3 files changed, 56 insertions, 2 deletions

diff --git a/Documentation/devicetree/bindings/net/stmmac.txt b/Documentation/devicetree/bindings/net/stmmac.txt
index e1ddfcc46a4e..261c563b5f06 100644
--- a/Documentation/devicetree/bindings/net/stmmac.txt
+++ b/Documentation/devicetree/bindings/net/stmmac.txt
@@ -13,6 +13,12 @@ Required properties:
 - phy-mode: String, operation mode of the PHY interface.
   Supported values are: "mii", "rmii", "gmii", "rgmii".
 - snps,phy-addr         phy address to connect to.
+- snps,reset-gpio       gpio number for phy reset.
+- snps,reset-active-low boolean flag to indicate if phy reset is active low.
+- snps,reset-delays-us  is triplet of delays
+        The 1st cell is reset pre-delay in micro seconds.
+        The 2nd cell is reset pulse in micro seconds.
+        The 3rd cell is reset post-delay in micro seconds.
 - snps,pbl              Programmable Burst Length
 - snps,fixed-burst      Program the DMA to use the fixed burst mode
 - snps,mixed-burst      Program the DMA to use the mixed burst mode
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
index cc15039eaa47..fe7bc9903867 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
@@ -27,6 +27,9 @@
 #include <linux/mii.h>
 #include <linux/phy.h>
 #include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+
 #include <asm/io.h>
 
 #include "stmmac.h"
@@ -131,10 +134,46 @@ static int stmmac_mdio_reset(struct mii_bus *bus)
         struct net_device *ndev = bus->priv;
         struct stmmac_priv *priv = netdev_priv(ndev);
         unsigned int mii_address = priv->hw->mii.addr;
+        struct stmmac_mdio_bus_data *data = priv->plat->mdio_bus_data;
+
+#ifdef CONFIG_OF
+        if (priv->device->of_node) {
+                int reset_gpio, active_low;
+
+                if (data->reset_gpio < 0) {
+                        struct device_node *np = priv->device->of_node;
+                        if (!np)
+                                return 0;
+
+                        data->reset_gpio = of_get_named_gpio(np,
+                                                "snps,reset-gpio", 0);
+                        if (data->reset_gpio < 0)
+                                return 0;
+
+                        data->active_low = of_property_read_bool(np,
+                                                "snps,reset-active-low");
+                        of_property_read_u32_array(np,
+                                "snps,reset-delays-us", data->delays, 3);
+                }
+
+                reset_gpio = data->reset_gpio;
+                active_low = data->active_low;
+
+                if (!gpio_request(reset_gpio, "mdio-reset")) {
+                        gpio_direction_output(reset_gpio, active_low ? 1 : 0);
+                        udelay(data->delays[0]);
+                        gpio_set_value(reset_gpio, active_low ? 0 : 1);
+                        udelay(data->delays[1]);
+                        gpio_set_value(reset_gpio, active_low ? 1 : 0);
+                        udelay(data->delays[2]);
+                        gpio_free(reset_gpio);
+                }
+        }
+#endif
 
-        if (priv->plat->mdio_bus_data->phy_reset) {
+        if (data->phy_reset) {
                 pr_debug("stmmac_mdio_reset: calling phy_reset\n");
-                priv->plat->mdio_bus_data->phy_reset(priv->plat->bsp_priv);
+                data->phy_reset(priv->plat->bsp_priv);
         }
 
         /* This is a workaround for problems with the STE101P PHY.
@@ -172,6 +211,11 @@ int stmmac_mdio_register(struct net_device *ndev)
         else
                 irqlist = priv->mii_irq;
 
+#ifdef CONFIG_OF
+        if (priv->device->of_node)
+                mdio_bus_data->reset_gpio = -1;
+#endif
+
         new_bus->name = "stmmac";
         new_bus->read = &stmmac_mdio_read;
         new_bus->write = &stmmac_mdio_write;
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index c1b3ed3fb787..9e495d31516e 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -80,6 +80,10 @@ struct stmmac_mdio_bus_data {
         unsigned int phy_mask;
         int *irqs;
         int probed_phy_irq;
+#ifdef CONFIG_OF
+        int reset_gpio, active_low;
+        u32 delays[3];
+#endif
 };
 
 struct stmmac_dma_cfg {