drivers/of/of_mdio.c

   1 /*
   2  * OF helpers for the MDIO (Ethernet PHY) API
   3  *
   4  * Copyright (c) 2009 Secret Lab Technologies, Ltd.
   5  *
   6  * This file is released under the GPLv2
   7  *
   8  * This file provides helper functions for extracting PHY device information
   9  * out of the OpenFirmware device tree and using it to populate an mii_bus.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/device.h>
  14 #include <linux/netdevice.h>
  15 #include <linux/err.h>
  16 #include <linux/phy.h>
  17 #include <linux/phy_fixed.h>
  18 #include <linux/of.h>
  19 #include <linux/of_irq.h>
  20 #include <linux/of_mdio.h>
  21 #include <linux/of_net.h>
  22 #include <linux/module.h>
  23
  24 #define DEFAULT_GPIO_RESET_DELAY        10      /* in microseconds */
  25
  26 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
  27 MODULE_LICENSE("GPL");
  28
  29 /* Extract the clause 22 phy ID from the compatible string of the form
  30  * ethernet-phy-idAAAA.BBBB */
  31 static int of_get_phy_id(struct device_node *device, u32 *phy_id)
  32 {
  33         struct property *prop;
  34         const char *cp;
  35         unsigned int upper, lower;
  36
  37         of_property_for_each_string(device, "compatible", prop, cp) {
  38                 if (sscanf(cp, "ethernet-phy-id%4x.%4x", &upper, &lower) == 2) {
  39                         *phy_id = ((upper & 0xFFFF) << 16) | (lower & 0xFFFF);
  40                         return 0;
  41                 }
  42         }
  43         return -EINVAL;
  44 }
  45
  46 static int of_mdiobus_register_phy(struct mii_bus *mdio,
  47                                     struct device_node *child, u32 addr)
  48 {
  49         struct phy_device *phy;
  50         bool is_c45;
  51         int rc;
  52         u32 phy_id;
  53
  54         is_c45 = of_device_is_compatible(child,
  55                                          "ethernet-phy-ieee802.3-c45");
  56
  57         if (!is_c45 && !of_get_phy_id(child, &phy_id))
  58                 phy = phy_device_create(mdio, addr, phy_id, 0, NULL);
  59         else
  60                 phy = get_phy_device(mdio, addr, is_c45);
  61         if (IS_ERR(phy))
  62                 return PTR_ERR(phy);
  63
  64         rc = of_irq_get(child, 0);
  65         if (rc == -EPROBE_DEFER) {
  66                 phy_device_free(phy);
  67                 return rc;
  68         }
  69         if (rc > 0) {
  70                 phy->irq = rc;
  71                 mdio->irq[addr] = rc;
  72         } else {
  73                 phy->irq = mdio->irq[addr];
  74         }
  75
  76         if (of_property_read_bool(child, "broken-turn-around"))
  77                 mdio->phy_ignore_ta_mask |= 1 << addr;
  78
  79         of_property_read_u32(child, "reset-assert-us",
  80                              &phy->mdio.reset_assert_delay);
  81         of_property_read_u32(child, "reset-deassert-us",
  82                              &phy->mdio.reset_deassert_delay);
  83
  84         /* Associate the OF node with the device structure so it
  85          * can be looked up later */
  86         of_node_get(child);
  87         phy->mdio.dev.of_node = child;
  88         phy->mdio.dev.fwnode = of_fwnode_handle(child);
  89
  90         /* All data is now stored in the phy struct;
  91          * register it */
  92         rc = phy_device_register(phy);
  93         if (rc) {
  94                 phy_device_free(phy);
  95                 of_node_put(child);
  96                 return rc;
  97         }
  98
  99         dev_dbg(&mdio->dev, "registered phy %pOFn at address %i\n",
 100                 child, addr);
 101         return 0;
 102 }
 103
 104 static int of_mdiobus_register_device(struct mii_bus *mdio,
 105                                       struct device_node *child, u32 addr)
 106 {
 107         struct mdio_device *mdiodev;
 108         int rc;
 109
 110         mdiodev = mdio_device_create(mdio, addr);
 111         if (IS_ERR(mdiodev))
 112                 return PTR_ERR(mdiodev);
 113
 114         /* Associate the OF node with the device structure so it
 115          * can be looked up later.
