Merge branch 'phy_turn_around'

Florian Fainelli says:

====================
net: phy: broken turn-around support

This is an attempt at solving the broken turn-around problem in a way that
is not specific to the mdio-gpio driver, since it affects different kinds of
platforms.

We cannot make that localized to PHY device drivers because probing the PHY
device which has a broken turn-around can fail as early as in get_phy_id(),
therefore we need a bit of help from Device Tree/platform_data.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/phy.txt

@@ -30,6 +30,9 @@ Optional Properties:
 
 - max-speed: Maximum PHY supported speed (10, 100, 1000...)
 
+- broken-turn-around: If set, indicates the PHY device does not correctly
+  release the turn around line low at the end of a MDIO transaction.
+
 Example:
 
 ethernet-phy@0 {

drivers/net/phy/mdio-bitbang.c

@@ -165,8 +165,11 @@ static int mdiobb_read(struct mii_bus *bus, int phy, int reg)
 
 	ctrl->ops->set_mdio_dir(ctrl, 0);
 
-	/* check the turnaround bit: the PHY should be driving it to zero */
-	if (mdiobb_get_bit(ctrl) != 0) {
+	/* check the turnaround bit: the PHY should be driving it to zero, if this
+	 * PHY is listed in phy_ignore_ta_mask as having broken TA, skip that
+	 */
+	if (mdiobb_get_bit(ctrl) != 0 &&
+	    !(bus->phy_ignore_ta_mask & (1 << phy))) {
 		/* PHY didn't drive TA low -- flush any bits it
 		 * may be trying to send.
 		 */

drivers/of/of_mdio.c

@@ -68,6 +68,9 @@ static int of_mdiobus_register_phy(struct mii_bus *mdio, struct device_node *chi
 			phy->irq = mdio->irq[addr];
 	}
 
+	if (of_property_read_bool(child, "broken-turn-around"))
+		mdio->phy_ignore_ta_mask |= 1 << addr;
+
 	/* Associate the OF node with the device structure so it
 	 * can be looked up later */
 	of_node_get(child);

include/linux/phy.h

@@ -181,6 +181,9 @@ struct mii_bus {
 	/* PHY addresses to be ignored when probing */
 	u32 phy_mask;
 
+	/* PHY addresses to ignore the TA/read failure */
+	u32 phy_ignore_ta_mask;
+
 	/*
 	 * Pointer to an array of interrupts, each PHY's
 	 * interrupt at the index matching its address