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_gpio.h>
  20 #include <linux/of_irq.h>
  21 #include <linux/of_mdio.h>
  22 #include <linux/of_net.h>
  23 #include <linux/module.h>
  24
  25 #define DEFAULT_GPIO_RESET_DELAY        10      /* in microseconds */
  26
  27 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
  28 MODULE_LICENSE("GPL");
  29
  30 /* Extract the clause 22 phy ID from the compatible string of the form
  31  * ethernet-phy-idAAAA.BBBB */
  32 static int of_get_phy_id(struct device_node *device, u32 *phy_id)
  33 {
  34         struct property *prop;
  35         const char *cp;
  36         unsigned int upper, lower;
  37
  38         of_property_for_each_string(device, "compatible", prop, cp) {
  39                 if (sscanf(cp, "ethernet-phy-id%4x.%4x", &upper, &lower) == 2) {
  40                         *phy_id = ((upper & 0xFFFF) << 16) | (lower & 0xFFFF);
  41                         return 0;
  42                 }
  43         }
  44         return -EINVAL;
  45 }
  46
  47 static int of_mdiobus_register_phy(struct mii_bus *mdio,
  48                                     struct device_node *child, u32 addr)
  49 {
  50         struct phy_device *phy;
  51         bool is_c45;
  52         int rc;
  53         u32 phy_id;
  54
  55         is_c45 = of_device_is_compatible(child,
  56                                          "ethernet-phy-ieee802.3-c45");
  57
  58         if (!is_c45 && !of_get_phy_id(child, &phy_id))
  59                 phy = phy_device_create(mdio, addr, phy_id, 0, NULL);
  60         else
  61                 phy = get_phy_device(mdio, addr, is_c45);
  62         if (IS_ERR(phy))
  63                 return PTR_ERR(phy);
  64
  65         rc = of_irq_get(child, 0);
  66         if (rc == -EPROBE_DEFER) {
  67                 phy_device_free(phy);
  68                 return rc;
  69         }
  70         if (rc > 0) {
  71                 phy->irq = rc;
  72                 mdio->irq[addr] = rc;
  73         } else {
  74                 phy->irq = mdio->irq[addr];
  75         }
  76
  77         if (of_property_read_bool(child, "broken-turn-around"))
  78                 mdio->phy_ignore_ta_mask |= 1 << addr;
  79
  80         of_property_read_u32(child, "reset-assert-us",
  81                              &phy->mdio.reset_assert_delay);
  82         of_property_read_u32(child, "reset-deassert-us",
  83                              &phy->mdio.reset_deassert_delay);
  84
  85         /* Associate the OF node with the device structure so it
  86          * can be looked up later */
  87         of_node_get(child);
  88         phy->mdio.dev.of_node = child;
  89         phy->mdio.dev.fwnode = of_fwnode_handle(child);
  90
  91         /* All data is now stored in the phy struct;
  92          * register it */
  93         rc = phy_device_register(phy);
  94         if (rc) {
  95                 phy_device_free(phy);
  96                 of_node_put(child);
  97                 return rc;
  98         }
  99
 100         dev_dbg(&mdio->dev, "registered phy %pOFn at address %i\n",
 101                 child, addr);
 102         return 0;
 103 }
 104
 105 static int of_mdiobus_register_device(struct mii_bus *mdio,
 106                                       struct device_node *child, u32 addr)
 107 {
 108         struct mdio_device *mdiodev;
 109         int rc;
 110
 111         mdiodev = mdio_device_create(mdio, addr);
 112         if (IS_ERR(mdiodev))
 113                 return PTR_ERR(mdiodev);
 114
 115         /* Associate the OF node with the device structure so it
 116          * can be looked up later.
 117          */
 118         of_node_get(child);
 119         mdiodev->dev.of_node = child;
 120         mdiodev->dev.fwnode = of_fwnode_handle(child);
 121
 122         /* All data is now stored in the mdiodev struct; register it. */
 123         rc = mdio_device_register(mdiodev);
 124         if (rc) {
 125                 mdio_device_free(mdiodev);
 126                 of_node_put(child);
 127                 return rc;
 128         }
 129
 130         dev_dbg(&mdio->dev, "registered mdio device %pOFn at address %i\n",
 131                 child, addr);
 132         return 0;
 133 }
 134
 135 /* The following is a list of PHY compatible strings which appear in
 136  * some DTBs. The compatible string is never matched against a PHY
 137  * driver, so is pointless. We only expect devices which are not PHYs
 138  * to have a compatible string, so they can be matched to an MDIO
 139  * driver.  Encourage users to upgrade their DT blobs to remove these.
