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 #include <linux/of_mdio.h>
  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
 142                 if (data->reset_gpio < 0) {
 143                         struct device_node *np = priv->device->of_node;
 144                         if (!np)
 145                                 return 0;
 146
 147                         data->reset_gpio = of_get_named_gpio(np,
 148                                                 "snps,reset-gpio", 0);
 149                         if (data->reset_gpio < 0)
 150                                 return 0;
 151
 152                         data->active_low = of_property_read_bool(np,
 153                                                 "snps,reset-active-low");
 154                         of_property_read_u32_array(np,
 155                                 "snps,reset-delays-us", data->delays, 3);
 156
 157                         if (gpio_request(data->reset_gpio, "mdio-reset"))
 158                                 return 0;
 159                 }
 160
 161                 gpio_direction_output(data->reset_gpio,
 162                                       data->active_low ? 1 : 0);
 163                 if (data->delays[0])
 164                         msleep(DIV_ROUND_UP(data->delays[0], 1000));
 165
 166                 gpio_set_value(data->reset_gpio, data->active_low ? 0 : 1);
 167                 if (data->delays[1])
 168                         msleep(DIV_ROUND_UP(data->delays[1], 1000));
 169
 170                 gpio_set_value(data->reset_gpio, data->active_low ? 1 : 0);
 171                 if (data->delays[2])
 172                         msleep(DIV_ROUND_UP(data->delays[2], 1000));
 173         }
 174 #endif
 175
 176         if (data->phy_reset) {
 177                 pr_debug("stmmac_mdio_reset: calling phy_reset\n");
 178                 data->phy_reset(priv->plat->bsp_priv);
 179         }
 180
 181         /* This is a workaround for problems with the STE101P PHY.
 182          * It doesn't complete its reset until at least one clock cycle
 183          * on MDC, so perform a dummy mdio read.
 184          */
 185         writel(0, priv->ioaddr + mii_address);
 186 #endif
 187         return 0;
 188 }
 189
 190 /**
 191  * stmmac_mdio_register
 192  * @ndev: net device structure
 193  * Description: it registers the MII bus
 194  */
 195 int stmmac_mdio_register(struct net_device *ndev)
 196 {
 197         int err = 0;
 198         struct mii_bus *new_bus;
 199         struct stmmac_priv *priv = netdev_priv(ndev);
 200         struct stmmac_mdio_bus_data *mdio_bus_data = priv->plat->mdio_bus_data;
 201         int addr, found;
 202         struct device_node *mdio_node = priv->plat->mdio_node;
 203
 204         if (!mdio_bus_data)
 205                 return 0;
 206
 207         if (IS_ENABLED(CONFIG_OF)) {
 208                 if (mdio_node) {
 209                         netdev_dbg(ndev, "FOUND MDIO subnode\n");
 210                 } else {
 211                         netdev_warn(ndev, "No MDIO subnode found\n");
 212                 }
 213         }
 214
 215         new_bus = mdiobus_alloc();
 216         if (new_bus == NULL)
 217                 return -ENOMEM;
 218
 219         if (mdio_bus_data->irqs)
 220                 memcpy(new_bus->irq, mdio_bus_data, sizeof(new_bus->irq));
 221
 222 #ifdef CONFIG_OF
 223         if (priv->device->of_node)
 224                 mdio_bus_data->reset_gpio = -1;
 225 #endif
 226
 227         new_bus->name = "stmmac";
 228         new_bus->read = &stmmac_mdio_read;
 229         new_bus->write = &stmmac_mdio_write;
 230         new_bus->reset = &stmmac_mdio_reset;
 231         snprintf(new_bus->id, MII_BUS_ID_SIZE, "%s-%x",
 232                  new_bus->name, priv->plat->bus_id);
 233         new_bus->priv = ndev;
 234         new_bus->phy_mask = mdio_bus_data->phy_mask;
 235         new_bus->parent = priv->device;
 236
 237         if (mdio_node)
 238                 err = of_mdiobus_register(new_bus, mdio_node);
 239         else
 240                 err = mdiobus_register(new_bus);
 241         if (err != 0) {
 242                 pr_err("%s: Cannot register as MDIO bus\n", new_bus->name);
 243                 goto bus_register_fail;
 244         }
 245
 246         if (priv->plat->phy_node || mdio_node)
 247                 goto bus_register_done;
 248
 249         found = 0;
 250         for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
 251                 struct phy_device *phydev = mdiobus_get_phy(new_bus, addr);
 252                 if (phydev) {
 253                         int act = 0;
 254                         char irq_num[4];
 255                         char *irq_str;
 256
 257                         /*
 258                          * If an IRQ was provided to be assigned after
 259                          * the bus probe, do it here.
 260                          */
 261                         if ((mdio_bus_data->irqs == NULL) &&
 262                             (mdio_bus_data->probed_phy_irq > 0)) {
 263                                 new_bus->irq[addr] =
 264                                         mdio_bus_data->probed_phy_irq;
 265                                 phydev->irq = mdio_bus_data->probed_phy_irq;
 266                         }
 267
 268                         /*
 269                          * If we're going to bind the MAC to this PHY bus,
 270                          * and no PHY number was provided to the MAC,
 271                          * use the one probed here.
 272                          */
 273                         if (priv->plat->phy_addr == -1)
 274                                 priv->plat->phy_addr = addr;
 275
 276                         act = (priv->plat->phy_addr == addr);
 277                         switch (phydev->irq) {
 278                         case PHY_POLL:
 279                                 irq_str = "POLL";
 280                                 break;
 281                         case PHY_IGNORE_INTERRUPT:
 282                                 irq_str = "IGNORE";
 283                                 break;
 284                         default:
 285                                 sprintf(irq_num, "%d", phydev->irq);
 286                                 irq_str = irq_num;
 287                                 break;
 288                         }
 289                         pr_info("%s: PHY ID %08x at %d IRQ %s (%s)%s\n",
 290                                 ndev->name, phydev->phy_id, addr,
 291                                 irq_str, phydev_name(phydev),
 292                                 act ? " active" : "");
 293                         found = 1;
 294                 }
 295         }
 296
 297         if (!found && !mdio_node) {
 298                 pr_warn("%s: No PHY found\n", ndev->name);
 299                 mdiobus_unregister(new_bus);
 300                 mdiobus_free(new_bus);
 301                 return -ENODEV;
 302         }
 303
 304 bus_register_done:
 305         priv->mii = new_bus;
 306
 307         return 0;
 308
 309 bus_register_fail:
 310         mdiobus_free(new_bus);
 311         return err;
 312 }
 313
 314 /**
 315  * stmmac_mdio_unregister
 316  * @ndev: net device structure
 317  * Description: it unregisters the MII bus
 318  */
 319 int stmmac_mdio_unregister(struct net_device *ndev)
 320 {
 321         struct stmmac_priv *priv = netdev_priv(ndev);
 322
 323         if (!priv->mii)
 324                 return 0;
 325
 326         mdiobus_unregister(priv->mii);
 327         priv->mii->priv = NULL;
 328         mdiobus_free(priv->mii);
 329         priv->mii = NULL;
 330
 331         return 0;
 332 }