drivers/net/phy/fixed.c

   1 /*
   2  * Fixed MDIO bus (MDIO bus emulation with fixed PHYs)
   3  *
   4  * Author: Vitaly Bordug <vbordug@ru.mvista.com>
   5  *         Anton Vorontsov <avorontsov@ru.mvista.com>
   6  *
   7  * Copyright (c) 2006-2007 MontaVista Software, Inc.
   8  *
   9  * This program is free software; you can redistribute  it and/or modify it
  10  * under  the terms of  the GNU General  Public License as published by the
  11  * Free Software Foundation;  either version 2 of the  License, or (at your
  12  * option) any later version.
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/list.h>
  19 #include <linux/mii.h>
  20 #include <linux/phy.h>
  21 #include <linux/phy_fixed.h>
  22 #include <linux/err.h>
  23 #include <linux/slab.h>
  24 #include <linux/of.h>
  25
  26 #define MII_REGS_NUM 29
  27
  28 struct fixed_mdio_bus {
  29         int irqs[PHY_MAX_ADDR];
  30         struct mii_bus *mii_bus;
  31         struct list_head phys;
  32 };
  33
  34 struct fixed_phy {
  35         int addr;
  36         u16 regs[MII_REGS_NUM];
  37         struct phy_device *phydev;
  38         struct fixed_phy_status status;
  39         int (*link_update)(struct net_device *, struct fixed_phy_status *);
  40         struct list_head node;
  41 };
  42
  43 static struct platform_device *pdev;
  44 static struct fixed_mdio_bus platform_fmb = {
  45         .phys = LIST_HEAD_INIT(platform_fmb.phys),
  46 };
  47
  48 static int fixed_phy_update_regs(struct fixed_phy *fp)
  49 {
  50         u16 bmsr = BMSR_ANEGCAPABLE;
  51         u16 bmcr = 0;
  52         u16 lpagb = 0;
  53         u16 lpa = 0;
  54
  55         if (fp->status.duplex) {
  56                 bmcr |= BMCR_FULLDPLX;
  57
  58                 switch (fp->status.speed) {
  59                 case 1000:
  60                         bmsr |= BMSR_ESTATEN;
  61                         bmcr |= BMCR_SPEED1000;
  62                         lpagb |= LPA_1000FULL;
  63                         break;
  64                 case 100:
  65                         bmsr |= BMSR_100FULL;
  66                         bmcr |= BMCR_SPEED100;
  67                         lpa |= LPA_100FULL;
  68                         break;
  69                 case 10:
  70                         bmsr |= BMSR_10FULL;
  71                         lpa |= LPA_10FULL;
  72                         break;
  73                 default:
  74                         pr_warn("fixed phy: unknown speed\n");
  75                         return -EINVAL;
  76                 }
  77         } else {
  78                 switch (fp->status.speed) {
  79                 case 1000:
  80                         bmsr |= BMSR_ESTATEN;
  81                         bmcr |= BMCR_SPEED1000;
  82                         lpagb |= LPA_1000HALF;
  83                         break;
  84                 case 100:
  85                         bmsr |= BMSR_100HALF;
  86                         bmcr |= BMCR_SPEED100;
  87                         lpa |= LPA_100HALF;
  88                         break;
  89                 case 10:
  90                         bmsr |= BMSR_10HALF;
  91                         lpa |= LPA_10HALF;
  92                         break;
  93                 default:
  94                         pr_warn("fixed phy: unknown speed\n");
  95                         return -EINVAL;
  96                 }
  97         }
  98
  99         if (fp->status.link)
 100                 bmsr |= BMSR_LSTATUS | BMSR_ANEGCOMPLETE;
 101
 102         if (fp->status.pause)
 103                 lpa |= LPA_PAUSE_CAP;
 104
 105         if (fp->status.asym_pause)
 106                 lpa |= LPA_PAUSE_ASYM;
 107
 108         fp->regs[MII_PHYSID1] = 0;
 109         fp->regs[MII_PHYSID2] = 0;
 110
 111         fp->regs[MII_BMSR] = bmsr;
 112         fp->regs[MII_BMCR] = bmcr;
 113         fp->regs[MII_LPA] = lpa;
 114         fp->regs[MII_STAT1000] = lpagb;
 115
 116         return 0;
 117 }
 118
 119 static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
 120 {
 121         struct fixed_mdio_bus *fmb = bus->priv;
 122         struct fixed_phy *fp;
 123
 124         if (reg_num >= MII_REGS_NUM)
 125                 return -1;
 126
 127         /* We do not support emulating Clause 45 over Clause 22 register reads
 128          * return an error instead of bogus data.
