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 #include <linux/gpio.h>
  26
  27 #define MII_REGS_NUM 29
  28
  29 struct fixed_mdio_bus {
  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         int link_gpio;
  42 };
  43
  44 static struct platform_device *pdev;
  45 static struct fixed_mdio_bus platform_fmb = {
  46         .phys = LIST_HEAD_INIT(platform_fmb.phys),
  47 };
  48
  49 static int fixed_phy_update_regs(struct fixed_phy *fp)
  50 {
  51         u16 bmsr = BMSR_ANEGCAPABLE;
  52         u16 bmcr = 0;
  53         u16 lpagb = 0;
  54         u16 lpa = 0;
  55
  56         if (gpio_is_valid(fp->link_gpio))
  57                 fp->status.link = !!gpio_get_value_cansleep(fp->link_gpio);
  58
  59         if (fp->status.duplex) {
  60                 switch (fp->status.speed) {
  61                 case 1000:
  62                         bmsr |= BMSR_ESTATEN;
  63                         break;
  64                 case 100:
  65                         bmsr |= BMSR_100FULL;
  66                         break;
  67                 case 10:
  68                         bmsr |= BMSR_10FULL;
  69                         break;
  70                 default:
  71                         break;
  72                 }
  73         } else {
  74                 switch (fp->status.speed) {
  75                 case 1000:
  76                         bmsr |= BMSR_ESTATEN;
  77                         break;
  78                 case 100:
  79                         bmsr |= BMSR_100HALF;
  80                         break;
  81                 case 10:
  82                         bmsr |= BMSR_10HALF;
  83                         break;
  84                 default:
  85                         break;
  86                 }
  87         }
  88
  89         if (fp->status.link) {
  90                 bmsr |= BMSR_LSTATUS | BMSR_ANEGCOMPLETE;
  91
  92                 if (fp->status.duplex) {
  93                         bmcr |= BMCR_FULLDPLX;
  94
  95                         switch (fp->status.speed) {
  96                         case 1000:
  97                                 bmcr |= BMCR_SPEED1000;
  98                                 lpagb |= LPA_1000FULL;
  99                                 break;
 100                         case 100:
 101                                 bmcr |= BMCR_SPEED100;
 102                                 lpa |= LPA_100FULL;
 103                                 break;
 104                         case 10:
 105                                 lpa |= LPA_10FULL;
 106                                 break;
 107                         default:
 108                                 pr_warn("fixed phy: unknown speed\n");
 109                                 return -EINVAL;
 110                         }
 111                 } else {
 112                         switch (fp->status.speed) {
 113                         case 1000:
 114                                 bmcr |= BMCR_SPEED1000;
 115                                 lpagb |= LPA_1000HALF;
 116                                 break;
 117                         case 100:
 118                                 bmcr |= BMCR_SPEED100;
 119                                 lpa |= LPA_100HALF;
 120                                 break;
 121                         case 10:
 122                                 lpa |= LPA_10HALF;
 123                                 break;
 124                         default:
 125                                 pr_warn("fixed phy: unknown speed\n");
 126                         return -EINVAL;
 127                         }
 128                 }
 129
 130                 if (fp->status.pause)
 131                         lpa |= LPA_PAUSE_CAP;
 132
 133                 if (fp->status.asym_pause)
 134                         lpa |= LPA_PAUSE_ASYM;
 135         }
 136
 137         fp->regs[MII_PHYSID1] = 0;
 138         fp->regs[MII_PHYSID2] = 0;
 139
 140         fp->regs[MII_BMSR] = bmsr;
 141         fp->regs[MII_BMCR] = bmcr;
 142         fp->regs[MII_LPA] = lpa;
 143         fp->regs[MII_STAT1000] = lpagb;
 144
 145         return 0;
 146 }
 147
 148 static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
 149 {
 150         struct fixed_mdio_bus *fmb = bus->priv;
 151         struct fixed_phy *fp;
 152
 153         if (reg_num >= MII_REGS_NUM)
 154                 return -1;
 155
 156         /* We do not support emulating Clause 45 over Clause 22 register reads
 157          * return an error instead of bogus data.
 158          */
 159         switch (reg_num) {
 160         case MII_MMD_CTRL:
 161         case MII_MMD_DATA:
 162                 return -1;
 163         default:
 164                 break;
 165         }
 166
 167         list_for_each_entry(fp, &fmb->phys, node) {
 168                 if (fp->addr == phy_addr) {
 169                         /* Issue callback if user registered it. */
 170                         if (fp->link_update) {
 171                                 fp->link_update(fp->phydev->attached_dev,
 172                                                 &fp->status);
 173                                 fixed_phy_update_regs(fp);
 174                         }
 175                         return fp->regs[reg_num];
 176                 }
 177         }
 178
 179         return 0xFFFF;
 180 }
 181
 182 static int fixed_mdio_write(struct mii_bus *bus, int phy_addr, int reg_num,
 183                             u16 val)
 184 {
 185         return 0;
 186 }
 187
 188 /*
 189  * If something weird is required to be done with link/speed,
 190  * network driver is able to assign a function to implement this.
