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path: root/drivers/net/ethernet/arc/emac_mdio.c
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Diffstat (limited to 'drivers/net/ethernet/arc/emac_mdio.c')
-rw-r--r--drivers/net/ethernet/arc/emac_mdio.c152
1 files changed, 152 insertions, 0 deletions
diff --git a/drivers/net/ethernet/arc/emac_mdio.c b/drivers/net/ethernet/arc/emac_mdio.c
new file mode 100644
index 0000000..26ba242
--- /dev/null
+++ b/drivers/net/ethernet/arc/emac_mdio.c
@@ -0,0 +1,152 @@
+/*
+ * Copyright (C) 2004-2013 Synopsys, Inc. (www.synopsys.com)
+ *
+ * MDIO implementation for ARC EMAC
+ */
+
+#include <linux/delay.h>
+#include <linux/of_mdio.h>
+#include <linux/platform_device.h>
+
+#include "emac.h"
+
+/* Number of seconds we wait for "MDIO complete" flag to appear */
+#define ARC_MDIO_COMPLETE_POLL_COUNT 1
+
+/**
+ * arc_mdio_complete_wait - Waits until MDIO transaction is completed.
+ * @priv: Pointer to ARC EMAC private data structure.
+ *
+ * returns: 0 on success, -ETIMEDOUT on a timeout.
+ */
+static int arc_mdio_complete_wait(struct arc_emac_priv *priv)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARC_MDIO_COMPLETE_POLL_COUNT * 40; i++) {
+ unsigned int status = arc_reg_get(priv, R_STATUS);
+
+ status &= MDIO_MASK;
+
+ if (status) {
+ /* Reset "MDIO complete" flag */
+ arc_reg_set(priv, R_STATUS, status);
+ return 0;
+ }
+
+ msleep(25);
+ }
+
+ return -ETIMEDOUT;
+}
+
+/**
+ * arc_mdio_read - MDIO interface read function.
+ * @bus: Pointer to MII bus structure.
+ * @phy_addr: Address of the PHY device.
+ * @reg_num: PHY register to read.
+ *
+ * returns: The register contents on success, -ETIMEDOUT on a timeout.
+ *
+ * Reads the contents of the requested register from the requested PHY
+ * address.
+ */
+static int arc_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
+{
+ struct arc_emac_priv *priv = bus->priv;
+ unsigned int value;
+ int error;
+
+ arc_reg_set(priv, R_MDIO,
+ 0x60020000 | (phy_addr << 23) | (reg_num << 18));
+
+ error = arc_mdio_complete_wait(priv);
+ if (error < 0)
+ return error;
+
+ value = arc_reg_get(priv, R_MDIO) & 0xffff;
+
+ dev_dbg(priv->dev, "arc_mdio_read(phy_addr=%i, reg_num=%x) = %x\n",
+ phy_addr, reg_num, value);
+
+ return value;
+}
+
+/**
+ * arc_mdio_write - MDIO interface write function.
+ * @bus: Pointer to MII bus structure.
+ * @phy_addr: Address of the PHY device.
+ * @reg_num: PHY register to write to.
+ * @value: Value to be written into the register.
+ *
+ * returns: 0 on success, -ETIMEDOUT on a timeout.
+ *
+ * Writes the value to the requested register.
+ */
+static int arc_mdio_write(struct mii_bus *bus, int phy_addr,
+ int reg_num, u16 value)
+{
+ struct arc_emac_priv *priv = bus->priv;
+
+ dev_dbg(priv->dev,
+ "arc_mdio_write(phy_addr=%i, reg_num=%x, value=%x)\n",
+ phy_addr, reg_num, value);
+
+ arc_reg_set(priv, R_MDIO,
+ 0x50020000 | (phy_addr << 23) | (reg_num << 18) | value);
+
+ return arc_mdio_complete_wait(priv);
+}
+
+/**
+ * arc_mdio_probe - MDIO probe function.
+ * @pdev: Pointer to platform device.
+ * @priv: Pointer to ARC EMAC private data structure.
+ *
+ * returns: 0 on success, -ENOMEM when mdiobus_alloc
+ * (to allocate memory for MII bus structure) fails.
+ *
+ * Sets up and registers the MDIO interface.
+ */
+int arc_mdio_probe(struct platform_device *pdev, struct arc_emac_priv *priv)
+{
+ struct mii_bus *bus;
+ int error;
+
+ bus = mdiobus_alloc();
+ if (!bus)
+ return -ENOMEM;
+
+ priv->bus = bus;
+ bus->priv = priv;
+ bus->parent = priv->dev;
+ bus->name = "Synopsys MII Bus",
+ bus->read = &arc_mdio_read;
+ bus->write = &arc_mdio_write;
+
+ snprintf(bus->id, MII_BUS_ID_SIZE, "%s", pdev->name);
+
+ error = of_mdiobus_register(bus, pdev->dev.of_node);
+ if (error) {
+ dev_err(priv->dev, "cannot register MDIO bus %s\n", bus->name);
+ mdiobus_free(bus);
+ return error;
+ }
+
+ return 0;
+}
+
+/**
+ * arc_mdio_remove - MDIO remove function.
+ * @priv: Pointer to ARC EMAC private data structure.
+ *
+ * Unregisters the MDIO and frees any associate memory for MII bus.
+ */
+int arc_mdio_remove(struct arc_emac_priv *priv)
+{
+ mdiobus_unregister(priv->bus);
+ mdiobus_free(priv->bus);
+ priv->bus = NULL;
+
+ return 0;
+}
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