drivers/net/gianfar_mii.c

   1 /*
   2  * drivers/net/gianfar_mii.c
   3  *
   4  * Gianfar Ethernet Driver -- MIIM bus implementation
   5  * Provides Bus interface for MIIM regs
   6  *
   7  * Author: Andy Fleming
   8  * Maintainer: Kumar Gala
   9  *
  10  * Copyright (c) 2002-2004 Freescale Semiconductor, Inc.
  11  *
  12  * This program is free software; you can redistribute  it and/or modify it
  13  * under  the terms of  the GNU General  Public License as published by the
  14  * Free Software Foundation;  either version 2 of the  License, or (at your
  15  * option) any later version.
  16  *
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/string.h>
  21 #include <linux/errno.h>
  22 #include <linux/unistd.h>
  23 #include <linux/slab.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/init.h>
  26 #include <linux/delay.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/etherdevice.h>
  29 #include <linux/skbuff.h>
  30 #include <linux/spinlock.h>
  31 #include <linux/mm.h>
  32 #include <linux/module.h>
  33 #include <linux/platform_device.h>
  34 #include <linux/crc32.h>
  35 #include <linux/mii.h>
  36 #include <linux/phy.h>
  37
  38 #include <asm/io.h>
  39 #include <asm/irq.h>
  40 #include <asm/uaccess.h>
  41
  42 #include "gianfar.h"
  43 #include "gianfar_mii.h"
  44
  45 /*
  46  * Write value to the PHY at mii_id at register regnum,
  47  * on the bus attached to the local interface, which may be different from the
  48  * generic mdio bus (tied to a single interface), waiting until the write is
  49  * done before returning. This is helpful in programming interfaces like
  50  * the TBI which control interfaces like onchip SERDES and are always tied to
  51  * the local mdio pins, which may not be the same as system mdio bus, used for
  52  * controlling the external PHYs, for example.
  53  */
  54 int gfar_local_mdio_write(struct gfar_mii __iomem *regs, int mii_id,
  55                           int regnum, u16 value)
  56 {
  57         /* Set the PHY address and the register address we want to write */
  58         gfar_write(&regs->miimadd, (mii_id << 8) | regnum);
  59
  60         /* Write out the value we want */
  61         gfar_write(&regs->miimcon, value);
  62
  63         /* Wait for the transaction to finish */
  64         while (gfar_read(&regs->miimind) & MIIMIND_BUSY)
  65                 cpu_relax();
  66
  67         return 0;
  68 }
  69
  70 /*
  71  * Read the bus for PHY at addr mii_id, register regnum, and
  72  * return the value.  Clears miimcom first.  All PHY operation
  73  * done on the bus attached to the local interface,
  74  * which may be different from the generic mdio bus
  75  * This is helpful in programming interfaces like
  76  * the TBI which, inturn, control interfaces like onchip SERDES
  77  * and are always tied to the local mdio pins, which may not be the
  78  * same as system mdio bus, used for controlling the external PHYs, for eg.
  79  */
  80 int gfar_local_mdio_read(struct gfar_mii __iomem *regs, int mii_id, int regnum)
  81 {
  82         u16 value;
  83
  84         /* Set the PHY address and the register address we want to read */
  85         gfar_write(&regs->miimadd, (mii_id << 8) | regnum);
  86
  87         /* Clear miimcom, and then initiate a read */
  88         gfar_write(&regs->miimcom, 0);
  89         gfar_write(&regs->miimcom, MII_READ_COMMAND);
  90
  91         /* Wait for the transaction to finish */
  92         while (gfar_read(&regs->miimind) & (MIIMIND_NOTVALID | MIIMIND_BUSY))
  93                 cpu_relax();
  94
  95         /* Grab the value of the register from miimstat */
  96         value = gfar_read(&regs->miimstat);
  97
  98         return value;
  99 }
 100
 101 /* Write value to the PHY at mii_id at register regnum,
 102  * on the bus, waiting until the write is done before returning.