 140  */
 141 static const struct of_device_id whitelist_phys[] = {
 142         { .compatible = "brcm,40nm-ephy" },
 143         { .compatible = "broadcom,bcm5241" },
 144         { .compatible = "marvell,88E1111", },
 145         { .compatible = "marvell,88e1116", },
 146         { .compatible = "marvell,88e1118", },
 147         { .compatible = "marvell,88e1145", },
 148         { .compatible = "marvell,88e1149r", },
 149         { .compatible = "marvell,88e1310", },
 150         { .compatible = "marvell,88E1510", },
 151         { .compatible = "marvell,88E1514", },
 152         { .compatible = "moxa,moxart-rtl8201cp", },
 153         {}
 154 };
 155
 156 /*
 157  * Return true if the child node is for a phy. It must either:
 158  * o Compatible string of "ethernet-phy-idX.X"
 159  * o Compatible string of "ethernet-phy-ieee802.3-c45"
 160  * o Compatible string of "ethernet-phy-ieee802.3-c22"
 161  * o In the white list above (and issue a warning)
 162  * o No compatibility string
 163  *
 164  * A device which is not a phy is expected to have a compatible string
 165  * indicating what sort of device it is.
 166  */
 167 static bool of_mdiobus_child_is_phy(struct device_node *child)
 168 {
 169         u32 phy_id;
 170
 171         if (of_get_phy_id(child, &phy_id) != -EINVAL)
 172                 return true;
 173
 174         if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c45"))
 175                 return true;
 176
 177         if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c22"))
 178                 return true;
 179
 180         if (of_match_node(whitelist_phys, child)) {
 181                 pr_warn(FW_WARN
 182                         "%pOF: Whitelisted compatible string. Please remove\n",
 183                         child);
 184                 return true;
 185         }
 186
 187         if (!of_find_property(child, "compatible", NULL))
 188                 return true;
 189
 190         return false;
 191 }
 192
 193 /**
 194  * of_mdiobus_register - Register mii_bus and create PHYs from the device tree
 195  * @mdio: pointer to mii_bus structure
 196  * @np: pointer to device_node of MDIO bus.
 197  *
 198  * This function registers the mii_bus structure and registers a phy_device
 199  * for each child node of @np.
 200  */
 201 int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
 202 {
 203         struct device_node *child;
 204         bool scanphys = false;
 205         int addr, rc;
 206
 207         if (!np)
 208                 return mdiobus_register(mdio);
 209
 210         /* Do not continue if the node is disabled */
 211         if (!of_device_is_available(np))
 212                 return -ENODEV;
 213
 214         /* Mask out all PHYs from auto probing.  Instead the PHYs listed in
 215          * the device tree are populated after the bus has been registered */
 216         mdio->phy_mask = ~0;
 217
 218         mdio->dev.of_node = np;
 219         mdio->dev.fwnode = of_fwnode_handle(np);
 220
 221         /* Get bus level PHY reset GPIO details */
 222         mdio->reset_delay_us = DEFAULT_GPIO_RESET_DELAY;
 223         of_property_read_u32(np, "reset-delay-us", &mdio->reset_delay_us);
 224
 225         /* Register the MDIO bus */
 226         rc = mdiobus_register(mdio);
 227         if (rc)
 228                 return rc;
 229
 230         /* Loop over the child nodes and register a phy_device for each phy */
 231         for_each_available_child_of_node(np, child) {
 232                 addr = of_mdio_parse_addr(&mdio->dev, child);
 233                 if (addr < 0) {
 234                         scanphys = true;
 235                         continue;
 236                 }
 237
 238                 if (of_mdiobus_child_is_phy(child))
 239                         rc = of_mdiobus_register_phy(mdio, child, addr);
 240                 else
 241                         rc = of_mdiobus_register_device(mdio, child, addr);
 242
 243                 if (rc == -ENODEV)
 244                         dev_err(&mdio->dev,
 245                                 "MDIO device at address %d is missing.\n",
 246                                 addr);
 247                 else if (rc)
 248                         goto unregister;
 249         }
 250
 251         if (!scanphys)
 252                 return 0;
 253
 254         /* auto scan for PHYs with empty reg property */
 255         for_each_available_child_of_node(np, child) {
 256                 /* Skip PHYs with reg property set */
 257                 if (of_find_property(child, "reg", NULL))
 258                         continue;
 259
 260                 for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
 261                         /* skip already registered PHYs */
 262                         if (mdiobus_is_registered_device(mdio, addr))
 263                                 continue;
 264
 265                         /* be noisy to encourage people to set reg property */
 266                         dev_info(&mdio->dev, "scan phy %pOFn at address %i\n",
 267                                  child, addr);
 268
 269                         if (of_mdiobus_child_is_phy(child)) {
 270                                 rc = of_mdiobus_register_phy(mdio, child, addr);
 271                                 if (rc && rc != -ENODEV)
 272                                         goto unregister;
 273                         }
 274                 }
 275         }
 276
 277         return 0;
 278
 279 unregister:
 280         mdiobus_unregister(mdio);
 281         return rc;
 282 }
 283 EXPORT_SYMBOL(of_mdiobus_register);
 284
 285 /* Helper function for of_phy_find_device */
 286 static int of_phy_match(struct device *dev, void *phy_np)
 287 {
 288         return dev->of_node == phy_np;
 289 }
 290
 291 /**
 292  * of_phy_find_device - Give a PHY node, find the phy_device
 293  * @phy_np: Pointer to the phy's device tree node
 294  *
 295  * If successful, returns a pointer to the phy_device with the embedded
 296  * struct device refcount incremented by one, or NULL on failure.