 191  * May be useful for PHY's that need to be software-driven.
 192  */
 193 int fixed_phy_set_link_update(struct phy_device *phydev,
 194                               int (*link_update)(struct net_device *,
 195                                                  struct fixed_phy_status *))
 196 {
 197         struct fixed_mdio_bus *fmb = &platform_fmb;
 198         struct fixed_phy *fp;
 199
 200         if (!phydev || !phydev->mdio.bus)
 201                 return -EINVAL;
 202
 203         list_for_each_entry(fp, &fmb->phys, node) {
 204                 if (fp->addr == phydev->mdio.addr) {
 205                         fp->link_update = link_update;
 206                         fp->phydev = phydev;
 207                         return 0;
 208                 }
 209         }
 210
 211         return -ENOENT;
 212 }
 213 EXPORT_SYMBOL_GPL(fixed_phy_set_link_update);
 214
 215 int fixed_phy_update_state(struct phy_device *phydev,
 216                            const struct fixed_phy_status *status,
 217                            const struct fixed_phy_status *changed)
 218 {
 219         struct fixed_mdio_bus *fmb = &platform_fmb;
 220         struct fixed_phy *fp;
 221
 222         if (!phydev || phydev->mdio.bus != fmb->mii_bus)
 223                 return -EINVAL;
 224
 225         list_for_each_entry(fp, &fmb->phys, node) {
 226                 if (fp->addr == phydev->mdio.addr) {
 227 #define _UPD(x) if (changed->x) \
 228         fp->status.x = status->x
 229                         _UPD(link);
 230                         _UPD(speed);
 231                         _UPD(duplex);
 232                         _UPD(pause);
 233                         _UPD(asym_pause);
 234 #undef _UPD
 235                         fixed_phy_update_regs(fp);
 236                         return 0;
 237                 }
 238         }
 239
 240         return -ENOENT;
 241 }
 242 EXPORT_SYMBOL(fixed_phy_update_state);
 243
 244 int fixed_phy_add(unsigned int irq, int phy_addr,
 245                   struct fixed_phy_status *status,
 246                   int link_gpio)
 247 {
 248         int ret;
 249         struct fixed_mdio_bus *fmb = &platform_fmb;
 250         struct fixed_phy *fp;
 251
 252         fp = kzalloc(sizeof(*fp), GFP_KERNEL);
 253         if (!fp)
 254                 return -ENOMEM;
 255
 256         memset(fp->regs, 0xFF,  sizeof(fp->regs[0]) * MII_REGS_NUM);
 257
 258         fmb->mii_bus->irq[phy_addr] = irq;
 259
 260         fp->addr = phy_addr;
 261         fp->status = *status;
 262         fp->link_gpio = link_gpio;
 263
 264         if (gpio_is_valid(fp->link_gpio)) {
 265                 ret = gpio_request_one(fp->link_gpio, GPIOF_DIR_IN,
 266                                        "fixed-link-gpio-link");
 267                 if (ret)
 268                         goto err_regs;
 269         }
 270
 271         ret = fixed_phy_update_regs(fp);
 272         if (ret)
 273                 goto err_gpio;
 274
 275         list_add_tail(&fp->node, &fmb->phys);
 276
 277         return 0;
 278
 279 err_gpio:
 280         if (gpio_is_valid(fp->link_gpio))
 281                 gpio_free(fp->link_gpio);
 282 err_regs:
 283         kfree(fp);
 284         return ret;
 285 }
 286 EXPORT_SYMBOL_GPL(fixed_phy_add);
 287
 288 static void fixed_phy_del(int phy_addr)
 289 {
 290         struct fixed_mdio_bus *fmb = &platform_fmb;
 291         struct fixed_phy *fp, *tmp;
 292
 293         list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
 294                 if (fp->addr == phy_addr) {
 295                         list_del(&fp->node);
 296                         if (gpio_is_valid(fp->link_gpio))
 297                                 gpio_free(fp->link_gpio);
 298                         kfree(fp);
 299                         return;
 300                 }
 301         }
 302 }
 303
 304 static int phy_fixed_addr;
 305 static DEFINE_SPINLOCK(phy_fixed_addr_lock);
 306
 307 struct phy_device *fixed_phy_register(unsigned int irq,
 308                                       struct fixed_phy_status *status,
 309                                       int link_gpio,
 310                                       struct device_node *np)