 116          */
 117         of_node_get(child);
 118         mdiodev->dev.of_node = child;
 119         mdiodev->dev.fwnode = of_fwnode_handle(child);
 120
 121         /* All data is now stored in the mdiodev struct; register it. */
 122         rc = mdio_device_register(mdiodev);
 123         if (rc) {
 124                 mdio_device_free(mdiodev);
 125                 of_node_put(child);
 126                 return rc;
 127         }
 128
 129         dev_dbg(&mdio->dev, "registered mdio device %pOFn at address %i\n",
 130                 child, addr);
 131         return 0;
 132 }
 133
 134 /* The following is a list of PHY compatible strings which appear in
 135  * some DTBs. The compatible string is never matched against a PHY
 136  * driver, so is pointless. We only expect devices which are not PHYs
 137  * to have a compatible string, so they can be matched to an MDIO
 138  * driver.  Encourage users to upgrade their DT blobs to remove these.
 139  */
 140 static const struct of_device_id whitelist_phys[] = {
 141         { .compatible = "brcm,40nm-ephy" },
 142         { .compatible = "broadcom,bcm5241" },
 143         { .compatible = "marvell,88E1111", },
 144         { .compatible = "marvell,88e1116", },
 145         { .compatible = "marvell,88e1118", },
 146         { .compatible = "marvell,88e1145", },
 147         { .compatible = "marvell,88e1149r", },
 148         { .compatible = "marvell,88e1310", },
 149         { .compatible = "marvell,88E1510", },
 150         { .compatible = "marvell,88E1514", },
 151         { .compatible = "moxa,moxart-rtl8201cp", },
 152         {}
 153 };
 154
 155 /*
 156  * Return true if the child node is for a phy. It must either:
 157  * o Compatible string of "ethernet-phy-idX.X"
 158  * o Compatible string of "ethernet-phy-ieee802.3-c45"
 159  * o Compatible string of "ethernet-phy-ieee802.3-c22"
 160  * o In the white list above (and issue a warning)
 161  * o No compatibility string
 162  *
 163  * A device which is not a phy is expected to have a compatible string
 164  * indicating what sort of device it is.
 165  */
 166 static bool of_mdiobus_child_is_phy(struct device_node *child)
 167 {
 168         u32 phy_id;
 169
 170         if (of_get_phy_id(child, &phy_id) != -EINVAL)
 171                 return true;
 172
 173         if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c45"))
 174                 return true;
 175
 176         if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c22"))
 177                 return true;
 178
 179         if (of_match_node(whitelist_phys, child)) {
 180                 pr_warn(FW_WARN
 181                         "%pOF: Whitelisted compatible string. Please remove\n",
 182                         child);
 183                 return true;
 184         }
 185
 186         if (!of_find_property(child, "compatible", NULL))
 187                 return true;
 188
 189         return false;
 190 }
 191
 192 /**
 193  * of_mdiobus_register - Register mii_bus and create PHYs from the device tree
 194  * @mdio: pointer to mii_bus structure
 195  * @np: pointer to device_node of MDIO bus.
 196  *
 197  * This function registers the mii_bus structure and registers a phy_device
 198  * for each child node of @np.
