drivers/net/phy/fixed_phy.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.link)
  56                 goto done;
  57         bmsr |= BMSR_LSTATUS | BMSR_ANEGCOMPLETE;
  58
  59         if (fp->status.duplex) {
  60                 bmcr |= BMCR_FULLDPLX;
  61
  62                 switch (fp->status.speed) {
  63                 case 1000:
  64                         bmsr |= BMSR_ESTATEN;
  65                         bmcr |= BMCR_SPEED1000;
  66                         lpagb |= LPA_1000FULL;
  67                         break;
  68                 case 100:
  69                         bmsr |= BMSR_100FULL;
  70                         bmcr |= BMCR_SPEED100;
  71                         lpa |= LPA_100FULL;
  72                         break;
  73                 case 10:
  74                         bmsr |= BMSR_10FULL;
  75                         lpa |= LPA_10FULL;
  76                         break;
  77                 default:
  78                         pr_warn("fixed phy: unknown speed\n");
  79                         return -EINVAL;
  80                 }
  81         } else {
  82                 switch (fp->status.speed) {
  83                 case 1000:
  84                         bmsr |= BMSR_ESTATEN;
  85                         bmcr |= BMCR_SPEED1000;
  86                         lpagb |= LPA_1000HALF;
  87                         break;
  88                 case 100:
  89                         bmsr |= BMSR_100HALF;
  90                         bmcr |= BMCR_SPEED100;
  91                         lpa |= LPA_100HALF;
  92                         break;
  93                 case 10:
  94                         bmsr |= BMSR_10HALF;
  95                         lpa |= LPA_10HALF;
  96                         break;
  97                 default:
  98                         pr_warn("fixed phy: unknown speed\n");
  99                         return -EINVAL;
 100                 }
 101         }
 102
 103         if (fp->status.pause)
 104                 lpa |= LPA_PAUSE_CAP;
 105
 106         if (fp->status.asym_pause)
 107                 lpa |= LPA_PAUSE_ASYM;
 108
 109 done:
 110         fp->regs[MII_PHYSID1] = 0;
 111         fp->regs[MII_PHYSID2] = 0;
 112
 113         fp->regs[MII_BMSR] = bmsr;
 114         fp->regs[MII_BMCR] = bmcr;
 115         fp->regs[MII_LPA] = lpa;
 116         fp->regs[MII_STAT1000] = lpagb;
 117
 118         return 0;
 119 }
 120
 121 static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
 122 {
 123         struct fixed_mdio_bus *fmb = bus->priv;
 124         struct fixed_phy *fp;
 125
 126         if (reg_num >= MII_REGS_NUM)
 127                 return -1;
 128
 129         /* We do not support emulating Clause 45 over Clause 22 register reads
 130          * return an error instead of bogus data.
 131          */
 132         switch (reg_num) {
 133         case MII_MMD_CTRL:
 134         case MII_MMD_DATA:
 135                 return -1;
 136         default:
 137                 break;
 138         }
 139
 140         list_for_each_entry(fp, &fmb->phys, node) {
 141                 if (fp->addr == phy_addr) {
 142                         /* Issue callback if user registered it. */
 143                         if (fp->link_update) {
 144                                 fp->link_update(fp->phydev->attached_dev,
 145                                                 &fp->status);
 146                                 fixed_phy_update_regs(fp);
 147                         }
 148                         return fp->regs[reg_num];
 149                 }
 150         }
 151
 152         return 0xFFFF;
 153 }
 154
 155 static int fixed_mdio_write(struct mii_bus *bus, int phy_addr, int reg_num,
 156                             u16 val)
 157 {
 158         return 0;
 159 }
 160
 161 /*
 162  * If something weird is required to be done with link/speed,
 163  * network driver is able to assign a function to implement this.
 164  * May be useful for PHY's that need to be software-driven.
 165  */
 166 int fixed_phy_set_link_update(struct phy_device *phydev,
 167                               int (*link_update)(struct net_device *,
 168                                                  struct fixed_phy_status *))
 169 {
 170         struct fixed_mdio_bus *fmb = &platform_fmb;
 171         struct fixed_phy *fp;
 172
 173         if (!phydev || !phydev->bus)
 174                 return -EINVAL;
 175
 176         list_for_each_entry(fp, &fmb->phys, node) {
 177                 if (fp->addr == phydev->addr) {
 178                         fp->link_update = link_update;
 179                         fp->phydev = phydev;
 180                         return 0;
 181                 }
 182         }
 183
 184         return -ENOENT;
 185 }
 186 EXPORT_SYMBOL_GPL(fixed_phy_set_link_update);
 187
 188 int fixed_phy_update_state(struct phy_device *phydev,
 189                            const struct fixed_phy_status *status,
 190                            const struct fixed_phy_status *changed)
 191 {
 192         struct fixed_mdio_bus *fmb = &platform_fmb;
 193         struct fixed_phy *fp;
 194
 195         if (!phydev || !phydev->bus)
 196                 return -EINVAL;
 197
 198         list_for_each_entry(fp, &fmb->phys, node) {
 199                 if (fp->addr == phydev->addr) {
 200 #define _UPD(x) if (changed->x) \
