drivers/net/ll_temac_mdio.c

   1 /*
   2  * MDIO bus driver for the Xilinx TEMAC device
   3  *
   4  * Copyright (c) 2009 Secret Lab Technologies, Ltd.
   5  */
   6
   7 #include <linux/io.h>
   8 #include <linux/netdevice.h>
   9 #include <linux/mutex.h>
  10 #include <linux/phy.h>
  11 #include <linux/of.h>
  12 #include <linux/of_device.h>
  13 #include <linux/slab.h>
  14 #include <linux/of_mdio.h>
  15
  16 #include "ll_temac.h"
  17
  18 /* ---------------------------------------------------------------------
  19  * MDIO Bus functions
  20  */
  21 static int temac_mdio_read(struct mii_bus *bus, int phy_id, int reg)
  22 {
  23         struct temac_local *lp = bus->priv;
  24         u32 rc;
  25
  26         /* Write the PHY address to the MIIM Access Initiator register.
  27          * When the transfer completes, the PHY register value will appear
  28          * in the LSW0 register */
  29         mutex_lock(&lp->indirect_mutex);
  30         temac_iow(lp, XTE_LSW0_OFFSET, (phy_id << 5) | reg);
  31         rc = temac_indirect_in32(lp, XTE_MIIMAI_OFFSET);
  32         mutex_unlock(&lp->indirect_mutex);
  33
  34         dev_dbg(lp->dev, "temac_mdio_read(phy_id=%i, reg=%x) == %x\n",
  35                 phy_id, reg, rc);
  36
  37         return rc;
  38 }
  39
  40 static int temac_mdio_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
  41 {
  42         struct temac_local *lp = bus->priv;
  43
  44         dev_dbg(lp->dev, "temac_mdio_write(phy_id=%i, reg=%x, val=%x)\n",
  45                 phy_id, reg, val);
  46
  47         /* First write the desired value into the write data register
  48          * and then write the address into the access initiator register
  49          */
  50         mutex_lock(&lp->indirect_mutex);
  51         temac_indirect_out32(lp, XTE_MGTDR_OFFSET, val);
  52         temac_indirect_out32(lp, XTE_MIIMAI_OFFSET, (phy_id << 5) | reg);
  53         mutex_unlock(&lp->indirect_mutex);
  54
  55         return 0;
  56 }
  57
  58 int temac_mdio_setup(struct temac_local *lp, struct device_node *np)
  59 {
  60         struct mii_bus *bus;
  61         const u32 *bus_hz;
  62         int clk_div;
  63         int rc, size;
  64         struct resource res;
  65
  66         /* Calculate a reasonable divisor for the clock rate */
  67         clk_div = 0x3f; /* worst-case default setting */
  68         bus_hz = of_get_property(np, "clock-frequency", &size);
  69         if (bus_hz && size >= sizeof(*bus_hz)) {
  70                 clk_div = (*bus_hz) / (2500 * 1000 * 2) - 1;
  71                 if (clk_div < 1)
  72                         clk_div = 1;
  73                 if (clk_div > 0x3f)
  74                         clk_div = 0x3f;
  75         }
  76
  77         /* Enable the MDIO bus by asserting the enable bit and writing
  78          * in the clock config */
  79         mutex_lock(&lp->indirect_mutex);
  80         temac_indirect_out32(lp, XTE_MC_OFFSET, 1 << 6 | clk_div);
  81         mutex_unlock(&lp->indirect_mutex);
  82
  83         bus = mdiobus_alloc();
  84         if (!bus)
  85                 return -ENOMEM;
  86
  87         of_address_to_resource(np, 0, &res);
  88         snprintf(bus->id, MII_BUS_ID_SIZE, "%.8llx",
  89                  (unsigned long long)res.start);
  90         bus->priv = lp;
  91         bus->name = "Xilinx TEMAC MDIO";
  92         bus->read = temac_mdio_read;
  93         bus->write = temac_mdio_write;
  94         bus->parent = lp->dev;
  95         bus->irq = lp->mdio_irqs; /* preallocated IRQ table */
  96
  97         lp->mii_bus = bus;
  98
  99         rc = of_mdiobus_register(bus, np);
 100         if (rc)
 101                 goto err_register;
 102
 103         mutex_lock(&lp->indirect_mutex);
 104         dev_dbg(lp->dev, "MDIO bus registered;  MC:%x\n",
 105                 temac_indirect_in32(lp, XTE_MC_OFFSET));
 106         mutex_unlock(&lp->indirect_mutex);
 107         return 0;
 108
 109  err_register:
 110         mdiobus_free(bus);
 111         return rc;
 112 }
 113
 114 void temac_mdio_teardown(struct temac_local *lp)
 115 {
 116         mdiobus_unregister(lp->mii_bus);
 117         kfree(lp->mii_bus->irq);
 118         mdiobus_free(lp->mii_bus);
 119         lp->mii_bus = NULL;
 120 }
 121