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 #include <linux/idr.h>
  27
  28 #define MII_REGS_NUM 29
  29
  30 struct fixed_mdio_bus {
  31         struct mii_bus *mii_bus;
  32         struct list_head phys;
  33 };
  34
  35 struct fixed_phy {
  36         int addr;
  37         u16 regs[MII_REGS_NUM];
  38         struct phy_device *phydev;
  39         struct fixed_phy_status status;
  40         int (*link_update)(struct net_device *, struct fixed_phy_status *);
  41         struct list_head node;
  42         int link_gpio;
  43 };
  44
  45 static struct platform_device *pdev;
  46 static struct fixed_mdio_bus platform_fmb = {
  47         .phys = LIST_HEAD_INIT(platform_fmb.phys),
  48 };
  49
  50 static int fixed_phy_update_regs(struct fixed_phy *fp)
  51 {
  52         u16 bmsr = BMSR_ANEGCAPABLE;
  53         u16 bmcr = 0;
  54         u16 lpagb = 0;
  55         u16 lpa = 0;
  56
  57         if (gpio_is_valid(fp->link_gpio))
  58                 fp->status.link = !!gpio_get_value_cansleep(fp->link_gpio);
  59
  60         if (fp->status.duplex) {
  61                 switch (fp->status.speed) {
  62                 case 1000:
  63                         bmsr |= BMSR_ESTATEN;
  64                         break;
  65                 case 100:
  66                         bmsr |= BMSR_100FULL;
  67                         break;
  68                 case 10:
  69                         bmsr |= BMSR_10FULL;
  70                         break;
  71                 default:
  72                         break;
  73                 }
  74         } else {
  75                 switch (fp->status.speed) {
  76                 case 1000:
  77                         bmsr |= BMSR_ESTATEN;
  78                         break;
  79                 case 100:
  80                         bmsr |= BMSR_100HALF;
  81                         break;
  82                 case 10:
  83                         bmsr |= BMSR_10HALF;
  84                         break;
  85                 default:
  86                         break;
  87                 }
  88         }
  89
  90         if (fp->status.link) {
  91                 bmsr |= BMSR_LSTATUS | BMSR_ANEGCOMPLETE;
  92
  93                 if (fp->status.duplex) {
  94                         bmcr |= BMCR_FULLDPLX;
  95
  96                         switch (fp->status.speed) {
  97                         case 1000:
  98                                 bmcr |= BMCR_SPEED1000;
  99                                 lpagb |= LPA_1000FULL;
 100                                 break;
 101                         case 100:
 102                                 bmcr |= BMCR_SPEED100;
 103                                 lpa |= LPA_100FULL;
 104                                 break;
 105                         case 10:
 106                                 lpa |= LPA_10FULL;
 107                                 break;
 108                         default:
 109                                 pr_warn("fixed phy: unknown speed\n");
 110                                 return -EINVAL;
 111                         }
 112                 } else {
 113                         switch (fp->status.speed) {
 114                         case 1000:
 115                                 bmcr |= BMCR_SPEED1000;
 116                                 lpagb |= LPA_1000HALF;
 117                                 break;
 118                         case 100:
 119                                 bmcr |= BMCR_SPEED100;
 120                                 lpa |= LPA_100HALF;
 121                                 break;
 122                         case 10:
 123                                 lpa |= LPA_10HALF;
 124                                 break;
 125                         default:
 126                                 pr_warn("fixed phy: unknown speed\n");
 127                         return -EINVAL;
 128                         }
 129                 }
 130
 131                 if (fp->status.pause)
 132                         lpa |= LPA_PAUSE_CAP;
 133
 134                 if (fp->status.asym_pause)
 135                         lpa |= LPA_PAUSE_ASYM;
 136         }
 137
 138         fp->regs[MII_PHYSID1] = 0;
 139         fp->regs[MII_PHYSID2] = 0;
 140
 141         fp->regs[MII_BMSR] = bmsr;
 142         fp->regs[MII_BMCR] = bmcr;
 143         fp->regs[MII_LPA] = lpa;
 144         fp->regs[MII_STAT1000] = lpagb;
 145
 146         return 0;
 147 }
 148
 149 static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
 150 {
 151         struct fixed_mdio_bus *fmb = bus->priv;
 152         struct fixed_phy *fp;
 153
 154         if (reg_num >= MII_REGS_NUM)
 155                 return -1;
 156
 157         /* We do not support emulating Clause 45 over Clause 22 register reads
 158          * return an error instead of bogus data.
