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 #include "swphy.h"
  28
  29 #define MII_REGS_NUM 29
  30
  31 struct fixed_mdio_bus {
  32         struct mii_bus *mii_bus;
  33         struct list_head phys;
  34 };
  35
  36 struct fixed_phy {
  37         int addr;
  38         u16 regs[MII_REGS_NUM];
  39         struct phy_device *phydev;
  40         struct fixed_phy_status status;
  41         int (*link_update)(struct net_device *, struct fixed_phy_status *);
  42         struct list_head node;
  43         int link_gpio;
  44 };
  45
  46 static struct platform_device *pdev;
  47 static struct fixed_mdio_bus platform_fmb = {
  48         .phys = LIST_HEAD_INIT(platform_fmb.phys),
  49 };
  50
  51 static int fixed_phy_update_regs(struct fixed_phy *fp)
  52 {
  53         if (gpio_is_valid(fp->link_gpio))
  54                 fp->status.link = !!gpio_get_value_cansleep(fp->link_gpio);
  55
  56         return swphy_update_regs(fp->regs, &fp->status);
  57 }
  58
  59 static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
  60 {
  61         struct fixed_mdio_bus *fmb = bus->priv;
  62         struct fixed_phy *fp;
  63
  64         if (reg_num >= MII_REGS_NUM)
  65                 return -1;
  66
  67         /* We do not support emulating Clause 45 over Clause 22 register reads
  68          * return an error instead of bogus data.
  69          */
  70         switch (reg_num) {
  71         case MII_MMD_CTRL:
  72         case MII_MMD_DATA:
  73                 return -1;
  74         default:
  75                 break;
  76         }
  77
  78         list_for_each_entry(fp, &fmb->phys, node) {
  79                 if (fp->addr == phy_addr) {
  80                         /* Issue callback if user registered it. */
  81                         if (fp->link_update) {
  82                                 fp->link_update(fp->phydev->attached_dev,
  83                                                 &fp->status);
  84                                 fixed_phy_update_regs(fp);
  85                         }
  86                         return fp->regs[reg_num];
  87                 }
  88         }
  89
  90         return 0xFFFF;
  91 }
  92
  93 static int fixed_mdio_write(struct mii_bus *bus, int phy_addr, int reg_num,
  94                             u16 val)
  95 {
  96         return 0;
  97 }
  98
  99 /*
 100  * If something weird is required to be done with link/speed,
 101  * network driver is able to assign a function to implement this.
 102  * May be useful for PHY's that need to be software-driven.
 103  */
 104 int fixed_phy_set_link_update(struct phy_device *phydev,
 105                               int (*link_update)(struct net_device *,
 106                                                  struct fixed_phy_status *))
 107 {
 108         struct fixed_mdio_bus *fmb = &platform_fmb;
 109         struct fixed_phy *fp;
 110
 111         if (!phydev || !phydev->mdio.bus)
 112                 return -EINVAL;
 113
 114         list_for_each_entry(fp, &fmb->phys, node) {
 115                 if (fp->addr == phydev->mdio.addr) {
 116                         fp->link_update = link_update;
 117                         fp->phydev = phydev;
 118                         return 0;
 119                 }
 120         }
 121
 122         return -ENOENT;
 123 }
 124 EXPORT_SYMBOL_GPL(fixed_phy_set_link_update);
 125
 126 int fixed_phy_update_state(struct phy_device *phydev,
 127                            const struct fixed_phy_status *status,
 128                            const struct fixed_phy_status *changed)
 129 {
 130         struct fixed_mdio_bus *fmb = &platform_fmb;
 131         struct fixed_phy *fp;
