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_add(unsigned int irq, int phy_addr,
 119                   struct fixed_phy_status *status,
 120                   int link_gpio)
 121 {
 122         int ret;
 123         struct fixed_mdio_bus *fmb = &platform_fmb;
 124         struct fixed_phy *fp;
 125
 126         ret = swphy_validate_state(status);
 127         if (ret < 0)
 128                 return ret;
 129
 130         fp = kzalloc(sizeof(*fp), GFP_KERNEL);
 131         if (!fp)
 132                 return -ENOMEM;
 133
 134         seqcount_init(&fp->seqcount);
 135
 136         if (irq != PHY_POLL)
 137                 fmb->mii_bus->irq[phy_addr] = irq;
 138
 139         fp->addr = phy_addr;
 140         fp->status = *status;
 141         fp->link_gpio = link_gpio;
 142
 143         if (gpio_is_valid(fp->link_gpio)) {
 144                 ret = gpio_request_one(fp->link_gpio, GPIOF_DIR_IN,
 145                                        "fixed-link-gpio-link");
 146                 if (ret)
 147                         goto err_regs;
 148         }
 149
 150         fixed_phy_update(fp);
 151
 152         list_add_tail(&fp->node, &fmb->phys);
 153
 154         return 0;
 155
 156 err_regs:
 157         kfree(fp);
 158         return ret;
 159 }
 160 EXPORT_SYMBOL_GPL(fixed_phy_add);
 161
 162 static DEFINE_IDA(phy_fixed_ida);
 163
 164 static void fixed_phy_del(int phy_addr)
 165 {
 166         struct fixed_mdio_bus *fmb = &platform_fmb;
 167         struct fixed_phy *fp, *tmp;
 168
 169         list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
 170                 if (fp->addr == phy_addr) {
 171                         list_del(&fp->node);
 172                         if (gpio_is_valid(fp->link_gpio))
 173                                 gpio_free(fp->link_gpio);
 174                         kfree(fp);
 175                         ida_simple_remove(&phy_fixed_ida, phy_addr);
 176                         return;
 177                 }
 178         }
 179 }
 180
 181 struct phy_device *fixed_phy_register(unsigned int irq,
 182                                       struct fixed_phy_status *status,
 183                                       int link_gpio,
 184                                       struct device_node *np)
 185 {
 186         struct fixed_mdio_bus *fmb = &platform_fmb;
 187         struct phy_device *phy;
 188         int phy_addr;
 189         int ret;
 190
 191         if (!fmb->mii_bus || fmb->mii_bus->state != MDIOBUS_REGISTERED)
 192                 return ERR_PTR(-EPROBE_DEFER);
 193
 194         /* Get the next available PHY address, up to PHY_MAX_ADDR */
 195         phy_addr = ida_simple_get(&phy_fixed_ida, 0, PHY_MAX_ADDR, GFP_KERNEL);
 196         if (phy_addr < 0)
 197                 return ERR_PTR(phy_addr);
 198
 199         ret = fixed_phy_add(irq, phy_addr, status, link_gpio);
 200         if (ret < 0) {
 201                 ida_simple_remove(&phy_fixed_ida, phy_addr);
 202                 return ERR_PTR(ret);
 203         }
 204
 205         phy = get_phy_device(fmb->mii_bus, phy_addr, false);
 206         if (IS_ERR(phy)) {
 207                 fixed_phy_del(phy_addr);
 208                 return ERR_PTR(-EINVAL);
 209         }
 210
 211         /* propagate the fixed link values to struct phy_device */
 212         phy->link = status->link;
 213         if (status->link) {
 214                 phy->speed = status->speed;
 215                 phy->duplex = status->duplex;
 216                 phy->pause = status->pause;
 217                 phy->asym_pause = status->asym_pause;
 218         }
 219
 220         of_node_get(np);
 221         phy->mdio.dev.of_node = np;
 222         phy->is_pseudo_fixed_link = true;
 223
 224         switch (status->speed) {
 225         case SPEED_1000:
 226                 phy->supported = PHY_1000BT_FEATURES;
 227                 break;
 228         case SPEED_100:
 229                 phy->supported = PHY_100BT_FEATURES;
 230                 break;
 231         case SPEED_10:
 232         default:
 233                 phy->supported = PHY_10BT_FEATURES;
 234         }
 235
 236         ret = phy_device_register(phy);
 237         if (ret) {
 238                 phy_device_free(phy);
 239                 of_node_put(np);
 240                 fixed_phy_del(phy_addr);
 241                 return ERR_PTR(ret);
 242         }
 243
 244         return phy;
 245 }
 246 EXPORT_SYMBOL_GPL(fixed_phy_register);
 247
 248 void fixed_phy_unregister(struct phy_device *phy)
 249 {
 250         phy_device_remove(phy);
 251         of_node_put(phy->mdio.dev.of_node);
 252         fixed_phy_del(phy->mdio.addr);
 253 }
 254 EXPORT_SYMBOL_GPL(fixed_phy_unregister);
 255
 256 static int __init fixed_mdio_bus_init(void)
 257 {
 258         struct fixed_mdio_bus *fmb = &platform_fmb;
 259         int ret;
 260
 261         pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0);
 262         if (IS_ERR(pdev)) {
 263                 ret = PTR_ERR(pdev);
 264                 goto err_pdev;
 265         }
 266
 267         fmb->mii_bus = mdiobus_alloc();
 268         if (fmb->mii_bus == NULL) {
 269                 ret = -ENOMEM;
 270                 goto err_mdiobus_reg;
 271         }
 272
 273         snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0");
 274         fmb->mii_bus->name = "Fixed MDIO Bus";
 275         fmb->mii_bus->priv = fmb;
 276         fmb->mii_bus->parent = &pdev->dev;
 277         fmb->mii_bus->read = &fixed_mdio_read;
 278         fmb->mii_bus->write = &fixed_mdio_write;
 279
 280         ret = mdiobus_register(fmb->mii_bus);
 281         if (ret)
 282                 goto err_mdiobus_alloc;
 283
 284         return 0;
 285
 286 err_mdiobus_alloc:
 287         mdiobus_free(fmb->mii_bus);
 288 err_mdiobus_reg:
 289         platform_device_unregister(pdev);
 290 err_pdev:
 291         return ret;
 292 }
 293 module_init(fixed_mdio_bus_init);
 294
 295 static void __exit fixed_mdio_bus_exit(void)
 296 {
 297         struct fixed_mdio_bus *fmb = &platform_fmb;
 298         struct fixed_phy *fp, *tmp;
 299
 300         mdiobus_unregister(fmb->mii_bus);
 301         mdiobus_free(fmb->mii_bus);
 302         platform_device_unregister(pdev);
 303
 304         list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
 305                 list_del(&fp->node);
 306                 kfree(fp);
 307         }
 308         ida_destroy(&phy_fixed_ida);
 309 }
 310 module_exit(fixed_mdio_bus_exit);
 311
 312 MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
 313 MODULE_AUTHOR("Vitaly Bordug");
 314 MODULE_LICENSE("GPL");