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 void 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         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         ret = swphy_validate_state(status);
 164         if (ret < 0)
 165                 return ret;
 166
 167         fp = kzalloc(sizeof(*fp), GFP_KERNEL);
 168         if (!fp)
 169                 return -ENOMEM;
 170
 171         memset(fp->regs, 0xFF,  sizeof(fp->regs[0]) * MII_REGS_NUM);
 172
 173         if (irq != PHY_POLL)
 174                 fmb->mii_bus->irq[phy_addr] = irq;
 175
 176         fp->addr = phy_addr;
 177         fp->status = *status;
 178         fp->link_gpio = link_gpio;
 179
 180         if (gpio_is_valid(fp->link_gpio)) {
 181                 ret = gpio_request_one(fp->link_gpio, GPIOF_DIR_IN,
 182                                        "fixed-link-gpio-link");
 183                 if (ret)
 184                         goto err_regs;
 185         }
 186
 187         fixed_phy_update_regs(fp);
 188
 189         list_add_tail(&fp->node, &fmb->phys);
 190
 191         return 0;
 192
 193 err_regs:
 194         kfree(fp);
 195         return ret;
 196 }
 197 EXPORT_SYMBOL_GPL(fixed_phy_add);
 198
 199 static void fixed_phy_del(int phy_addr)
 200 {
 201         struct fixed_mdio_bus *fmb = &platform_fmb;
 202         struct fixed_phy *fp, *tmp;
 203
 204         list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
 205                 if (fp->addr == phy_addr) {
 206                         list_del(&fp->node);
 207                         if (gpio_is_valid(fp->link_gpio))
 208                                 gpio_free(fp->link_gpio);
 209                         kfree(fp);
 210                         return;
 211                 }
 212         }
 213 }
 214
 215 static int phy_fixed_addr;
 216 static DEFINE_SPINLOCK(phy_fixed_addr_lock);
 217
 218 struct phy_device *fixed_phy_register(unsigned int irq,
 219                                       struct fixed_phy_status *status,
 220                                       int link_gpio,
 221                                       struct device_node *np)
 222 {
 223         struct fixed_mdio_bus *fmb = &platform_fmb;
 224         struct phy_device *phy;
 225         int phy_addr;
 226         int ret;
 227
 228         if (!fmb->mii_bus || fmb->mii_bus->state != MDIOBUS_REGISTERED)
 229                 return ERR_PTR(-EPROBE_DEFER);
 230
 231         /* Get the next available PHY address, up to PHY_MAX_ADDR */
 232         spin_lock(&phy_fixed_addr_lock);
 233         if (phy_fixed_addr == PHY_MAX_ADDR) {
 234                 spin_unlock(&phy_fixed_addr_lock);
 235                 return ERR_PTR(-ENOSPC);
 236         }
 237         phy_addr = phy_fixed_addr++;
 238         spin_unlock(&phy_fixed_addr_lock);
 239
 240         ret = fixed_phy_add(irq, phy_addr, status, link_gpio);
 241         if (ret < 0)
 242                 return ERR_PTR(ret);
 243
 244         phy = get_phy_device(fmb->mii_bus, phy_addr, false);
 245         if (IS_ERR(phy)) {
 246                 fixed_phy_del(phy_addr);
 247                 return ERR_PTR(-EINVAL);
 248         }
 249
 250         /* propagate the fixed link values to struct phy_device */
 251         phy->link = status->link;
 252         if (status->link) {
 253                 phy->speed = status->speed;
 254                 phy->duplex = status->duplex;
 255                 phy->pause = status->pause;
 256                 phy->asym_pause = status->asym_pause;
 257         }
 258
 259         of_node_get(np);
 260         phy->mdio.dev.of_node = np;
 261         phy->is_pseudo_fixed_link = true;
 262
 263         switch (status->speed) {
 264         case SPEED_1000:
 265                 phy->supported = PHY_1000BT_FEATURES;
 266                 break;
 267         case SPEED_100:
 268                 phy->supported = PHY_100BT_FEATURES;
 269                 break;
 270         case SPEED_10:
 271         default:
 272                 phy->supported = PHY_10BT_FEATURES;
 273         }
 274
 275         ret = phy_device_register(phy);
 276         if (ret) {
 277                 phy_device_free(phy);
 278                 of_node_put(np);
 279                 fixed_phy_del(phy_addr);
 280                 return ERR_PTR(ret);
 281         }
 282
 283         return phy;
 284 }
 285 EXPORT_SYMBOL_GPL(fixed_phy_register);
 286
 287 void fixed_phy_unregister(struct phy_device *phy)
 288 {
 289         phy_device_remove(phy);
 290
 291         fixed_phy_del(phy->mdio.addr);
 292 }
 293 EXPORT_SYMBOL_GPL(fixed_phy_unregister);
 294
 295 static int __init fixed_mdio_bus_init(void)
 296 {
 297         struct fixed_mdio_bus *fmb = &platform_fmb;
 298         int ret;
 299
 300         pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0);
 301         if (IS_ERR(pdev)) {
 302                 ret = PTR_ERR(pdev);
 303                 goto err_pdev;
 304         }
 305
 306         fmb->mii_bus = mdiobus_alloc();
 307         if (fmb->mii_bus == NULL) {
 308                 ret = -ENOMEM;
 309                 goto err_mdiobus_reg;
 310         }
 311
 312         snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0");
 313         fmb->mii_bus->name = "Fixed MDIO Bus";
 314         fmb->mii_bus->priv = fmb;
 315         fmb->mii_bus->parent = &pdev->dev;
 316         fmb->mii_bus->read = &fixed_mdio_read;
 317         fmb->mii_bus->write = &fixed_mdio_write;
 318
 319         ret = mdiobus_register(fmb->mii_bus);
 320         if (ret)
 321                 goto err_mdiobus_alloc;
 322
 323         return 0;
 324
 325 err_mdiobus_alloc:
 326         mdiobus_free(fmb->mii_bus);
 327 err_mdiobus_reg:
 328         platform_device_unregister(pdev);
 329 err_pdev:
 330         return ret;
 331 }
 332 module_init(fixed_mdio_bus_init);
 333
 334 static void __exit fixed_mdio_bus_exit(void)
 335 {
 336         struct fixed_mdio_bus *fmb = &platform_fmb;
 337         struct fixed_phy *fp, *tmp;
 338
 339         mdiobus_unregister(fmb->mii_bus);
 340         mdiobus_free(fmb->mii_bus);
 341         platform_device_unregister(pdev);
 342
 343         list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
 344                 list_del(&fp->node);
 345                 kfree(fp);
 346         }
 347 }
 348 module_exit(fixed_mdio_bus_exit);
 349
 350 MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
 351 MODULE_AUTHOR("Vitaly Bordug");
 352 MODULE_LICENSE("GPL");