 132
 133         if (!phydev || phydev->mdio.bus != fmb->mii_bus)
 134                 return -EINVAL;
 135
 136         list_for_each_entry(fp, &fmb->phys, node) {
 137                 if (fp->addr == phydev->mdio.addr) {
 138 #define _UPD(x) if (changed->x) \
 139         fp->status.x = status->x
 140                         _UPD(link);
 141                         _UPD(speed);
 142                         _UPD(duplex);
 143                         _UPD(pause);
 144                         _UPD(asym_pause);
 145 #undef _UPD
 146                         fixed_phy_update_regs(fp);
 147                         return 0;
 148                 }
 149         }
 150
 151         return -ENOENT;
 152 }
 153 EXPORT_SYMBOL(fixed_phy_update_state);
 154
 155 int fixed_phy_add(unsigned int irq, int phy_addr,
 156                   struct fixed_phy_status *status,
 157                   int link_gpio)
 158 {
 159         int ret;
 160         struct fixed_mdio_bus *fmb = &platform_fmb;
 161         struct fixed_phy *fp;
 162
 163         fp = kzalloc(sizeof(*fp), GFP_KERNEL);
 164         if (!fp)
 165                 return -ENOMEM;
 166
 167         memset(fp->regs, 0xFF,  sizeof(fp->regs[0]) * MII_REGS_NUM);
 168
 169         if (irq != PHY_POLL)
 170                 fmb->mii_bus->irq[phy_addr] = irq;
 171
 172         fp->addr = phy_addr;
 173         fp->status = *status;
 174         fp->link_gpio = link_gpio;
 175
 176         if (gpio_is_valid(fp->link_gpio)) {
 177                 ret = gpio_request_one(fp->link_gpio, GPIOF_DIR_IN,
 178                                        "fixed-link-gpio-link");
 179                 if (ret)
 180                         goto err_regs;
 181         }
 182
 183         ret = fixed_phy_update_regs(fp);
 184         if (ret)
 185                 goto err_gpio;
 186
 187         list_add_tail(&fp->node, &fmb->phys);
 188
 189         return 0;
 190
 191 err_gpio:
 192         if (gpio_is_valid(fp->link_gpio))
 193                 gpio_free(fp->link_gpio);
 194 err_regs:
 195         kfree(fp);
 196         return ret;
 197 }
 198 EXPORT_SYMBOL_GPL(fixed_phy_add);
 199
 200 static void fixed_phy_del(int phy_addr)
 201 {
 202         struct fixed_mdio_bus *fmb = &platform_fmb;
 203         struct fixed_phy *fp, *tmp;
 204
 205         list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
 206                 if (fp->addr == phy_addr) {
 207                         list_del(&fp->node);
 208                         if (gpio_is_valid(fp->link_gpio))
 209                                 gpio_free(fp->link_gpio);
 210                         kfree(fp);
 211                         return;
 212                 }
 213         }
 214 }
 215
 216 static int phy_fixed_addr;
 217 static DEFINE_SPINLOCK(phy_fixed_addr_lock);
 218
 219 struct phy_device *fixed_phy_register(unsigned int irq,
 220                                       struct fixed_phy_status *status,
 221                                       int link_gpio,
 222                                       struct device_node *np)
 223 {
 224         struct fixed_mdio_bus *fmb = &platform_fmb;
 225         struct phy_device *phy;
 226         int phy_addr;
 227         int ret;
 228
 229         if (!fmb->mii_bus || fmb->mii_bus->state != MDIOBUS_REGISTERED)
 230                 return ERR_PTR(-EPROBE_DEFER);
 231
 232         /* Get the next available PHY address, up to PHY_MAX_ADDR */
 233         spin_lock(&phy_fixed_addr_lock);
 234         if (phy_fixed_addr == PHY_MAX_ADDR) {
 235                 spin_unlock(&phy_fixed_addr_lock);
 236                 return ERR_PTR(-ENOSPC);
 237         }
 238         phy_addr = phy_fixed_addr++;