 159          */
 160         switch (reg_num) {
 161         case MII_MMD_CTRL:
 162         case MII_MMD_DATA:
 163                 return -1;
 164         default:
 165                 break;
 166         }
 167
 168         list_for_each_entry(fp, &fmb->phys, node) {
 169                 if (fp->addr == phy_addr) {
 170                         /* Issue callback if user registered it. */
 171                         if (fp->link_update) {
 172                                 fp->link_update(fp->phydev->attached_dev,
 173                                                 &fp->status);
 174                                 fixed_phy_update_regs(fp);
 175                         }
 176                         return fp->regs[reg_num];
 177                 }
 178         }
 179
 180         return 0xFFFF;
 181 }
 182
 183 static int fixed_mdio_write(struct mii_bus *bus, int phy_addr, int reg_num,
 184                             u16 val)
 185 {
 186         return 0;
 187 }
 188
 189 /*
 190  * If something weird is required to be done with link/speed,
 191  * network driver is able to assign a function to implement this.
 192  * May be useful for PHY's that need to be software-driven.
 193  */
 194 int fixed_phy_set_link_update(struct phy_device *phydev,
 195                               int (*link_update)(struct net_device *,
 196                                                  struct fixed_phy_status *))
 197 {
 198         struct fixed_mdio_bus *fmb = &platform_fmb;
 199         struct fixed_phy *fp;
 200
 201         if (!phydev || !phydev->mdio.bus)
 202                 return -EINVAL;
 203
 204         list_for_each_entry(fp, &fmb->phys, node) {
 205                 if (fp->addr == phydev->mdio.addr) {
 206                         fp->link_update = link_update;
 207                         fp->phydev = phydev;
 208                         return 0;
 209                 }
 210         }
 211
 212         return -ENOENT;
 213 }
 214 EXPORT_SYMBOL_GPL(fixed_phy_set_link_update);
 215
 216 int fixed_phy_update_state(struct phy_device *phydev,
 217                            const struct fixed_phy_status *status,
 218                            const struct fixed_phy_status *changed)
 219 {
 220         struct fixed_mdio_bus *fmb = &platform_fmb;
 221         struct fixed_phy *fp;
 222
 223         if (!phydev || phydev->mdio.bus != fmb->mii_bus)
 224                 return -EINVAL;
 225
 226         list_for_each_entry(fp, &fmb->phys, node) {
 227                 if (fp->addr == phydev->mdio.addr) {
 228 #define _UPD(x) if (changed->x) \
 229         fp->status.x = status->x
 230                         _UPD(link);
 231                         _UPD(speed);
 232                         _UPD(duplex);
 233                         _UPD(pause);
 234                         _UPD(asym_pause);
 235 #undef _UPD
 236                         fixed_phy_update_regs(fp);
 237                         return 0;
 238                 }
 239         }
 240
 241         return -ENOENT;
 242 }
 243 EXPORT_SYMBOL(fixed_phy_update_state);
 244
 245 int fixed_phy_add(unsigned int irq, int phy_addr,
 246                   struct fixed_phy_status *status,
 247                   int link_gpio)
 248 {
 249         int ret;
 250         struct fixed_mdio_bus *fmb = &platform_fmb;
 251         struct fixed_phy *fp;
 252
 253         fp = kzalloc(sizeof(*fp), GFP_KERNEL);
 254         if (!fp)
 255                 return -ENOMEM;
 256
 257         memset(fp->regs, 0xFF,  sizeof(fp->regs[0]) * MII_REGS_NUM);
 258
 259         if (irq != PHY_POLL)
 260                 fmb->mii_bus->irq[phy_addr] = irq;
 261
 262         fp->addr = phy_addr;
 263         fp->status = *status;
 264         fp->link_gpio = link_gpio;
 265
 266         if (gpio_is_valid(fp->link_gpio)) {
 267                 ret = gpio_request_one(fp->link_gpio, GPIOF_DIR_IN,
 268                                        "fixed-link-gpio-link");
 269                 if (ret)
 270                         goto err_regs;
 271         }
 272
 273         ret = fixed_phy_update_regs(fp);
 274         if (ret)
 275                 goto err_gpio;
 276
 277         list_add_tail(&fp->node, &fmb->phys);
 278
 279         return 0;
 280
 281 err_gpio:
 282         if (gpio_is_valid(fp->link_gpio))
 283                 gpio_free(fp->link_gpio);
 284 err_regs:
 285         kfree(fp);
 286         return ret;
 287 }
 288 EXPORT_SYMBOL_GPL(fixed_phy_add);
 289
 290 static DEFINE_IDA(phy_fixed_ida);
 291
 292 static void fixed_phy_del(int phy_addr)
 293 {
 294         struct fixed_mdio_bus *fmb = &platform_fmb;
 295         struct fixed_phy *fp, *tmp;
 296
 297         list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
 298                 if (fp->addr == phy_addr) {
 299                         list_del(&fp->node);
 300                         if (gpio_is_valid(fp->link_gpio))