 199  */
 200 int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
 201 {
 202         struct device_node *child;
 203         bool scanphys = false;
 204         int addr, rc;
 205
 206         if (!np)
 207                 return mdiobus_register(mdio);
 208
 209         /* Do not continue if the node is disabled */
 210         if (!of_device_is_available(np))
 211                 return -ENODEV;
 212
 213         /* Mask out all PHYs from auto probing.  Instead the PHYs listed in
 214          * the device tree are populated after the bus has been registered */
 215         mdio->phy_mask = ~0;
 216
 217         mdio->dev.of_node = np;
 218         mdio->dev.fwnode = of_fwnode_handle(np);
 219
 220         /* Get bus level PHY reset GPIO details */
 221         mdio->reset_delay_us = DEFAULT_GPIO_RESET_DELAY;
 222         of_property_read_u32(np, "reset-delay-us", &mdio->reset_delay_us);
 223
 224         /* Register the MDIO bus */
 225         rc = mdiobus_register(mdio);
 226         if (rc)
 227                 return rc;
 228
 229         /* Loop over the child nodes and register a phy_device for each phy */
 230         for_each_available_child_of_node(np, child) {
 231                 addr = of_mdio_parse_addr(&mdio->dev, child);
 232                 if (addr < 0) {
 233                         scanphys = true;
 234                         continue;
 235                 }
 236
 237                 if (of_mdiobus_child_is_phy(child))
 238                         rc = of_mdiobus_register_phy(mdio, child, addr);
 239                 else
 240                         rc = of_mdiobus_register_device(mdio, child, addr);
 241
 242                 if (rc == -ENODEV)
 243                         dev_err(&mdio->dev,
 244                                 "MDIO device at address %d is missing.\n",
 245                                 addr);
 246                 else if (rc)
 247                         goto unregister;
 248         }
 249
 250         if (!scanphys)
 251                 return 0;
 252
 253         /* auto scan for PHYs with empty reg property */
 254         for_each_available_child_of_node(np, child) {
 255                 /* Skip PHYs with reg property set */
 256                 if (of_find_property(child, "reg", NULL))
 257                         continue;
 258
 259                 for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
 260                         /* skip already registered PHYs */
 261                         if (mdiobus_is_registered_device(mdio, addr))
 262                                 continue;
 263
 264                         /* be noisy to encourage people to set reg property */
 265                         dev_info(&mdio->dev, "scan phy %pOFn at address %i\n",
 266                                  child, addr);
 267
 268                         if (of_mdiobus_child_is_phy(child)) {
 269                                 rc = of_mdiobus_register_phy(mdio, child, addr);
 270                                 if (rc && rc != -ENODEV)
 271                                         goto unregister;
 272                         }
 273                 }
 274         }
 275
 276         return 0;
 277
 278 unregister:
 279         mdiobus_unregister(mdio);
 280         return rc;
 281 }
 282 EXPORT_SYMBOL(of_mdiobus_register);
 283
 284 /* Helper function for of_phy_find_device */
 285 static int of_phy_match(struct device *dev, void *phy_np)
 286 {
 287         return dev->of_node == phy_np;
 288 }
 289
 290 /**
 291  * of_phy_find_device - Give a PHY node, find the phy_device
 292  * @phy_np: Pointer to the phy's device tree node
 293  *
 294  * If successful, returns a pointer to the phy_device with the embedded
 295  * struct device refcount incremented by one, or NULL on failure.
 296  */
 297 struct phy_device *of_phy_find_device(struct device_node *phy_np)
 298 {
 299         struct device *d;
 300         struct mdio_device *mdiodev;
 301
 302         if (!phy_np)
 303                 return NULL;
 304
 305         d = bus_find_device(&mdio_bus_type, NULL, phy_np, of_phy_match);
 306         if (d) {
 307                 mdiodev = to_mdio_device(d);
 308                 if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY)
 309                         return to_phy_device(d);
 310                 put_device(d);
 311         }
 312
 313         return NULL;
 314 }
 315 EXPORT_SYMBOL(of_phy_find_device);
 316
 317 /**
 318  * of_phy_connect - Connect to the phy described in the device tree
 319  * @dev: pointer to net_device claiming the phy
 320  * @phy_np: Pointer to device tree node for the PHY
 321  * @hndlr: Link state callback for the network device
 322  * @flags: flags to pass to the PHY
 323  * @iface: PHY data interface type
 324  *
 325  * If successful, returns a pointer to the phy_device with the embedded
 326  * struct device refcount incremented by one, or NULL on failure. The
 327  * refcount must be dropped by calling phy_disconnect() or phy_detach().
