net: phy: Allow BCM54616S PHY to setup internal TX/RX clock delay

This patch allows users to enable/disable internal TX and/or RX clock
delay for BCM54616S PHYs so as to satisfy RGMII timing specifications.

On a particular platform, whether TX and/or RX clock delay is required
depends on how PHY connected to the MAC IP. This requirement can be
specified through "phy-mode" property in the platform device tree.

The patch is inspired by commit 73333626 ("net: phy: Allow BCM5481x
PHYs to setup internal TX/RX clock delay").
Signed-off-by: Tao Ren <taoren@fb.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/broadcom.c

@@ -92,7 +92,7 @@ static int bcm54612e_config_init(struct phy_device *phydev)
 	return 0;
 }
 
-static int bcm5481x_config(struct phy_device *phydev)
+static int bcm54xx_config_clock_delay(struct phy_device *phydev)
 {
 	int rc, val;
 
@@ -429,7 +429,7 @@ static int bcm5481_config_aneg(struct phy_device *phydev)
 	ret = genphy_config_aneg(phydev);
 
 	/* Then we can set up the delay. */
-	bcm5481x_config(phydev);
+	bcm54xx_config_clock_delay(phydev);
 
 	if (of_property_read_bool(np, "enet-phy-lane-swap")) {
 		/* Lane Swap - Undocumented register...magic! */
@@ -442,6 +442,19 @@ static int bcm5481_config_aneg(struct phy_device *phydev)
 	return ret;
 }
 
+static int bcm54616s_config_aneg(struct phy_device *phydev)
+{
+	int ret;
+
+	/* Aneg firsly. */
+	ret = genphy_config_aneg(phydev);
+
+	/* Then we can set up the delay. */
+	bcm54xx_config_clock_delay(phydev);
+
+	return ret;
+}
+
 static int brcm_phy_setbits(struct phy_device *phydev, int reg, int set)
 {
 	int val;
@@ -636,6 +649,7 @@ static struct phy_driver broadcom_drivers[] = {
 	.features	= PHY_GBIT_FEATURES,
 	.flags		= PHY_HAS_INTERRUPT,
 	.config_init	= bcm54xx_config_init,
+	.config_aneg	= bcm54616s_config_aneg,
 	.ack_interrupt	= bcm_phy_ack_intr,
 	.config_intr	= bcm_phy_config_intr,
 }, {