 103  * All PHY configuration is done through the TSEC1 MIIM regs */
 104 int gfar_mdio_write(struct mii_bus *bus, int mii_id, int regnum, u16 value)
 105 {
 106         struct gfar_mii __iomem *regs = (void __iomem *)bus->priv;
 107
 108         /* Write to the local MII regs */
 109         return(gfar_local_mdio_write(regs, mii_id, regnum, value));
 110 }
 111
 112 /* Read the bus for PHY at addr mii_id, register regnum, and
 113  * return the value.  Clears miimcom first.  All PHY
 114  * configuration has to be done through the TSEC1 MIIM regs */
 115 int gfar_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
 116 {
 117         struct gfar_mii __iomem *regs = (void __iomem *)bus->priv;
 118
 119         /* Read the local MII regs */
 120         return(gfar_local_mdio_read(regs, mii_id, regnum));
 121 }
 122
 123 /* Reset the MIIM registers, and wait for the bus to free */
 124 static int gfar_mdio_reset(struct mii_bus *bus)
 125 {
 126         struct gfar_mii __iomem *regs = (void __iomem *)bus->priv;
 127         unsigned int timeout = PHY_INIT_TIMEOUT;
 128
 129         mutex_lock(&bus->mdio_lock);
 130
 131         /* Reset the management interface */
 132         gfar_write(&regs->miimcfg, MIIMCFG_RESET);
 133
 134         /* Setup the MII Mgmt clock speed */
 135         gfar_write(&regs->miimcfg, MIIMCFG_INIT_VALUE);
 136
 137         /* Wait until the bus is free */
 138         while ((gfar_read(&regs->miimind) & MIIMIND_BUSY) &&
 139                         --timeout)
 140                 cpu_relax();
 141
 142         mutex_unlock(&bus->mdio_lock);
 143
 144         if(timeout == 0) {
 145                 printk(KERN_ERR "%s: The MII Bus is stuck!\n",
 146                                 bus->name);
 147                 return -EBUSY;
 148         }
 149
 150         return 0;
 151 }
 152
 153
 154 static int gfar_mdio_probe(struct device *dev)
 155 {
 156         struct platform_device *pdev = to_platform_device(dev);
 157         struct gianfar_mdio_data *pdata;
 158         struct gfar_mii __iomem *regs;
 159         struct gfar __iomem *enet_regs;
 160         struct mii_bus *new_bus;
 161         struct resource *r;
 162         int i, err = 0;
 163
 164         if (NULL == dev)
 165                 return -EINVAL;
 166
 167         new_bus = mdiobus_alloc();
 168         if (NULL == new_bus)
 169                 return -ENOMEM;
 170
 171         new_bus->name = "Gianfar MII Bus",
 172         new_bus->read = &gfar_mdio_read,
 173         new_bus->write = &gfar_mdio_write,
 174         new_bus->reset = &gfar_mdio_reset,
 175         snprintf(new_bus->id, MII_BUS_ID_SIZE, "%x", pdev->id);
 176
 177         pdata = (struct gianfar_mdio_data *)pdev->dev.platform_data;
 178
 179         if (NULL == pdata) {
 180                 printk(KERN_ERR "gfar mdio %d: Missing platform data!\n", pdev->id);
 181                 return -ENODEV;
 182         }
 183
 184         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 185
 186         /* Set the PHY base address */
 187         regs = ioremap(r->start, sizeof (struct gfar_mii));
 188
 189         if (NULL == regs) {
 190                 err = -ENOMEM;
 191                 goto reg_map_fail;
 192         }
 193
 194         new_bus->priv = (void __force *)regs;
 195
 196         new_bus->irq = pdata->irq;
 197
 198         new_bus->parent = dev;
 199         dev_set_drvdata(dev, new_bus);
 200
 201         /*
 202          * This is mildly evil, but so is our hardware for doing this.
 203          * Also, we have to cast back to struct gfar_mii because of
 204          * definition weirdness done in gianfar.h.
 205          */
 206         enet_regs = (struct gfar __iomem *)
 207                 ((char *)regs - offsetof(struct gfar, gfar_mii_regs));
 208
 209         /* Scan the bus, looking for an empty spot for TBIPA */
 210         gfar_write(&enet_regs->tbipa, 0);
 211         for (i = PHY_MAX_ADDR; i > 0; i--) {
 212                 u32 phy_id;
 213
 214                 err = get_phy_id(new_bus, i, &phy_id);
 215                 if (err)
 216                         goto bus_register_fail;
 217
 218                 if (phy_id == 0xffffffff)
 219                         break;
 220         }
 221
 222         /* The bus is full.  We don't support using 31 PHYs, sorry */
 223         if (i == 0) {
 224                 err = -EBUSY;
 225
 226                 goto bus_register_fail;
 227         }
 228
 229         gfar_write(&enet_regs->tbipa, i);
 230
 231         err = mdiobus_register(new_bus);
 232
 233         if (0 != err) {
 234                 printk (KERN_ERR "%s: Cannot register as MDIO bus\n",
 235                                 new_bus->name);
 236                 goto bus_register_fail;
 237         }
 238
 239         return 0;
 240
 241 bus_register_fail:
 242         iounmap(regs);
 243 reg_map_fail:
 244         mdiobus_free(new_bus);
 245
 246         return err;
 247 }
 248
 249
 250 static int gfar_mdio_remove(struct device *dev)
 251 {
 252         struct mii_bus *bus = dev_get_drvdata(dev);
 253
 254         mdiobus_unregister(bus);
 255
 256         dev_set_drvdata(dev, NULL);
 257
 258         iounmap((void __iomem *)bus->priv);
 259         bus->priv = NULL;
 260         mdiobus_free(bus);
 261
 262         return 0;
 263 }
 264
 265 static struct device_driver gianfar_mdio_driver = {
 266         .name = "fsl-gianfar_mdio",
 267         .bus = &platform_bus_type,
 268         .probe = gfar_mdio_probe,
 269         .remove = gfar_mdio_remove,
 270 };
 271
 272 static int match_mdio_bus(struct device *dev, void *data)
 273 {
 274         const struct gfar_private *priv = data;
 275         const struct platform_device *pdev = to_platform_device(dev);
 276
 277         return !strcmp(pdev->name, gianfar_mdio_driver.name) &&
 278                 pdev->id == priv->einfo->mdio_bus;
 279 }
 280
 281 /* Given a gfar_priv structure, find the mii_bus controlled by this device (not
 282  * necessarily the same as the bus the gfar's PHY is on), if one exists.
 283  * Normally only the first gianfar controls a mii_bus.  */
 284 struct mii_bus *gfar_get_miibus(const struct gfar_private *priv)
 285 {
 286         /*const*/ struct device *d;
 287
 288         d = bus_find_device(gianfar_mdio_driver.bus, NULL, (void *)priv,
 289                             match_mdio_bus);
 290         return d ? dev_get_drvdata(d) : NULL;
 291 }
 292
 293 int __init gfar_mdio_init(void)
 294 {
 295         return driver_register(&gianfar_mdio_driver);
 296 }
 297
 298 void gfar_mdio_exit(void)
 299 {
 300         driver_unregister(&gianfar_mdio_driver);
 301 }