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