 311 {
 312         struct fixed_mdio_bus *fmb = &platform_fmb;
 313         struct phy_device *phy;
 314         int phy_addr;
 315         int ret;
 316
 317         /* Get the next available PHY address, up to PHY_MAX_ADDR */
 318         spin_lock(&phy_fixed_addr_lock);
 319         if (phy_fixed_addr == PHY_MAX_ADDR) {
 320                 spin_unlock(&phy_fixed_addr_lock);
 321                 return ERR_PTR(-ENOSPC);
 322         }
 323         phy_addr = phy_fixed_addr++;
 324         spin_unlock(&phy_fixed_addr_lock);
 325
 326         ret = fixed_phy_add(irq, phy_addr, status, link_gpio);
 327         if (ret < 0)
 328                 return ERR_PTR(ret);
 329
 330         phy = get_phy_device(fmb->mii_bus, phy_addr, false);
 331         if (!phy || IS_ERR(phy)) {
 332                 fixed_phy_del(phy_addr);
 333                 return ERR_PTR(-EINVAL);
 334         }
 335
 336         /* propagate the fixed link values to struct phy_device */
 337         phy->link = status->link;
 338         if (status->link) {
 339                 phy->speed = status->speed;
 340                 phy->duplex = status->duplex;
 341                 phy->pause = status->pause;
 342                 phy->asym_pause = status->asym_pause;
 343         }
 344
 345         of_node_get(np);
 346         phy->mdio.dev.of_node = np;
 347         phy->is_pseudo_fixed_link = true;
 348
 349         switch (status->speed) {
 350         case SPEED_1000:
 351                 phy->supported = PHY_1000BT_FEATURES;
 352                 break;
 353         case SPEED_100:
 354                 phy->supported = PHY_100BT_FEATURES;
 355                 break;
 356         case SPEED_10:
 357         default:
 358                 phy->supported = PHY_10BT_FEATURES;
 359         }
 360
 361         ret = phy_device_register(phy);
 362         if (ret) {
 363                 phy_device_free(phy);
 364                 of_node_put(np);
 365                 fixed_phy_del(phy_addr);
 366                 return ERR_PTR(ret);
 367         }
 368
 369         return phy;
 370 }
 371 EXPORT_SYMBOL_GPL(fixed_phy_register);
 372
 373 void fixed_phy_unregister(struct phy_device *phy)
 374 {
 375         phy_device_remove(phy);
 376
 377         fixed_phy_del(phy->mdio.addr);
 378 }
 379 EXPORT_SYMBOL_GPL(fixed_phy_unregister);
 380
 381 static int __init fixed_mdio_bus_init(void)
 382 {
 383         struct fixed_mdio_bus *fmb = &platform_fmb;
 384         int ret;
 385
 386         pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0);
 387         if (IS_ERR(pdev)) {
 388                 ret = PTR_ERR(pdev);
 389                 goto err_pdev;
 390         }
 391
 392         fmb->mii_bus = mdiobus_alloc();
 393         if (fmb->mii_bus == NULL) {
 394                 ret = -ENOMEM;
 395                 goto err_mdiobus_reg;
 396         }
 397
 398         snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0");
 399         fmb->mii_bus->name = "Fixed MDIO Bus";
 400         fmb->mii_bus->priv = fmb;
 401         fmb->mii_bus->parent = &pdev->dev;
 402         fmb->mii_bus->read = &fixed_mdio_read;
 403         fmb->mii_bus->write = &fixed_mdio_write;
 404
 405         ret = mdiobus_register(fmb->mii_bus);
 406         if (ret)
 407                 goto err_mdiobus_alloc;
 408
 409         return 0;
 410
 411 err_mdiobus_alloc:
 412         mdiobus_free(fmb->mii_bus);
 413 err_mdiobus_reg:
 414         platform_device_unregister(pdev);
 415 err_pdev:
 416         return ret;
 417 }
 418 module_init(fixed_mdio_bus_init);
 419
 420 static void __exit fixed_mdio_bus_exit(void)
 421 {
 422         struct fixed_mdio_bus *fmb = &platform_fmb;
 423         struct fixed_phy *fp, *tmp;
 424
 425         mdiobus_unregister(fmb->mii_bus);
 426         mdiobus_free(fmb->mii_bus);
 427         platform_device_unregister(pdev);
 428
 429         list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
 430                 list_del(&fp->node);
 431                 kfree(fp);
 432         }
 433 }
 434 module_exit(fixed_mdio_bus_exit);
 435
 436 MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
 437 MODULE_AUTHOR("Vitaly Bordug");
 438 MODULE_LICENSE("GPL");