 129          */
 130         switch (reg_num) {
 131         case MII_MMD_CTRL:
 132         case MII_MMD_DATA:
 133                 return -1;
 134         default:
 135                 break;
 136         }
 137
 138         list_for_each_entry(fp, &fmb->phys, node) {
 139                 if (fp->addr == phy_addr) {
 140                         /* Issue callback if user registered it. */
 141                         if (fp->link_update) {
 142                                 fp->link_update(fp->phydev->attached_dev,
 143                                                 &fp->status);
 144                                 fixed_phy_update_regs(fp);
 145                         }
 146                         return fp->regs[reg_num];
 147                 }
 148         }
 149
 150         return 0xFFFF;
 151 }
 152
 153 static int fixed_mdio_write(struct mii_bus *bus, int phy_addr, int reg_num,
 154                             u16 val)
 155 {
 156         return 0;
 157 }
 158
 159 /*
 160  * If something weird is required to be done with link/speed,
 161  * network driver is able to assign a function to implement this.
 162  * May be useful for PHY's that need to be software-driven.
 163  */
 164 int fixed_phy_set_link_update(struct phy_device *phydev,
 165                               int (*link_update)(struct net_device *,
 166                                                  struct fixed_phy_status *))
 167 {
 168         struct fixed_mdio_bus *fmb = &platform_fmb;
 169         struct fixed_phy *fp;
 170
 171         if (!link_update || !phydev || !phydev->bus)
 172                 return -EINVAL;
 173
 174         list_for_each_entry(fp, &fmb->phys, node) {
 175                 if (fp->addr == phydev->addr) {
 176                         fp->link_update = link_update;
 177                         fp->phydev = phydev;
 178                         return 0;
 179                 }
 180         }
 181
 182         return -ENOENT;
 183 }
 184 EXPORT_SYMBOL_GPL(fixed_phy_set_link_update);
 185
 186 int fixed_phy_add(unsigned int irq, int phy_addr,
 187                   struct fixed_phy_status *status)
 188 {
 189         int ret;
 190         struct fixed_mdio_bus *fmb = &platform_fmb;
 191         struct fixed_phy *fp;
 192
 193         fp = kzalloc(sizeof(*fp), GFP_KERNEL);
 194         if (!fp)
 195                 return -ENOMEM;
 196
 197         memset(fp->regs, 0xFF,  sizeof(fp->regs[0]) * MII_REGS_NUM);
 198
 199         fmb->irqs[phy_addr] = irq;
 200
 201         fp->addr = phy_addr;
 202         fp->status = *status;
 203
 204         ret = fixed_phy_update_regs(fp);
 205         if (ret)
 206                 goto err_regs;
 207
 208         list_add_tail(&fp->node, &fmb->phys);
 209
 210         return 0;
 211
 212 err_regs:
 213         kfree(fp);
 214         return ret;
 215 }
 216 EXPORT_SYMBOL_GPL(fixed_phy_add);
 217
 218 void fixed_phy_del(int phy_addr)
 219 {
 220         struct fixed_mdio_bus *fmb = &platform_fmb;
 221         struct fixed_phy *fp, *tmp;
 222
 223         list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
 224                 if (fp->addr == phy_addr) {
 225                         list_del(&fp->node);
 226                         kfree(fp);
 227                         return;
 228                 }
 229         }
 230 }
 231 EXPORT_SYMBOL_GPL(fixed_phy_del);
 232
 233 static int phy_fixed_addr;
