From: Andrew Lunn <andrew@lunn.ch>
Date: Tue, 2 Jan 2018 17:40:26 +0100
Subject: net: mdio: Only perform gpio reset for PHYs
Patch-mainline: v4.16-rc1
Git-commit: ee7e16b66a766e8f922aafe5edf9353b9f37a424
References: bsc#1119113 FATE#326472

Ethernet switch on the MDIO bus have historically performed their own
handling of the GPIO reset line. The resent patch to have the MDIO
core handle the reset has broken the switch drivers, in that they
cannot claim the GPIO. Some switch drivers need more control over the
GPIO line than what the MDIO core provides. So restore the historical
behaviour by only performing a reset of PHYs, not switches.

Fixes: bafbdd527d56 ("phylib: Add device reset GPIO support")
Reported-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/phy/mdio_bus.c |   21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -47,13 +47,10 @@
 
 #include "mdio-boardinfo.h"
 
-int mdiobus_register_device(struct mdio_device *mdiodev)
+static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
 {
 	struct gpio_desc *gpiod = NULL;
 
-	if (mdiodev->bus->mdio_map[mdiodev->addr])
-		return -EBUSY;
-
 	/* Deassert the optional reset signal */
 	if (mdiodev->dev.of_node)
 		gpiod = fwnode_get_named_gpiod(&mdiodev->dev.of_node->fwnode,
@@ -69,6 +66,22 @@ int mdiobus_register_device(struct mdio_
 	/* Assert the reset signal again */
 	mdio_device_reset(mdiodev, 1);
 
+	return 0;
+}
+
+int mdiobus_register_device(struct mdio_device *mdiodev)
+{
+	int err;
+
+	if (mdiodev->bus->mdio_map[mdiodev->addr])
+		return -EBUSY;
+
+	if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
+		err = mdiobus_register_gpiod(mdiodev);
+		if (err)
+			return err;
+	}
+
 	mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;
 
 	return 0;