 297  */
 298 struct phy_device *of_phy_find_device(struct device_node *phy_np)
 299 {
 300         struct device *d;
 301         struct mdio_device *mdiodev;
 302
 303         if (!phy_np)
 304                 return NULL;
 305
 306         d = bus_find_device(&mdio_bus_type, NULL, phy_np, of_phy_match);
 307         if (d) {
 308                 mdiodev = to_mdio_device(d);
 309                 if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY)
 310                         return to_phy_device(d);
 311                 put_device(d);
 312         }
 313
 314         return NULL;
 315 }
 316 EXPORT_SYMBOL(of_phy_find_device);
 317
 318 /**
 319  * of_phy_connect - Connect to the phy described in the device tree
 320  * @dev: pointer to net_device claiming the phy
 321  * @phy_np: Pointer to device tree node for the PHY
 322  * @hndlr: Link state callback for the network device
 323  * @flags: flags to pass to the PHY
 324  * @iface: PHY data interface type
 325  *
 326  * If successful, returns a pointer to the phy_device with the embedded
 327  * struct device refcount incremented by one, or NULL on failure. The
 328  * refcount must be dropped by calling phy_disconnect() or phy_detach().
 329  */
 330 struct phy_device *of_phy_connect(struct net_device *dev,
 331                                   struct device_node *phy_np,
 332                                   void (*hndlr)(struct net_device *), u32 flags,
 333                                   phy_interface_t iface)
 334 {
 335         struct phy_device *phy = of_phy_find_device(phy_np);
 336         int ret;
 337
 338         if (!phy)
 339                 return NULL;
 340
 341         phy->dev_flags = flags;
 342
 343         ret = phy_connect_direct(dev, phy, hndlr, iface);
 344
 345         /* refcount is held by phy_connect_direct() on success */
 346         put_device(&phy->mdio.dev);
 347
 348         return ret ? NULL : phy;
 349 }
 350 EXPORT_SYMBOL(of_phy_connect);
 351
 352 /**
 353  * of_phy_get_and_connect
 354  * - Get phy node and connect to the phy described in the device tree
 355  * @dev: pointer to net_device claiming the phy
 356  * @np: Pointer to device tree node for the net_device claiming the phy
 357  * @hndlr: Link state callback for the network device
 358  *
 359  * If successful, returns a pointer to the phy_device with the embedded
 360  * struct device refcount incremented by one, or NULL on failure. The
 361  * refcount must be dropped by calling phy_disconnect() or phy_detach().
 362  */
 363 struct phy_device *of_phy_get_and_connect(struct net_device *dev,
 364                                           struct device_node *np,
 365                                           void (*hndlr)(struct net_device *))
 366 {
 367         phy_interface_t iface;
 368         struct device_node *phy_np;
 369         struct phy_device *phy;
 370         int ret;
 371
 372         iface = of_get_phy_mode(np);
 373         if (iface < 0)
 374                 return NULL;
 375         if (of_phy_is_fixed_link(np)) {
 376                 ret = of_phy_register_fixed_link(np);
 377                 if (ret < 0) {
 378                         netdev_err(dev, "broken fixed-link specification\n");
 379                         return NULL;
 380                 }
 381                 phy_np = of_node_get(np);
 382         } else {
 383                 phy_np = of_parse_phandle(np, "phy-handle", 0);
 384                 if (!phy_np)
 385                         return NULL;
 386         }
 387
 388         phy = of_phy_connect(dev, phy_np, hndlr, 0, iface);
 389
 390         of_node_put(phy_np);
 391
 392         return phy;
 393 }
 394 EXPORT_SYMBOL(of_phy_get_and_connect);
 395
 396 /**
 397  * of_phy_attach - Attach to a PHY without starting the state machine
 398  * @dev: pointer to net_device claiming the phy
 399  * @phy_np: Node pointer for the PHY
 400  * @flags: flags to pass to the PHY
 401  * @iface: PHY data interface type
 402  *
 403  * If successful, returns a pointer to the phy_device with the embedded
 404  * struct device refcount incremented by one, or NULL on failure. The
 405  * refcount must be dropped by calling phy_disconnect() or phy_detach().
