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/module.h>
  23
  24 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
  25 MODULE_LICENSE("GPL");
  26
  27 /* Extract the clause 22 phy ID from the compatible string of the form
  28  * ethernet-phy-idAAAA.BBBB */
  29 static int of_get_phy_id(struct device_node *device, u32 *phy_id)
  30 {
  31         struct property *prop;
  32         const char *cp;
  33         unsigned int upper, lower;
  34
  35         of_property_for_each_string(device, "compatible", prop, cp) {
  36                 if (sscanf(cp, "ethernet-phy-id%4x.%4x", &upper, &lower) == 2) {
  37                         *phy_id = ((upper & 0xFFFF) << 16) | (lower & 0xFFFF);
  38                         return 0;
  39                 }
  40         }
  41         return -EINVAL;
  42 }
  43
  44 static int of_mdiobus_register_phy(struct mii_bus *mdio, struct device_node *child,
  45                                    u32 addr)
  46 {
  47         struct phy_device *phy;
  48         bool is_c45;
  49         int rc;
  50         u32 phy_id;
  51
  52         is_c45 = of_device_is_compatible(child,
  53                                          "ethernet-phy-ieee802.3-c45");
  54
  55         if (!is_c45 && !of_get_phy_id(child, &phy_id))
  56                 phy = phy_device_create(mdio, addr, phy_id, 0, NULL);
  57         else
  58                 phy = get_phy_device(mdio, addr, is_c45);
  59         if (!phy || IS_ERR(phy))
  60                 return 1;
  61
  62         rc = irq_of_parse_and_map(child, 0);
  63         if (rc > 0) {
  64                 phy->irq = rc;
  65                 mdio->irq[addr] = rc;
  66         } else {
  67                 phy->irq = mdio->irq[addr];
  68         }
  69
  70         if (of_property_read_bool(child, "broken-turn-around"))
  71                 mdio->phy_ignore_ta_mask |= 1 << addr;
  72
  73         /* Associate the OF node with the device structure so it
  74          * can be looked up later */
  75         of_node_get(child);
  76         phy->mdio.dev.of_node = child;
  77
  78         /* All data is now stored in the phy struct;
  79          * register it */
  80         rc = phy_device_register(phy);
  81         if (rc) {
  82                 phy_device_free(phy);
  83                 of_node_put(child);
  84                 return 1;
  85         }
  86
  87         dev_dbg(&mdio->dev, "registered phy %s at address %i\n",
  88                 child->name, addr);
  89
  90         return 0;
  91 }
  92
  93 static int of_mdiobus_register_device(struct mii_bus *mdio,
  94                                       struct device_node *child,
  95                                       u32 addr)
  96 {
  97         struct mdio_device *mdiodev;
  98         int rc;
  99
 100         mdiodev = mdio_device_create(mdio, addr);
 101         if (!mdiodev || IS_ERR(mdiodev))
 102                 return 1;
 103
 104         /* Associate the OF node with the device structure so it
 105          * can be looked up later.
 106          */
 107         of_node_get(child);
 108         mdiodev->dev.of_node = child;
 109
 110         /* All data is now stored in the mdiodev struct; register it. */
 111         rc = mdio_device_register(mdiodev);
 112         if (rc) {
 113                 mdio_device_free(mdiodev);
 114                 of_node_put(child);
 115                 return 1;
 116         }
 117
 118         dev_dbg(&mdio->dev, "registered mdio device %s at address %i\n",
 119                 child->name, addr);
 120
 121         return 0;
 122 }
 123
 124 int of_mdio_parse_addr(struct device *dev, const struct device_node *np)
 125 {
 126         u32 addr;
 127         int ret;
 128
 129         ret = of_property_read_u32(np, "reg", &addr);
 130         if (ret < 0) {
 131                 dev_err(dev, "%s has invalid PHY address\n", np->full_name);
 132                 return ret;
 133         }
 134
 135         /* A PHY must have a reg property in the range [0-31] */
 136         if (addr >= PHY_MAX_ADDR) {
 137                 dev_err(dev, "%s PHY address %i is too large\n",
 138                         np->full_name, addr);
 139                 return -EINVAL;
 140         }
 141
 142         return addr;
 143 }
 144 EXPORT_SYMBOL(of_mdio_parse_addr);
 145
 146 /*
 147  * Return true if the child node is for a phy. It must either:
 148  * o Compatible string of "ethernet-phy-idX.X"
 149  * o Compatible string of "ethernet-phy-ieee802.3-c45"
 150  * o Compatible string of "ethernet-phy-ieee802.3-c22"
 151  * o No compatibility string
 152  *
 153  * A device which is not a phy is expected to have a compatible string
 154  * indicating what sort of device it is.
