2 files changed, 73 insertions, 0 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
index fd8a217556a1..ec632e666c56 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
@@ -20,7 +20,9 @@
 #include <linux/of_net.h>
 #include <linux/phy.h>
 #include <linux/regmap.h>
+#include <linux/reset.h>
 #include <linux/stmmac.h>
+#include "stmmac.h"
 
 #define SYSMGR_EMACGRP_CTRL_PHYSEL_ENUM_GMII_MII 0x0
 #define SYSMGR_EMACGRP_CTRL_PHYSEL_ENUM_RGMII 0x1
@@ -34,6 +36,7 @@ struct socfpga_dwmac {
         u32     reg_shift;
         struct  device *dev;
         struct regmap *sys_mgr_base_addr;
+        struct reset_control *stmmac_rst;
 };
 
 static int socfpga_dwmac_parse_data(struct socfpga_dwmac *dwmac, struct device *dev)
@@ -43,6 +46,13 @@ static int socfpga_dwmac_parse_data(struct socfpga_dwmac *dwmac, struct device *
         u32 reg_offset, reg_shift;
         int ret;
 
+        dwmac->stmmac_rst = devm_reset_control_get(dev,
+                                                  STMMAC_RESOURCE_NAME);
+        if (IS_ERR(dwmac->stmmac_rst)) {
+                dev_info(dev, "Could not get reset control!\n");
+                return -EINVAL;
+        }
+
         dwmac->interface = of_get_phy_mode(np);
 
         sys_mgr_base_addr = syscon_regmap_lookup_by_phandle(np, "altr,sysmgr-syscon");
@@ -125,6 +135,65 @@ static void *socfpga_dwmac_probe(struct platform_device *pdev)
         return dwmac;
 }
 
+static void socfpga_dwmac_exit(struct platform_device *pdev, void *priv)
+{
+        struct socfpga_dwmac    *dwmac = priv;
+
+        /* On socfpga platform exit, assert and hold reset to the
+         * enet controller - the default state after a hard reset.
+         */
+        if (dwmac->stmmac_rst)
+                reset_control_assert(dwmac->stmmac_rst);
+}
+
+static int socfpga_dwmac_init(struct platform_device *pdev, void *priv)
+{
+        struct socfpga_dwmac    *dwmac = priv;
+        struct net_device *ndev = platform_get_drvdata(pdev);
+        struct stmmac_priv *stpriv = NULL;
+        int ret = 0;
+
+        if (ndev)
+                stpriv = netdev_priv(ndev);
+
+        /* Assert reset to the enet controller before changing the phy mode */
+        if (dwmac->stmmac_rst)
+                reset_control_assert(dwmac->stmmac_rst);
+
+        /* Setup the phy mode in the system manager registers according to
+         * devicetree configuration
+         */
+        ret = socfpga_dwmac_setup(dwmac);
+
+        /* Deassert reset for the phy configuration to be sampled by
+         * the enet controller, and operation to start in requested mode
+         */
+        if (dwmac->stmmac_rst)
+                reset_control_deassert(dwmac->stmmac_rst);
+
+        /* Before the enet controller is suspended, the phy is suspended.
+         * This causes the phy clock to be gated. The enet controller is
+         * resumed before the phy, so the clock is still gated "off" when
+         * the enet controller is resumed. This code makes sure the phy
+         * is "resumed" before reinitializing the enet controller since
+         * the enet controller depends on an active phy clock to complete
+         * a DMA reset. A DMA reset will "time out" if executed
+         * with no phy clock input on the Synopsys enet controller.
+         * Verified through Synopsys Case #8000711656.
+         *
+         * Note that the phy clock is also gated when the phy is isolated.
+         * Phy "suspend" and "isolate" controls are located in phy basic
+         * control register 0, and can be modified by the phy driver
+         * framework.
+         */
+        if (stpriv && stpriv->phydev)
+                phy_resume(stpriv->phydev);
+
+        return ret;
+}
+
 const struct stmmac_of_data socfpga_gmac_data = {
         .setup = socfpga_dwmac_probe,
+        .init = socfpga_dwmac_init,
+        .exit = socfpga_dwmac_exit,
 };
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 057a1208e594..18315f34938b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2878,6 +2878,10 @@ int stmmac_suspend(struct net_device *ndev)
                 clk_disable_unprepare(priv->stmmac_clk);
         }
         spin_unlock_irqrestore(&priv->lock, flags);
+
+        priv->oldlink = 0;
+        priv->speed = 0;
+        priv->oldduplex = -1;
         return 0;
 }