 201         fp->status.x = status->x
 202                         _UPD(link);
 203                         _UPD(speed);
 204                         _UPD(duplex);
 205                         _UPD(pause);
 206                         _UPD(asym_pause);
 207 #undef _UPD
 208                         fixed_phy_update_regs(fp);
 209                         return 0;
 210                 }
 211         }
 212
 213         return -ENOENT;
 214 }
 215 EXPORT_SYMBOL(fixed_phy_update_state);
 216
 217 int fixed_phy_add(unsigned int irq, int phy_addr,
 218                   struct fixed_phy_status *status)
 219 {
 220         int ret;
 221         struct fixed_mdio_bus *fmb = &platform_fmb;
 222         struct fixed_phy *fp;
 223
 224         fp = kzalloc(sizeof(*fp), GFP_KERNEL);
 225         if (!fp)
 226                 return -ENOMEM;
 227
 228         memset(fp->regs, 0xFF,  sizeof(fp->regs[0]) * MII_REGS_NUM);
 229
 230         fmb->irqs[phy_addr] = irq;
 231
 232         fp->addr = phy_addr;
 233         fp->status = *status;
 234
 235         ret = fixed_phy_update_regs(fp);
 236         if (ret)
 237                 goto err_regs;
 238
 239         list_add_tail(&fp->node, &fmb->phys);
 240
 241         return 0;
 242
 243 err_regs:
 244         kfree(fp);
 245         return ret;
 246 }
 247 EXPORT_SYMBOL_GPL(fixed_phy_add);
 248
 249 void fixed_phy_del(int phy_addr)
 250 {
 251         struct fixed_mdio_bus *fmb = &platform_fmb;
 252         struct fixed_phy *fp, *tmp;
 253
 254         list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
 255                 if (fp->addr == phy_addr) {
 256                         list_del(&fp->node);
 257                         kfree(fp);
 258                         return;
 259                 }
 260         }
 261 }
 262 EXPORT_SYMBOL_GPL(fixed_phy_del);
 263
 264 static int phy_fixed_addr;
 265 static DEFINE_SPINLOCK(phy_fixed_addr_lock);
 266
 267 struct phy_device *fixed_phy_register(unsigned int irq,
 268                                       struct fixed_phy_status *status,
 269                                       struct device_node *np)
 270 {
 271         struct fixed_mdio_bus *fmb = &platform_fmb;
 272         struct phy_device *phy;
 273         int phy_addr;
 274         int ret;
 275
 276         /* Get the next available PHY address, up to PHY_MAX_ADDR */
 277         spin_lock(&phy_fixed_addr_lock);
 278         if (phy_fixed_addr == PHY_MAX_ADDR) {
 279                 spin_unlock(&phy_fixed_addr_lock);
 280                 return ERR_PTR(-ENOSPC);
 281         }
 282         phy_addr = phy_fixed_addr++;
 283         spin_unlock(&phy_fixed_addr_lock);
 284
 285         ret = fixed_phy_add(PHY_POLL, phy_addr, status);
 286         if (ret < 0)
 287                 return ERR_PTR(ret);
 288
 289         phy = get_phy_device(fmb->mii_bus, phy_addr, false);
 290         if (!phy || IS_ERR(phy)) {
 291                 fixed_phy_del(phy_addr);
 292                 return ERR_PTR(-EINVAL);
 293         }
 294
 295         of_node_get(np);
 296         phy->dev.of_node = np;
 297
 298         ret = phy_device_register(phy);
 299         if (ret) {
 300                 phy_device_free(phy);
 301                 of_node_put(np);
 302                 fixed_phy_del(phy_addr);
 303                 return ERR_PTR(ret);
 304         }
 305
 306         return phy;
 307 }
 308 EXPORT_SYMBOL_GPL(fixed_phy_register);
 309
 310 static int __init fixed_mdio_bus_init(void)
 311 {
 312         struct fixed_mdio_bus *fmb = &platform_fmb;
 313         int ret;
 314
 315         pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0);
 316         if (IS_ERR(pdev)) {
 317                 ret = PTR_ERR(pdev);
 318                 goto err_pdev;
 319         }
 320
 321         fmb->mii_bus = mdiobus_alloc();
 322         if (fmb->mii_bus == NULL) {
 323                 ret = -ENOMEM;
 324                 goto err_mdiobus_reg;
 325         }
 326
 327         snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0");
 328         fmb->mii_bus->name = "Fixed MDIO Bus";
 329         fmb->mii_bus->priv = fmb;
 330         fmb->mii_bus->parent = &pdev->dev;
 331         fmb->mii_bus->read = &fixed_mdio_read;
 332         fmb->mii_bus->write = &fixed_mdio_write;
 333         fmb->mii_bus->irq = fmb->irqs;
 334
 335         ret = mdiobus_register(fmb->mii_bus);
 336         if (ret)
 337                 goto err_mdiobus_alloc;
 338
 339         return 0;
 340
 341 err_mdiobus_alloc:
 342         mdiobus_free(fmb->mii_bus);
 343 err_mdiobus_reg:
 344         platform_device_unregister(pdev);
 345 err_pdev:
 346         return ret;
 347 }
 348 module_init(fixed_mdio_bus_init);
 349
 350 static void __exit fixed_mdio_bus_exit(void)
 351 {
 352         struct fixed_mdio_bus *fmb = &platform_fmb;
 353         struct fixed_phy *fp, *tmp;
 354
 355         mdiobus_unregister(fmb->mii_bus);
 356         mdiobus_free(fmb->mii_bus);
 357         platform_device_unregister(pdev);
 358
 359         list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
 360                 list_del(&fp->node);
 361                 kfree(fp);
 362         }
 363 }
 364 module_exit(fixed_mdio_bus_exit);
 365
 366 MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
 367 MODULE_AUTHOR("Vitaly Bordug");
 368 MODULE_LICENSE("GPL");