linux/drivers/net/phy/fixed_phy.c
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   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
  29struct fixed_mdio_bus {
  30        struct mii_bus *mii_bus;
  31        struct list_head phys;
  32};
  33
  34struct 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
  44static struct platform_device *pdev;
  45static struct fixed_mdio_bus platform_fmb = {
  46        .phys = LIST_HEAD_INIT(platform_fmb.phys),
  47};
  48
  49static 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
 148static 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
 182static 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 */
 193int 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}
 213EXPORT_SYMBOL_GPL(fixed_phy_set_link_update);
 214
 215int 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}
 242EXPORT_SYMBOL(fixed_phy_update_state);
 243
 244int 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
 279err_gpio:
 280        if (gpio_is_valid(fp->link_gpio))
 281                gpio_free(fp->link_gpio);
 282err_regs:
 283        kfree(fp);
 284        return ret;
 285}
 286EXPORT_SYMBOL_GPL(fixed_phy_add);
 287
 288static 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
 304static int phy_fixed_addr;
 305static DEFINE_SPINLOCK(phy_fixed_addr_lock);
 306
 307struct 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}
 371EXPORT_SYMBOL_GPL(fixed_phy_register);
 372
 373void fixed_phy_unregister(struct phy_device *phy)
 374{
 375        phy_device_remove(phy);
 376
 377        fixed_phy_del(phy->mdio.addr);
 378}
 379EXPORT_SYMBOL_GPL(fixed_phy_unregister);
 380
 381static 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
 411err_mdiobus_alloc:
 412        mdiobus_free(fmb->mii_bus);
 413err_mdiobus_reg:
 414        platform_device_unregister(pdev);
 415err_pdev:
 416        return ret;
 417}
 418module_init(fixed_mdio_bus_init);
 419
 420static 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}
 434module_exit(fixed_mdio_bus_exit);
 435
 436MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
 437MODULE_AUTHOR("Vitaly Bordug");
 438MODULE_LICENSE("GPL");
 439