1 files changed, 87 insertions, 12 deletions

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 54d00a1d2bef..88272b3ac2e2 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -38,6 +38,7 @@
 #include <linux/phy.h>
 #include <linux/io.h>
 #include <linux/uaccess.h>
+#include <linux/gpio/consumer.h>
 
 #include <asm/irq.h>
 
@@ -46,11 +47,41 @@
 
 #include "mdio-boardinfo.h"
 
+static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
+{
+	struct gpio_desc *gpiod = NULL;
+
+	/* Deassert the optional reset signal */
+	if (mdiodev->dev.of_node)
+		gpiod = fwnode_get_named_gpiod(&mdiodev->dev.of_node->fwnode,
+					       "reset-gpios", 0, GPIOD_OUT_LOW,
+					       "PHY reset");
+	if (PTR_ERR(gpiod) == -ENOENT)
+		gpiod = NULL;
+	else if (IS_ERR(gpiod))
+		return PTR_ERR(gpiod);
+
+	mdiodev->reset = gpiod;
+
+	/* 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;
@@ -421,6 +452,9 @@ void mdiobus_unregister(struct mii_bus *bus)
 		if (!mdiodev)
 			continue;
 
+		if (mdiodev->reset)
+			gpiod_put(mdiodev->reset);
+
 		mdiodev->device_remove(mdiodev);
 		mdiodev->device_free(mdiodev);
 	}
@@ -494,6 +528,55 @@ struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
 EXPORT_SYMBOL(mdiobus_scan);
 
 /**
+ * __mdiobus_read - Unlocked version of the mdiobus_read function
+ * @bus: the mii_bus struct
+ * @addr: the phy address
+ * @regnum: register number to read
+ *
+ * Read a MDIO bus register. Caller must hold the mdio bus lock.
+ *
+ * NOTE: MUST NOT be called from interrupt context.
+ */
+int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
+{
+	int retval;
+
+	WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
+
+	retval = bus->read(bus, addr, regnum);
+
+	trace_mdio_access(bus, 1, addr, regnum, retval, retval);
+
+	return retval;
+}
+EXPORT_SYMBOL(__mdiobus_read);
+
+/**
+ * __mdiobus_write - Unlocked version of the mdiobus_write function
+ * @bus: the mii_bus struct
+ * @addr: the phy address
+ * @regnum: register number to write
+ * @val: value to write to @regnum
+ *
+ * Write a MDIO bus register. Caller must hold the mdio bus lock.
+ *
+ * NOTE: MUST NOT be called from interrupt context.
+ */
+int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
+{
+	int err;
+
+	WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
+
+	err = bus->write(bus, addr, regnum, val);
+
+	trace_mdio_access(bus, 0, addr, regnum, val, err);
+
+	return err;
+}
+EXPORT_SYMBOL(__mdiobus_write);
+
+/**
  * mdiobus_read_nested - Nested version of the mdiobus_read function
  * @bus: the mii_bus struct
  * @addr: the phy address
@@ -513,11 +596,9 @@ int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
 	BUG_ON(in_interrupt());
 
 	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
-	retval = bus->read(bus, addr, regnum);
+	retval = __mdiobus_read(bus, addr, regnum);
 	mutex_unlock(&bus->mdio_lock);
 
-	trace_mdio_access(bus, 1, addr, regnum, retval, retval);
-
 	return retval;
 }
 EXPORT_SYMBOL(mdiobus_read_nested);
@@ -539,11 +620,9 @@ int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
 	BUG_ON(in_interrupt());
 
 	mutex_lock(&bus->mdio_lock);
-	retval = bus->read(bus, addr, regnum);
+	retval = __mdiobus_read(bus, addr, regnum);
 	mutex_unlock(&bus->mdio_lock);
 
-	trace_mdio_access(bus, 1, addr, regnum, retval, retval);
-
 	return retval;
 }
 EXPORT_SYMBOL(mdiobus_read);
@@ -569,11 +648,9 @@ int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
 	BUG_ON(in_interrupt());
 
 	mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
-	err = bus->write(bus, addr, regnum, val);
+	err = __mdiobus_write(bus, addr, regnum, val);
 	mutex_unlock(&bus->mdio_lock);
 
-	trace_mdio_access(bus, 0, addr, regnum, val, err);
-
 	return err;
 }
 EXPORT_SYMBOL(mdiobus_write_nested);
@@ -596,11 +673,9 @@ int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
 	BUG_ON(in_interrupt());
 
 	mutex_lock(&bus->mdio_lock);
-	err = bus->write(bus, addr, regnum, val);
+	err = __mdiobus_write(bus, addr, regnum, val);
 	mutex_unlock(&bus->mdio_lock);
 
-	trace_mdio_access(bus, 0, addr, regnum, val, err);
-
 	return err;
 }
 EXPORT_SYMBOL(mdiobus_write);