 301                                 gpio_free(fp->link_gpio);
 302                         kfree(fp);
 303                         ida_simple_remove(&phy_fixed_ida, phy_addr);
 304                         return;
 305                 }
 306         }
 307 }
 308
 309 struct phy_device *fixed_phy_register(unsigned int irq,
 310                                       struct fixed_phy_status *status,
 311                                       int link_gpio,
 312                                       struct device_node *np)
 313 {
 314         struct fixed_mdio_bus *fmb = &platform_fmb;
 315         struct phy_device *phy;
 316         int phy_addr;
 317         int ret;
 318
 319         if (!fmb->mii_bus || fmb->mii_bus->state != MDIOBUS_REGISTERED)
 320                 return ERR_PTR(-EPROBE_DEFER);
 321
 322         /* Get the next available PHY address, up to PHY_MAX_ADDR */
 323         phy_addr = ida_simple_get(&phy_fixed_ida, 0, PHY_MAX_ADDR, GFP_KERNEL);
 324         if (phy_addr < 0)
 325                 return ERR_PTR(phy_addr);
 326
 327         ret = fixed_phy_add(irq, phy_addr, status, link_gpio);
 328         if (ret < 0) {
 329                 ida_simple_remove(&phy_fixed_ida, phy_addr);
 330                 return ERR_PTR(ret);
 331         }
 332
 333         phy = get_phy_device(fmb->mii_bus, phy_addr, false);
 334         if (IS_ERR(phy)) {
 335                 fixed_phy_del(phy_addr);
 336                 return ERR_PTR(-EINVAL);
 337         }
 338
 339         /* propagate the fixed link values to struct phy_device */
 340         phy->link = status->link;
 341         if (status->link) {
 342                 phy->speed = status->speed;
 343                 phy->duplex = status->duplex;
 344                 phy->pause = status->pause;
 345                 phy->asym_pause = status->asym_pause;
 346         }
 347
 348         of_node_get(np);
 349         phy->mdio.dev.of_node = np;
 350         phy->is_pseudo_fixed_link = true;
 351
 352         switch (status->speed) {
 353         case SPEED_1000:
 354                 phy->supported = PHY_1000BT_FEATURES;
 355                 break;
 356         case SPEED_100:
 357                 phy->supported = PHY_100BT_FEATURES;
 358                 break;
 359         case SPEED_10:
 360         default:
 361                 phy->supported = PHY_10BT_FEATURES;
 362         }
 363
 364         ret = phy_device_register(phy);
 365         if (ret) {
 366                 phy_device_free(phy);
 367                 of_node_put(np);
 368                 fixed_phy_del(phy_addr);
 369                 return ERR_PTR(ret);
 370         }
 371
 372         return phy;
 373 }
 374 EXPORT_SYMBOL_GPL(fixed_phy_register);
 375
 376 void fixed_phy_unregister(struct phy_device *phy)
 377 {
 378         phy_device_remove(phy);
 379
 380         fixed_phy_del(phy->mdio.addr);
 381 }
 382 EXPORT_SYMBOL_GPL(fixed_phy_unregister);
 383
 384 static int __init fixed_mdio_bus_init(void)
 385 {
 386         struct fixed_mdio_bus *fmb = &platform_fmb;
 387         int ret;
 388
 389         pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0);
 390         if (IS_ERR(pdev)) {
 391                 ret = PTR_ERR(pdev);
 392                 goto err_pdev;
 393         }
 394
 395         fmb->mii_bus = mdiobus_alloc();
 396         if (fmb->mii_bus == NULL) {
 397                 ret = -ENOMEM;
 398                 goto err_mdiobus_reg;
 399         }
 400
 401         snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0");
 402         fmb->mii_bus->name = "Fixed MDIO Bus";
 403         fmb->mii_bus->priv = fmb;
 404         fmb->mii_bus->parent = &pdev->dev;
 405         fmb->mii_bus->read = &fixed_mdio_read;
 406         fmb->mii_bus->write = &fixed_mdio_write;
 407
 408         ret = mdiobus_register(fmb->mii_bus);
 409         if (ret)
 410                 goto err_mdiobus_alloc;
 411
 412         return 0;
 413
 414 err_mdiobus_alloc:
 415         mdiobus_free(fmb->mii_bus);
 416 err_mdiobus_reg:
 417         platform_device_unregister(pdev);
 418 err_pdev:
 419         return ret;
 420 }
 421 module_init(fixed_mdio_bus_init);
 422
 423 static void __exit fixed_mdio_bus_exit(void)
 424 {
 425         struct fixed_mdio_bus *fmb = &platform_fmb;
 426         struct fixed_phy *fp, *tmp;
 427
 428         mdiobus_unregister(fmb->mii_bus);
 429         mdiobus_free(fmb->mii_bus);
 430         platform_device_unregister(pdev);
 431
 432         list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
 433                 list_del(&fp->node);
 434                 kfree(fp);
 435         }
 436         ida_destroy(&phy_fixed_ida);
 437 }
 438 module_exit(fixed_mdio_bus_exit);
 439
 440 MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
 441 MODULE_AUTHOR("Vitaly Bordug");
 442 MODULE_LICENSE("GPL");