 234 static DEFINE_SPINLOCK(phy_fixed_addr_lock);
 235
 236 struct phy_device *fixed_phy_register(unsigned int irq,
 237                                       struct fixed_phy_status *status,
 238                                       struct device_node *np)
 239 {
 240         struct fixed_mdio_bus *fmb = &platform_fmb;
 241         struct phy_device *phy;
 242         int phy_addr;
 243         int ret;
 244
 245         /* Get the next available PHY address, up to PHY_MAX_ADDR */
 246         spin_lock(&phy_fixed_addr_lock);
 247         if (phy_fixed_addr == PHY_MAX_ADDR) {
 248                 spin_unlock(&phy_fixed_addr_lock);
 249                 return ERR_PTR(-ENOSPC);
 250         }
 251         phy_addr = phy_fixed_addr++;
 252         spin_unlock(&phy_fixed_addr_lock);
 253
 254         ret = fixed_phy_add(PHY_POLL, phy_addr, status);
 255         if (ret < 0)
 256                 return ERR_PTR(ret);
 257
 258         phy = get_phy_device(fmb->mii_bus, phy_addr, false);
 259         if (!phy || IS_ERR(phy)) {
 260                 fixed_phy_del(phy_addr);
 261                 return ERR_PTR(-EINVAL);
 262         }
 263
 264         of_node_get(np);
 265         phy->dev.of_node = np;
 266
 267         ret = phy_device_register(phy);
 268         if (ret) {
 269                 phy_device_free(phy);
 270                 of_node_put(np);
 271                 fixed_phy_del(phy_addr);
 272                 return ERR_PTR(ret);
 273         }
 274
 275         return phy;
 276 }
 277
 278 static int __init fixed_mdio_bus_init(void)
 279 {
 280         struct fixed_mdio_bus *fmb = &platform_fmb;
 281         int ret;
 282
 283         pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0);
 284         if (IS_ERR(pdev)) {
 285                 ret = PTR_ERR(pdev);
 286                 goto err_pdev;
 287         }
 288
 289         fmb->mii_bus = mdiobus_alloc();
 290         if (fmb->mii_bus == NULL) {
 291                 ret = -ENOMEM;
 292                 goto err_mdiobus_reg;
 293         }
 294
 295         snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0");
 296         fmb->mii_bus->name = "Fixed MDIO Bus";
 297         fmb->mii_bus->priv = fmb;
 298         fmb->mii_bus->parent = &pdev->dev;
 299         fmb->mii_bus->read = &fixed_mdio_read;
 300         fmb->mii_bus->write = &fixed_mdio_write;
 301         fmb->mii_bus->irq = fmb->irqs;
 302
 303         ret = mdiobus_register(fmb->mii_bus);
 304         if (ret)
 305                 goto err_mdiobus_alloc;
 306
 307         return 0;
 308
 309 err_mdiobus_alloc:
 310         mdiobus_free(fmb->mii_bus);
 311 err_mdiobus_reg:
 312         platform_device_unregister(pdev);
 313 err_pdev:
 314         return ret;
 315 }
 316 module_init(fixed_mdio_bus_init);
 317
 318 static void __exit fixed_mdio_bus_exit(void)
 319 {
 320         struct fixed_mdio_bus *fmb = &platform_fmb;
 321         struct fixed_phy *fp, *tmp;
 322
 323         mdiobus_unregister(fmb->mii_bus);
 324         mdiobus_free(fmb->mii_bus);
 325         platform_device_unregister(pdev);
 326
 327         list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
 328                 list_del(&fp->node);
 329                 kfree(fp);
 330         }
 331 }
 332 module_exit(fixed_mdio_bus_exit);
 333
 334 MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
 335 MODULE_AUTHOR("Vitaly Bordug");
 336 MODULE_LICENSE("GPL");