 406  */
 407 struct phy_device *of_phy_attach(struct net_device *dev,
 408                                  struct device_node *phy_np, u32 flags,
 409                                  phy_interface_t iface)
 410 {
 411         struct phy_device *phy = of_phy_find_device(phy_np);
 412         int ret;
 413
 414         if (!phy)
 415                 return NULL;
 416
 417         ret = phy_attach_direct(dev, phy, flags, iface);
 418
 419         /* refcount is held by phy_attach_direct() on success */
 420         put_device(&phy->mdio.dev);
 421
 422         return ret ? NULL : phy;
 423 }
 424 EXPORT_SYMBOL(of_phy_attach);
 425
 426 /*
 427  * of_phy_is_fixed_link() and of_phy_register_fixed_link() must
 428  * support two DT bindings:
 429  * - the old DT binding, where 'fixed-link' was a property with 5
 430  *   cells encoding various informations about the fixed PHY
 431  * - the new DT binding, where 'fixed-link' is a sub-node of the
 432  *   Ethernet device.
 433  */
 434 bool of_phy_is_fixed_link(struct device_node *np)
 435 {
 436         struct device_node *dn;
 437         int len, err;
 438         const char *managed;
 439
 440         /* New binding */
 441         dn = of_get_child_by_name(np, "fixed-link");
 442         if (dn) {
 443                 of_node_put(dn);
 444                 return true;
 445         }
 446
 447         err = of_property_read_string(np, "managed", &managed);
 448         if (err == 0 && strcmp(managed, "auto") != 0)
 449                 return true;
 450
 451         /* Old binding */
 452         if (of_get_property(np, "fixed-link", &len) &&
 453             len == (5 * sizeof(__be32)))
 454                 return true;
 455
 456         return false;
 457 }
 458 EXPORT_SYMBOL(of_phy_is_fixed_link);
 459
 460 int of_phy_register_fixed_link(struct device_node *np)
 461 {
 462         struct fixed_phy_status status = {};
 463         struct device_node *fixed_link_node;
 464         u32 fixed_link_prop[5];
 465         const char *managed;
 466         int link_gpio = -1;
 467
 468         if (of_property_read_string(np, "managed", &managed) == 0 &&
 469             strcmp(managed, "in-band-status") == 0) {
 470                 /* status is zeroed, namely its .link member */
 471                 goto register_phy;
 472         }
 473
 474         /* New binding */
 475         fixed_link_node = of_get_child_by_name(np, "fixed-link");
 476         if (fixed_link_node) {
 477                 status.link = 1;
 478                 status.duplex = of_property_read_bool(fixed_link_node,
 479                                                       "full-duplex");
 480                 if (of_property_read_u32(fixed_link_node, "speed",
 481                                          &status.speed)) {
 482                         of_node_put(fixed_link_node);
 483                         return -EINVAL;
 484                 }
 485                 status.pause = of_property_read_bool(fixed_link_node, "pause");
 486                 status.asym_pause = of_property_read_bool(fixed_link_node,
 487                                                           "asym-pause");
 488                 link_gpio = of_get_named_gpio_flags(fixed_link_node,
 489                                                     "link-gpios", 0, NULL);
 490                 of_node_put(fixed_link_node);
 491                 if (link_gpio == -EPROBE_DEFER)
 492                         return -EPROBE_DEFER;
 493
 494                 goto register_phy;
 495         }
 496
 497         /* Old binding */
 498         if (of_property_read_u32_array(np, "fixed-link", fixed_link_prop,
 499                                        ARRAY_SIZE(fixed_link_prop)) == 0) {
 500                 status.link = 1;
 501                 status.duplex = fixed_link_prop[1];
 502                 status.speed  = fixed_link_prop[2];
 503                 status.pause  = fixed_link_prop[3];
 504                 status.asym_pause = fixed_link_prop[4];
 505                 goto register_phy;
 506         }
 507
 508         return -ENODEV;
 509
 510 register_phy:
 511         return PTR_ERR_OR_ZERO(fixed_phy_register(PHY_POLL, &status, link_gpio,
 512                                                   np));
 513 }
 514 EXPORT_SYMBOL(of_phy_register_fixed_link);
 515
 516 void of_phy_deregister_fixed_link(struct device_node *np)
 517 {
 518         struct phy_device *phydev;
 519
 520         phydev = of_phy_find_device(np);
 521         if (!phydev)
 522                 return;
 523
 524         fixed_phy_unregister(phydev);
 525
 526         put_device(&phydev->mdio.dev);  /* of_phy_find_device() */
 527         phy_device_free(phydev);        /* fixed_phy_register() */
 528 }
 529 EXPORT_SYMBOL(of_phy_deregister_fixed_link);