 328  */
 329 struct phy_device *of_phy_connect(struct net_device *dev,
 330                                   struct device_node *phy_np,
 331                                   void (*hndlr)(struct net_device *), u32 flags,
 332                                   phy_interface_t iface)
 333 {
 334         struct phy_device *phy = of_phy_find_device(phy_np);
 335         int ret;
 336
 337         if (!phy)
 338                 return NULL;
 339
 340         phy->dev_flags = flags;
 341
 342         ret = phy_connect_direct(dev, phy, hndlr, iface);
 343
 344         /* refcount is held by phy_connect_direct() on success */
 345         put_device(&phy->mdio.dev);
 346
 347         return ret ? NULL : phy;
 348 }
 349 EXPORT_SYMBOL(of_phy_connect);
 350
 351 /**
 352  * of_phy_get_and_connect
 353  * - Get phy node and connect to the phy described in the device tree
 354  * @dev: pointer to net_device claiming the phy
 355  * @np: Pointer to device tree node for the net_device claiming the phy
 356  * @hndlr: Link state callback for the network device
 357  *
 358  * If successful, returns a pointer to the phy_device with the embedded
 359  * struct device refcount incremented by one, or NULL on failure. The
 360  * refcount must be dropped by calling phy_disconnect() or phy_detach().
 361  */
 362 struct phy_device *of_phy_get_and_connect(struct net_device *dev,
 363                                           struct device_node *np,
 364                                           void (*hndlr)(struct net_device *))
 365 {
 366         phy_interface_t iface;
 367         struct device_node *phy_np;
 368         struct phy_device *phy;
 369         int ret;
 370
 371         iface = of_get_phy_mode(np);
 372         if (iface < 0)
 373                 return NULL;
 374         if (of_phy_is_fixed_link(np)) {
 375                 ret = of_phy_register_fixed_link(np);
 376                 if (ret < 0) {
 377                         netdev_err(dev, "broken fixed-link specification\n");
 378                         return NULL;
 379                 }
 380                 phy_np = of_node_get(np);
 381         } else {
 382                 phy_np = of_parse_phandle(np, "phy-handle", 0);
 383                 if (!phy_np)
 384                         return NULL;
 385         }
 386
 387         phy = of_phy_connect(dev, phy_np, hndlr, 0, iface);
 388
 389         of_node_put(phy_np);
 390
 391         return phy;
 392 }
 393 EXPORT_SYMBOL(of_phy_get_and_connect);
 394
 395 /**
 396  * of_phy_attach - Attach to a PHY without starting the state machine
 397  * @dev: pointer to net_device claiming the phy
 398  * @phy_np: Node pointer for the PHY
 399  * @flags: flags to pass to the PHY
 400  * @iface: PHY data interface type
 401  *
 402  * If successful, returns a pointer to the phy_device with the embedded
 403  * struct device refcount incremented by one, or NULL on failure. The
 404  * refcount must be dropped by calling phy_disconnect() or phy_detach().
