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 <linux/of.h>
  31 #include <linux/of_gpio.h>
  32
  33 #include <asm/io.h>
  34
  35 #include "stmmac.h"
  36
  37 #define MII_BUSY 0x00000001
  38 #define MII_WRITE 0x00000002
  39
  40 static int stmmac_mdio_busy_wait(void __iomem *ioaddr, unsigned int mii_addr)
  41 {
  42         unsigned long curr;
  43         unsigned long finish = jiffies + 3 * HZ;
  44
  45         do {
  46                 curr = jiffies;
  47                 if (readl(ioaddr + mii_addr) & MII_BUSY)
  48                         cpu_relax();
  49                 else
  50                         return 0;
  51         } while (!time_after_eq(curr, finish));
  52
  53         return -EBUSY;
  54 }
  55
  56 /**
  57  * stmmac_mdio_read
  58  * @bus: points to the mii_bus structure
  59  * @phyaddr: MII addr reg bits 15-11
  60  * @phyreg: MII addr reg bits 10-6
  61  * Description: it reads data from the MII register from within the phy device.
  62  * For the 7111 GMAC, we must set the bit 0 in the MII address register while
  63  * accessing the PHY registers.
  64  * Fortunately, it seems this has no drawback for the 7109 MAC.
  65  */
  66 static int stmmac_mdio_read(struct mii_bus *bus, int phyaddr, int phyreg)
  67 {
  68         struct net_device *ndev = bus->priv;
  69         struct stmmac_priv *priv = netdev_priv(ndev);
  70         unsigned int mii_address = priv->hw->mii.addr;
  71         unsigned int mii_data = priv->hw->mii.data;
  72
  73         int data;
  74         u16 regValue = (((phyaddr << 11) & (0x0000F800)) |
  75                         ((phyreg << 6) & (0x000007C0)));
  76         regValue |= MII_BUSY | ((priv->clk_csr & 0xF) << 2);
  77
  78         if (stmmac_mdio_busy_wait(priv->ioaddr, mii_address))
  79                 return -EBUSY;
  80
  81         writel(regValue, priv->ioaddr + mii_address);
  82
  83         if (stmmac_mdio_busy_wait(priv->ioaddr, mii_address))
  84                 return -EBUSY;
  85
  86         /* Read the data from the MII data register */
  87         data = (int)readl(priv->ioaddr + mii_data);
  88
  89         return data;
  90 }
  91
  92 /**
  93  * stmmac_mdio_write
  94  * @bus: points to the mii_bus structure
  95  * @phyaddr: MII addr reg bits 15-11
  96  * @phyreg: MII addr reg bits 10-6
  97  * @phydata: phy data
  98  * Description: it writes the data into the MII register from within the device.
  99  */
 100 static int stmmac_mdio_write(struct mii_bus *bus, int phyaddr, int phyreg,
 101                              u16 phydata)
 102 {
 103         struct net_device *ndev = bus->priv;
 104         struct stmmac_priv *priv = netdev_priv(ndev);
 105         unsigned int mii_address = priv->hw->mii.addr;
 106         unsigned int mii_data = priv->hw->mii.data;
 107
 108         u16 value =
 109             (((phyaddr << 11) & (0x0000F800)) | ((phyreg << 6) & (0x000007C0)))
 110             | MII_WRITE;
 111
 112         value |= MII_BUSY | ((priv->clk_csr & 0xF) << 2);
 113
 114         /* Wait until any existing MII operation is complete */
 115         if (stmmac_mdio_busy_wait(priv->ioaddr, mii_address))
 116                 return -EBUSY;
 117
 118         /* Set the MII address register to write */
 119         writel(phydata, priv->ioaddr + mii_data);
 120         writel(value, priv->ioaddr + mii_address);
 121
 122         /* Wait until any existing MII operation is complete */
 123         return stmmac_mdio_busy_wait(priv->ioaddr, mii_address);
 124 }
 125
 126 /**
 127  * stmmac_mdio_reset
 128  * @bus: points to the mii_bus structure
 129  * Description: reset the MII bus
 130  */
 131 int stmmac_mdio_reset(struct mii_bus *bus)
 132 {
 133 #if defined(CONFIG_STMMAC_PLATFORM)
 134         struct net_device *ndev = bus->priv;
 135         struct stmmac_priv *priv = netdev_priv(ndev);
 136         unsigned int mii_address = priv->hw->mii.addr;
 137         struct stmmac_mdio_bus_data *data = priv->plat->mdio_bus_data;
 138
 139 #ifdef CONFIG_OF
 140         if (priv->device->of_node) {
 141                 int reset_gpio, active_low;
 142
 143                 if (data->reset_gpio < 0) {
 144                         struct device_node *np = priv->device->of_node;
 145                         if (!np)
 146                                 return 0;
 147
 148                         data->reset_gpio = of_get_named_gpio(np,
 149                                                 "snps,reset-gpio", 0);
 150                         if (data->reset_gpio < 0)
 151                                 return 0;
 152
 153                         data->active_low = of_property_read_bool(np,
 154                                                 "snps,reset-active-low");
 155                         of_property_read_u32_array(np,
 156                                 "snps,reset-delays-us", data->delays, 3);
 157                 }
 158
 159                 reset_gpio = data->reset_gpio;
 160                 active_low = data->active_low;
 161
 162                 if (!gpio_request(reset_gpio, "mdio-reset")) {
 163                         gpio_direction_output(reset_gpio, active_low ? 1 : 0);
 164                         if (data->delays[0])
 165                                 msleep(DIV_ROUND_UP(data->delays[0], 1000));
 166
 167                         gpio_set_value(reset_gpio, active_low ? 0 : 1);
 168                         if (data->delays[1])
 169                                 msleep(DIV_ROUND_UP(data->delays[1], 1000));
 170
 171                         gpio_set_value(reset_gpio, active_low ? 1 : 0);
 172                         if (data->delays[2])
 173                                 msleep(DIV_ROUND_UP(data->delays[2], 1000));
 174                 }
 175         }
 176 #endif
 177
 178         if (data->phy_reset) {
 179                 pr_debug("stmmac_mdio_reset: calling phy_reset\n");
 180                 data->phy_reset(priv->plat->bsp_priv);
 181         }
 182
 183         /* This is a workaround for problems with the STE101P PHY.
