ath79: backport phy reset-controller patches

The Siemens WS-AP3610 asserts reset to the ethernet PHY with the
reset-register. Backport the necessary patches to de-assert reset
when probing the PHY.

These patches can be dropped when using kernel 5.4.

Signed-off-by: David Bauer <mail@david-bauer.net>

target/linux/ath79/patches-4.19/701-mdio-bus-dont-use-managed-reset-controller.patch

@@ -0,0 +1,44 @@
+From 32085f25d7b68404055f3525c780142fc72e543f Mon Sep 17 00:00:00 2001
+From: David Bauer <mail@david-bauer.net>
+Date: Fri, 22 Nov 2019 22:44:51 +0100
+Subject: [PATCH] mdio_bus: don't use managed reset-controller
+
+Geert Uytterhoeven reported that using devm_reset_controller_get leads
+to a WARNING when probing a reset-controlled PHY. This is because the
+device devm_reset_controller_get gets supplied is not actually the
+one being probed.
+
+Acquire an unmanaged reset-control as well as free the reset_control on
+unregister to fix this.
+
+Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
+CC: Andrew Lunn <andrew@lunn.ch>
+Signed-off-by: David Bauer <mail@david-bauer.net>
+Reviewed-by: Andrew Lunn <andrew@lunn.ch>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ drivers/net/phy/mdio_bus.c | 6 ++++--
+ 1 file changed, 4 insertions(+), 2 deletions(-)
+
+--- a/drivers/net/phy/mdio_bus.c
++++ b/drivers/net/phy/mdio_bus.c
+@@ -74,8 +74,8 @@ static int mdiobus_register_reset(struct
+ 	struct reset_control *reset = NULL;
+ 
+ 	if (mdiodev->dev.of_node)
+-		reset = devm_reset_control_get_exclusive(&mdiodev->dev,
+-							 "phy");
++		reset = of_reset_control_get_exclusive(mdiodev->dev.of_node,
++						       "phy");
+ 	if (PTR_ERR(reset) == -ENOENT ||
+ 	    PTR_ERR(reset) == -ENOTSUPP)
+ 		reset = NULL;
+@@ -118,6 +118,8 @@ int mdiobus_unregister_device(struct mdi
+ 	if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
+ 		return -EINVAL;
+ 
++	reset_control_put(mdiodev->reset_ctrl);
++
+ 	mdiodev->bus->mdio_map[mdiodev->addr] = NULL;
+ 
+ 	return 0;