drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c

   1 /*******************************************************************************
   2   STMMAC Ethernet Driver -- MDIO bus implementation
   3   Provides Bus interface for MII registers
   4
   5   Copyright (C) 2007-2009  STMicroelectronics Ltd
   6
   7   This program is free software; you can redistribute it and/or modify it
   8   under the terms and conditions of the GNU General Public License,
   9   version 2, as published by the Free Software Foundation.
  10
  11   This program is distributed in the hope it will be useful, but WITHOUT
  12   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14   more details.
  15
  16   You should have received a copy of the GNU General Public License along with
  17   this program; if not, write to the Free Software Foundation, Inc.,
  18   51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  19
  20   The full GNU General Public License is included in this distribution in
  21   the file called "COPYING".
  22
  23   Author: Carl Shaw <carl.shaw@st.com>
  24   Maintainer: Giuseppe Cavallaro <peppe.cavallaro@st.com>
  25 *******************************************************************************/
  26
  27 #include <linux/mii.h>
  28 #include <linux/phy.h>
  29 #include <linux/slab.h>
  30 #include <asm/io.h>
  31
  32 #include "stmmac.h"
  33
  34 #define MII_BUSY 0x00000001
  35 #define MII_WRITE 0x00000002
  36
  37 static int stmmac_mdio_busy_wait(void __iomem *ioaddr, unsigned int mii_addr)
  38 {
  39         unsigned long curr;
  40         unsigned long finish = jiffies + 3 * HZ;
  41
  42         do {
  43                 curr = jiffies;
  44                 if (readl(ioaddr + mii_addr) & MII_BUSY)
  45                         cpu_relax();
  46                 else
  47                         return 0;
  48         } while (!time_after_eq(curr, finish));
  49
  50         return -EBUSY;
  51 }
  52
  53 /**
  54  * stmmac_mdio_read
  55  * @bus: points to the mii_bus structure
  56  * @phyaddr: MII addr reg bits 15-11
  57  * @phyreg: MII addr reg bits 10-6
  58  * Description: it reads data from the MII register from within the phy device.
  59  * For the 7111 GMAC, we must set the bit 0 in the MII address register while
  60  * accessing the PHY registers.
  61  * Fortunately, it seems this has no drawback for the 7109 MAC.
  62  */
  63 static int stmmac_mdio_read(struct mii_bus *bus, int phyaddr, int phyreg)
  64 {
  65         struct net_device *ndev = bus->priv;
  66         struct stmmac_priv *priv = netdev_priv(ndev);
  67         unsigned int mii_address = priv->hw->mii.addr;
  68         unsigned int mii_data = priv->hw->mii.data;
  69
  70         int data;
  71         u16 regValue = (((phyaddr << 11) & (0x0000F800)) |
  72                         ((phyreg << 6) & (0x000007C0)));
  73         regValue |= MII_BUSY | ((priv->clk_csr & 0xF) << 2);
  74
  75         if (stmmac_mdio_busy_wait(priv->ioaddr, mii_address))
  76                 return -EBUSY;
  77
  78         writel(regValue, priv->ioaddr + mii_address);
  79
  80         if (stmmac_mdio_busy_wait(priv->ioaddr, mii_address))
  81                 return -EBUSY;
  82
  83         /* Read the data from the MII data register */
  84         data = (int)readl(priv->ioaddr + mii_data);
  85
  86         return data;
  87 }
  88
  89 /**
  90  * stmmac_mdio_write
  91  * @bus: points to the mii_bus structure
  92  * @phyaddr: MII addr reg bits 15-11
  93  * @phyreg: MII addr reg bits 10-6
  94  * @phydata: phy data
  95  * Description: it writes the data into the MII register from within the device.
  96  */
  97 static int stmmac_mdio_write(struct mii_bus *bus, int phyaddr, int phyreg,
  98                              u16 phydata)
  99 {
 100         struct net_device *ndev = bus->priv;
 101         struct stmmac_priv *priv = netdev_priv(ndev);
 102         unsigned int mii_address = priv->hw->mii.addr;
 103         unsigned int mii_data = priv->hw->mii.data;
 104
 105         u16 value =
 106             (((phyaddr << 11) & (0x0000F800)) | ((phyreg << 6) & (0x000007C0)))
 107             | MII_WRITE;
 108
 109         value |= MII_BUSY | ((priv->clk_csr & 0xF) << 2);
 110
 111         /* Wait until any existing MII operation is complete */
 112         if (stmmac_mdio_busy_wait(priv->ioaddr, mii_address))
 113                 return -EBUSY;
 114
 115         /* Set the MII address register to write */
 116         writel(phydata, priv->ioaddr + mii_data);
 117         writel(value, priv->ioaddr + mii_address);
 118
 119         /* Wait until any existing MII operation is complete */
 120         return stmmac_mdio_busy_wait(priv->ioaddr, mii_address);
 121 }
 122
 123 /**
 124  * stmmac_mdio_reset
 125  * @bus: points to the mii_bus structure
 126  * Description: reset the MII bus
 127  */
 128 static int stmmac_mdio_reset(struct mii_bus *bus)
 129 {
 130 #if defined(CONFIG_STMMAC_PLATFORM)
 131         struct net_device *ndev = bus->priv;
 132         struct stmmac_priv *priv = netdev_priv(ndev);
 133         unsigned int mii_address = priv->hw->mii.addr;
 134
 135         if (priv->plat->mdio_bus_data->phy_reset) {
 136                 pr_debug("stmmac_mdio_reset: calling phy_reset\n");
 137                 priv->plat->mdio_bus_data->phy_reset(priv->plat->bsp_priv);
 138         }
 139
 140         /* This is a workaround for problems with the STE101P PHY.
