
 	/* ATHEROS 8035 */
···
 	.flags		= PHY_HAS_INTERRUPT,
 	.config_aneg	= genphy_config_aneg,
 	.read_status	= genphy_read_status,
+	.ack_interrupt  = &at803x_ack_interrupt,
+	.config_intr    = &at803x_config_intr,
 	.driver		= {
 		.owner = THIS_MODULE,
 	},