 239         spin_unlock(&phy_fixed_addr_lock);
 240
 241         ret = fixed_phy_add(irq, phy_addr, status, link_gpio);
 242         if (ret < 0)
 243                 return ERR_PTR(ret);
 244
 245         phy = get_phy_device(fmb->mii_bus, phy_addr, false);
 246         if (IS_ERR(phy)) {
 247                 fixed_phy_del(phy_addr);
 248                 return ERR_PTR(-EINVAL);
 249         }
 250
 251         /* propagate the fixed link values to struct phy_device */
 252         phy->link = status->link;
 253         if (status->link) {
 254                 phy->speed = status->speed;
 255                 phy->duplex = status->duplex;
 256                 phy->pause = status->pause;
 257                 phy->asym_pause = status->asym_pause;
 258         }
 259
 260         of_node_get(np);
 261         phy->mdio.dev.of_node = np;
 262         phy->is_pseudo_fixed_link = true;
 263
 264         switch (status->speed) {
 265         case SPEED_1000:
 266                 phy->supported = PHY_1000BT_FEATURES;
 267                 break;
 268         case SPEED_100:
 269                 phy->supported = PHY_100BT_FEATURES;
 270                 break;
 271         case SPEED_10:
 272         default:
 273                 phy->supported = PHY_10BT_FEATURES;
 274         }
 275
 276         ret = phy_device_register(phy);
 277         if (ret) {
 278                 phy_device_free(phy);
 279                 of_node_put(np);
 280                 fixed_phy_del(phy_addr);
 281                 return ERR_PTR(ret);
 282         }
 283
 284         return phy;
 285 }
 286 EXPORT_SYMBOL_GPL(fixed_phy_register);
 287
 288 void fixed_phy_unregister(struct phy_device *phy)
 289 {
 290         phy_device_remove(phy);
 291
 292         fixed_phy_del(phy->mdio.addr);
 293 }
 294 EXPORT_SYMBOL_GPL(fixed_phy_unregister);
 295
 296 static int __init fixed_mdio_bus_init(void)
 297 {
 298         struct fixed_mdio_bus *fmb = &platform_fmb;
 299         int ret;
 300
 301         pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0);
 302         if (IS_ERR(pdev)) {
 303                 ret = PTR_ERR(pdev);
 304                 goto err_pdev;
 305         }
 306
 307         fmb->mii_bus = mdiobus_alloc();
 308         if (fmb->mii_bus == NULL) {
 309                 ret = -ENOMEM;
 310                 goto err_mdiobus_reg;
 311         }
 312
 313         snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0");
 314         fmb->mii_bus->name = "Fixed MDIO Bus";
 315         fmb->mii_bus->priv = fmb;
 316         fmb->mii_bus->parent = &pdev->dev;
 317         fmb->mii_bus->read = &fixed_mdio_read;
 318         fmb->mii_bus->write = &fixed_mdio_write;
 319
 320         ret = mdiobus_register(fmb->mii_bus);
 321         if (ret)
 322                 goto err_mdiobus_alloc;
 323
 324         return 0;
 325
 326 err_mdiobus_alloc:
 327         mdiobus_free(fmb->mii_bus);
 328 err_mdiobus_reg:
 329         platform_device_unregister(pdev);
 330 err_pdev:
 331         return ret;
 332 }
 333 module_init(fixed_mdio_bus_init);
 334
 335 static void __exit fixed_mdio_bus_exit(void)
 336 {
 337         struct fixed_mdio_bus *fmb = &platform_fmb;
 338         struct fixed_phy *fp, *tmp;
 339
 340         mdiobus_unregister(fmb->mii_bus);
 341         mdiobus_free(fmb->mii_bus);
 342         platform_device_unregister(pdev);
 343
 344         list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
 345                 list_del(&fp->node);
 346                 kfree(fp);
 347         }
 348 }
 349 module_exit(fixed_mdio_bus_exit);
 350
 351 MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
 352 MODULE_AUTHOR("Vitaly Bordug");
 353 MODULE_LICENSE("GPL");