 141          * It doesn't complete its reset until at least one clock cycle
 142          * on MDC, so perform a dummy mdio read.
 143          */
 144         writel(0, priv->ioaddr + mii_address);
 145 #endif
 146         return 0;
 147 }
 148
 149 /**
 150  * stmmac_mdio_register
 151  * @ndev: net device structure
 152  * Description: it registers the MII bus
 153  */
 154 int stmmac_mdio_register(struct net_device *ndev)
 155 {
 156         int err = 0;
 157         struct mii_bus *new_bus;
 158         int *irqlist;
 159         struct stmmac_priv *priv = netdev_priv(ndev);
 160         struct stmmac_mdio_bus_data *mdio_bus_data = priv->plat->mdio_bus_data;
 161         int addr, found;
 162
 163         if (!mdio_bus_data)
 164                 return 0;
 165
 166         new_bus = mdiobus_alloc();
 167         if (new_bus == NULL)
 168                 return -ENOMEM;
 169
 170         if (mdio_bus_data->irqs)
 171                 irqlist = mdio_bus_data->irqs;
 172         else
 173                 irqlist = priv->mii_irq;
 174
 175         new_bus->name = "stmmac";
 176         new_bus->read = &stmmac_mdio_read;
 177         new_bus->write = &stmmac_mdio_write;
 178         new_bus->reset = &stmmac_mdio_reset;
 179         snprintf(new_bus->id, MII_BUS_ID_SIZE, "%s-%x",
 180                 new_bus->name, mdio_bus_data->bus_id);
 181         new_bus->priv = ndev;
 182         new_bus->irq = irqlist;
 183         new_bus->phy_mask = mdio_bus_data->phy_mask;
 184         new_bus->parent = priv->device;
 185         err = mdiobus_register(new_bus);
 186         if (err != 0) {
 187                 pr_err("%s: Cannot register as MDIO bus\n", new_bus->name);
 188                 goto bus_register_fail;
 189         }
 190
 191         priv->mii = new_bus;
 192
 193         found = 0;
 194         for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
 195                 struct phy_device *phydev = new_bus->phy_map[addr];
 196                 if (phydev) {
 197                         int act = 0;
 198                         char irq_num[4];
 199                         char *irq_str;
 200
 201                         /*
 202                          * If an IRQ was provided to be assigned after
 203                          * the bus probe, do it here.
 204                          */
 205                         if ((mdio_bus_data->irqs == NULL) &&
 206                             (mdio_bus_data->probed_phy_irq > 0)) {
 207                                 irqlist[addr] = mdio_bus_data->probed_phy_irq;
 208                                 phydev->irq = mdio_bus_data->probed_phy_irq;
 209                         }
 210
 211                         /*
 212                          * If we're  going to bind the MAC to this PHY bus,
 213                          * and no PHY number was provided to the MAC,
 214                          * use the one probed here.
 215                          */
 216                         if ((priv->plat->bus_id == mdio_bus_data->bus_id) &&
 217                             (priv->plat->phy_addr == -1))
 218                                 priv->plat->phy_addr = addr;
 219
 220                         act = (priv->plat->bus_id == mdio_bus_data->bus_id) &&
 221                                 (priv->plat->phy_addr == addr);
 222                         switch (phydev->irq) {
 223                         case PHY_POLL:
 224                                 irq_str = "POLL";
 225                                 break;
 226                         case PHY_IGNORE_INTERRUPT:
 227                                 irq_str = "IGNORE";
 228                                 break;
 229                         default:
 230                                 sprintf(irq_num, "%d", phydev->irq);
 231                                 irq_str = irq_num;
 232                                 break;
 233                         }
 234                         pr_info("%s: PHY ID %08x at %d IRQ %s (%s)%s\n",
 235                                 ndev->name, phydev->phy_id, addr,
 236                                 irq_str, dev_name(&phydev->dev),
 237                                 act ? " active" : "");
 238                         found = 1;
 239                 }
 240         }
 241
 242         if (!found)
 243                 pr_warning("%s: No PHY found\n", ndev->name);
 244
 245         return 0;
 246
 247 bus_register_fail:
 248         mdiobus_free(new_bus);
 249         return err;
 250 }
 251
 252 /**
 253  * stmmac_mdio_unregister
 254  * @ndev: net device structure
 255  * Description: it unregisters the MII bus
 256  */
 257 int stmmac_mdio_unregister(struct net_device *ndev)
 258 {
 259         struct stmmac_priv *priv = netdev_priv(ndev);
 260
 261         mdiobus_unregister(priv->mii);
 262         priv->mii->priv = NULL;
 263         mdiobus_free(priv->mii);
 264         priv->mii = NULL;
 265
 266         return 0;
 267 }