 184          * It doesn't complete its reset until at least one clock cycle
 185          * on MDC, so perform a dummy mdio read.
 186          */
 187         writel(0, priv->ioaddr + mii_address);
 188 #endif
 189         return 0;
 190 }
 191
 192 /**
 193  * stmmac_mdio_register
 194  * @ndev: net device structure
 195  * Description: it registers the MII bus
 196  */
 197 int stmmac_mdio_register(struct net_device *ndev)
 198 {
 199         int err = 0;
 200         struct mii_bus *new_bus;
 201         int *irqlist;
 202         struct stmmac_priv *priv = netdev_priv(ndev);
 203         struct stmmac_mdio_bus_data *mdio_bus_data = priv->plat->mdio_bus_data;
 204         int addr, found;
 205
 206         if (!mdio_bus_data)
 207                 return 0;
 208
 209         new_bus = mdiobus_alloc();
 210         if (new_bus == NULL)
 211                 return -ENOMEM;
 212
 213         if (mdio_bus_data->irqs) {
 214                 irqlist = mdio_bus_data->irqs;
 215         } else {
 216                 for (addr = 0; addr < PHY_MAX_ADDR; addr++)
 217                         priv->mii_irq[addr] = PHY_POLL;
 218                 irqlist = priv->mii_irq;
 219         }
 220
 221 #ifdef CONFIG_OF
 222         if (priv->device->of_node)
 223                 mdio_bus_data->reset_gpio = -1;
 224 #endif
 225
 226         new_bus->name = "stmmac";
 227         new_bus->read = &stmmac_mdio_read;
 228         new_bus->write = &stmmac_mdio_write;
 229         new_bus->reset = &stmmac_mdio_reset;
 230         snprintf(new_bus->id, MII_BUS_ID_SIZE, "%s-%x",
 231                  new_bus->name, priv->plat->bus_id);
 232         new_bus->priv = ndev;
 233         new_bus->irq = irqlist;
 234         new_bus->phy_mask = mdio_bus_data->phy_mask;
 235         new_bus->parent = priv->device;
 236         err = mdiobus_register(new_bus);
 237         if (err != 0) {
 238                 pr_err("%s: Cannot register as MDIO bus\n", new_bus->name);
 239                 goto bus_register_fail;
 240         }
 241
 242         found = 0;
 243         for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
 244                 struct phy_device *phydev = new_bus->phy_map[addr];
 245                 if (phydev) {
 246                         int act = 0;
 247                         char irq_num[4];
 248                         char *irq_str;
 249
 250                         /*
 251                          * If an IRQ was provided to be assigned after
 252                          * the bus probe, do it here.
 253                          */
 254                         if ((mdio_bus_data->irqs == NULL) &&
 255                             (mdio_bus_data->probed_phy_irq > 0)) {
 256                                 irqlist[addr] = mdio_bus_data->probed_phy_irq;
 257                                 phydev->irq = mdio_bus_data->probed_phy_irq;
 258                         }
 259
 260                         /*
 261                          * If we're going to bind the MAC to this PHY bus,
 262                          * and no PHY number was provided to the MAC,
 263                          * use the one probed here.
 264                          */
 265                         if (priv->plat->phy_addr == -1)
 266                                 priv->plat->phy_addr = addr;
 267
 268                         act = (priv->plat->phy_addr == addr);
 269                         switch (phydev->irq) {
 270                         case PHY_POLL:
 271                                 irq_str = "POLL";
 272                                 break;
 273                         case PHY_IGNORE_INTERRUPT:
 274                                 irq_str = "IGNORE";
 275                                 break;
 276                         default:
 277                                 sprintf(irq_num, "%d", phydev->irq);
 278                                 irq_str = irq_num;
 279                                 break;
 280                         }
 281                         pr_info("%s: PHY ID %08x at %d IRQ %s (%s)%s\n",
 282                                 ndev->name, phydev->phy_id, addr,
 283                                 irq_str, dev_name(&phydev->dev),
 284                                 act ? " active" : "");
 285                         found = 1;
 286                 }
 287         }
 288
 289         if (!found) {
 290                 pr_warn("%s: No PHY found\n", ndev->name);
 291                 mdiobus_unregister(new_bus);
 292                 mdiobus_free(new_bus);
 293                 return -ENODEV;
 294         }
 295
 296         priv->mii = new_bus;
 297
 298         return 0;
 299
 300 bus_register_fail:
 301         mdiobus_free(new_bus);
 302         return err;
 303 }
 304
 305 /**
 306  * stmmac_mdio_unregister
 307  * @ndev: net device structure
 308  * Description: it unregisters the MII bus
 309  */
 310 int stmmac_mdio_unregister(struct net_device *ndev)
 311 {
 312         struct stmmac_priv *priv = netdev_priv(ndev);
 313
 314         if (!priv->mii)
 315                 return 0;
 316
 317         mdiobus_unregister(priv->mii);
 318         priv->mii->priv = NULL;
 319         mdiobus_free(priv->mii);
 320         priv->mii = NULL;
 321
 322         return 0;
 323 }