UPSTREAM: net: arc_emac: support the phy reset for emac driver

This patch adds to support the emac phy reset.

Different boards may require different phy reset duration. Add property
phy-reset-duration for emac driver, so that the boards that need
a longer reset duration can specify it in their device tree.

Change-Id: I2a3f1b50e685251d4a6d61390c0c6dd63119f134
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Cc: Alexander Kochetkov <al.kochet@gmail.com>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from git.kernel.org next/linux-next.git master
 commit 1bddd96cba03da0a14b3e5144e98c9a6ff17e983)

diff --git a/drivers/net/ethernet/arc/emac.h b/drivers/net/ethernet/arc/emac.h
index dae1ac300a49e692475a587381db629de3b4babc..1a4040397a4bc1b213a37b46744751303750e6b4 100644 (file)
--- a/drivers/net/ethernet/arc/emac.h
+++ b/drivers/net/ethernet/arc/emac.h
@@ -102,6 +102,11 @@ struct buffer_state {
        DEFINE_DMA_UNMAP_LEN(len);
 };
 
+struct arc_emac_mdio_bus_data {
+       struct gpio_desc *reset_gpio;
+       int msec;
+};
+
 /**
  * struct arc_emac_priv - Storage of EMAC's private information.
  * @dev:       Pointer to the current device.
@@ -131,6 +136,7 @@ struct arc_emac_priv {
        struct device *dev;
        struct phy_device *phy_dev;
        struct mii_bus *bus;
+       struct arc_emac_mdio_bus_data bus_data;
 
        void __iomem *regs;
        struct clk *clk;

diff --git a/drivers/net/ethernet/arc/emac_mdio.c b/drivers/net/ethernet/arc/emac_mdio.c
index d5ee986936dadd6764a0fe08ecc3b963c2e97d88..caf704264eba906db6e5376bda4369f7ed8d5281 100644 (file)
--- a/drivers/net/ethernet/arc/emac_mdio.c
+++ b/drivers/net/ethernet/arc/emac_mdio.c
@@ -7,6 +7,7 @@
 #include <linux/delay.h>
 #include <linux/of_mdio.h>
 #include <linux/platform_device.h>
+#include <linux/gpio/consumer.h>
 
 #include "emac.h"
 
@@ -98,6 +99,25 @@ static int arc_mdio_write(struct mii_bus *bus, int phy_addr,
        return arc_mdio_complete_wait(priv);
 }
 
+/**
+ * arc_mdio_reset
+ * @bus: points to the mii_bus structure
+ * Description: reset the MII bus
+ */
+int arc_mdio_reset(struct mii_bus *bus)
+{
+       struct arc_emac_priv *priv = bus->priv;
+       struct arc_emac_mdio_bus_data *data = &priv->bus_data;
+
+       if (data->reset_gpio) {
+               gpiod_set_value_cansleep(data->reset_gpio, 1);
+               msleep(data->msec);
+               gpiod_set_value_cansleep(data->reset_gpio, 0);
+       }
+
+       return 0;
+}
+
 /**
  * arc_mdio_probe - MDIO probe function.
  * @priv:      Pointer to ARC EMAC private data structure.
@@ -109,6 +129,8 @@ static int arc_mdio_write(struct mii_bus *bus, int phy_addr,
  */
 int arc_mdio_probe(struct arc_emac_priv *priv)
 {
+       struct arc_emac_mdio_bus_data *data = &priv->bus_data;
+       struct device_node *np = priv->dev->of_node;
        struct mii_bus *bus;
        int error;
 
@@ -122,6 +144,21 @@ int arc_mdio_probe(struct arc_emac_priv *priv)
        bus->name = "Synopsys MII Bus",
        bus->read = &arc_mdio_read;
        bus->write = &arc_mdio_write;
+       bus->reset = &arc_mdio_reset;
+
+       /* optional reset-related properties */
+       data->reset_gpio = devm_gpiod_get_optional(priv->dev, "phy-reset",
+                                                  GPIOD_OUT_LOW);
+       if (IS_ERR(data->reset_gpio)) {
+               error = PTR_ERR(data->reset_gpio);
+               dev_err(priv->dev, "Failed to request gpio: %d\n", error);
+               return error;
+       }
+
+       of_property_read_u32(np, "phy-reset-duration", &data->msec);
+       /* A sane reset duration should not be longer than 1s */
+       if (data->msec > 1000)
+               data->msec = 1;
 
        snprintf(bus->id, MII_BUS_ID_SIZE, "%s", bus->name);