 405  */
 406 struct phy_device *of_phy_attach(struct net_device *dev,
 407                                  struct device_node *phy_np, u32 flags,
 408                                  phy_interface_t iface)
 409 {
 410         struct phy_device *phy = of_phy_find_device(phy_np);
 411         int ret;
 412
 413         if (!phy)
 414                 return NULL;
 415
 416         ret = phy_attach_direct(dev, phy, flags, iface);
 417
 418         /* refcount is held by phy_attach_direct() on success */
 419         put_device(&phy->mdio.dev);
 420
 421         return ret ? NULL : phy;
 422 }
 423 EXPORT_SYMBOL(of_phy_attach);
 424
 425 /*
 426  * of_phy_is_fixed_link() and of_phy_register_fixed_link() must
 427  * support two DT bindings:
 428  * - the old DT binding, where 'fixed-link' was a property with 5
 429  *   cells encoding various informations about the fixed PHY
 430  * - the new DT binding, where 'fixed-link' is a sub-node of the
 431  *   Ethernet device.
 432  */
 433 bool of_phy_is_fixed_link(struct device_node *np)
 434 {
 435         struct device_node *dn;
 436         int len, err;
 437         const char *managed;
 438
 439         /* New binding */
 440         dn = of_get_child_by_name(np, "fixed-link");
 441         if (dn) {
 442                 of_node_put(dn);
 443                 return true;
 444         }
 445
 446         err = of_property_read_string(np, "managed", &managed);
 447         if (err == 0 && strcmp(managed, "auto") != 0)
 448                 return true;
 449
 450         /* Old binding */
 451         if (of_get_property(np, "fixed-link", &len) &&
 452             len == (5 * sizeof(__be32)))
 453                 return true;
 454
 455         return false;
 456 }
 457 EXPORT_SYMBOL(of_phy_is_fixed_link);
 458
 459 int of_phy_register_fixed_link(struct device_node *np)
 460 {
 461         struct fixed_phy_status status = {};
 462         struct device_node *fixed_link_node;
 463         u32 fixed_link_prop[5];
 464         const char *managed;
 465
 466         if (of_property_read_string(np, "managed", &managed) == 0 &&
 467             strcmp(managed, "in-band-status") == 0) {
 468                 /* status is zeroed, namely its .link member */
 469                 goto register_phy;
 470         }
 471
 472         /* New binding */
 473         fixed_link_node = of_get_child_by_name(np, "fixed-link");
 474         if (fixed_link_node) {
 475                 status.link = 1;
 476                 status.duplex = of_property_read_bool(fixed_link_node,
 477                                                       "full-duplex");
 478                 if (of_property_read_u32(fixed_link_node, "speed",
 479                                          &status.speed)) {
 480                         of_node_put(fixed_link_node);
 481                         return -EINVAL;
 482                 }
 483                 status.pause = of_property_read_bool(fixed_link_node, "pause");
 484                 status.asym_pause = of_property_read_bool(fixed_link_node,
 485                                                           "asym-pause");
 486                 of_node_put(fixed_link_node);
 487
 488                 goto register_phy;
 489         }
 490
 491         /* Old binding */
 492         if (of_property_read_u32_array(np, "fixed-link", fixed_link_prop,
 493                                        ARRAY_SIZE(fixed_link_prop)) == 0) {
 494                 status.link = 1;
 495                 status.duplex = fixed_link_prop[1];
 496                 status.speed  = fixed_link_prop[2];
 497                 status.pause  = fixed_link_prop[3];
 498                 status.asym_pause = fixed_link_prop[4];
 499                 goto register_phy;
 500         }
 501
 502         return -ENODEV;
 503
 504 register_phy:
 505         return PTR_ERR_OR_ZERO(fixed_phy_register(PHY_POLL, &status, np));
 506 }
 507 EXPORT_SYMBOL(of_phy_register_fixed_link);
 508
 509 void of_phy_deregister_fixed_link(struct device_node *np)
 510 {
 511         struct phy_device *phydev;
 512
 513         phydev = of_phy_find_device(np);
 514         if (!phydev)
 515                 return;
 516
 517         fixed_phy_unregister(phydev);
 518
 519         put_device(&phydev->mdio.dev);  /* of_phy_find_device() */
 520         phy_device_free(phydev);        /* fixed_phy_register() */
 521 }
 522 EXPORT_SYMBOL(of_phy_deregister_fixed_link);