 155  */
 156 static bool of_mdiobus_child_is_phy(struct device_node *child)
 157 {
 158         u32 phy_id;
 159
 160         if (of_get_phy_id(child, &phy_id) != -EINVAL)
 161                 return true;
 162
 163         if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c45"))
 164                 return true;
 165
 166         if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c22"))
 167                 return true;
 168
 169         if (!of_find_property(child, "compatible", NULL))
 170                 return true;
 171
 172         return false;
 173 }
 174
 175 /**
 176  * of_mdiobus_register - Register mii_bus and create PHYs from the device tree
 177  * @mdio: pointer to mii_bus structure
 178  * @np: pointer to device_node of MDIO bus.
 179  *
 180  * This function registers the mii_bus structure and registers a phy_device
 181  * for each child node of @np.
 182  */
 183 int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
 184 {
 185         struct device_node *child;
 186         const __be32 *paddr;
 187         bool scanphys = false;
 188         int addr, rc;
 189
 190         /* Mask out all PHYs from auto probing.  Instead the PHYs listed in
 191          * the device tree are populated after the bus has been registered */
 192         mdio->phy_mask = ~0;
 193
 194         mdio->dev.of_node = np;
 195
 196         /* Register the MDIO bus */
 197         rc = mdiobus_register(mdio);
 198         if (rc)
 199                 return rc;
 200
 201         /* Loop over the child nodes and register a phy_device for each phy */
 202         for_each_available_child_of_node(np, child) {
 203                 addr = of_mdio_parse_addr(&mdio->dev, child);
 204                 if (addr < 0) {
 205                         scanphys = true;
 206                         continue;
 207                 }
 208
 209                 if (of_mdiobus_child_is_phy(child))
 210                         of_mdiobus_register_phy(mdio, child, addr);
 211                 else
 212                         of_mdiobus_register_device(mdio, child, addr);
 213         }
 214
 215         if (!scanphys)
 216                 return 0;
 217
 218         /* auto scan for PHYs with empty reg property */
 219         for_each_available_child_of_node(np, child) {
 220                 /* Skip PHYs with reg property set */
 221                 paddr = of_get_property(child, "reg", NULL);
 222                 if (paddr)
 223                         continue;
 224
 225                 for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
 226                         /* skip already registered PHYs */
 227                         if (mdiobus_is_registered_device(mdio, addr))
 228                                 continue;
 229
 230                         /* be noisy to encourage people to set reg property */
 231                         dev_info(&mdio->dev, "scan phy %s at address %i\n",
 232                                  child->name, addr);
 233
 234                         if (of_mdiobus_child_is_phy(child))
 235                                 of_mdiobus_register_phy(mdio, child, addr);
 236                 }
 237         }
 238
 239         return 0;
 240 }
 241 EXPORT_SYMBOL(of_mdiobus_register);
 242
 243 /* Helper function for of_phy_find_device */
 244 static int of_phy_match(struct device *dev, void *phy_np)
 245 {
 246         return dev->of_node == phy_np;
 247 }
 248
 249 /**
 250  * of_phy_find_device - Give a PHY node, find the phy_device
 251  * @phy_np: Pointer to the phy's device tree node
 252  *
 253  * If successful, returns a pointer to the phy_device with the embedded
 254  * struct device refcount incremented by one, or NULL on failure.
 255  */
 256 struct phy_device *of_phy_find_device(struct device_node *phy_np)
 257 {
 258         struct device *d;
 259         if (!phy_np)
 260                 return NULL;
 261
 262         d = bus_find_device(&mdio_bus_type, NULL, phy_np, of_phy_match);
 263         return d ? to_phy_device(d) : NULL;
 264 }
 265 EXPORT_SYMBOL(of_phy_find_device);
 266
 267 /**
 268  * of_phy_connect - Connect to the phy described in the device tree
 269  * @dev: pointer to net_device claiming the phy
 270  * @phy_np: Pointer to device tree node for the PHY
 271  * @hndlr: Link state callback for the network device
 272  * @iface: PHY data interface type
 273  *
 274  * If successful, returns a pointer to the phy_device with the embedded
 275  * struct device refcount incremented by one, or NULL on failure. The
 276  * refcount must be dropped by calling phy_disconnect() or phy_detach().
 277  */
 278 struct phy_device *of_phy_connect(struct net_device *dev,
 279                                   struct device_node *phy_np,
 280                                   void (*hndlr)(struct net_device *), u32 flags,
 281                                   phy_interface_t iface)
 282 {
 283         struct phy_device *phy = of_phy_find_device(phy_np);
 284         int ret;
 285
 286         if (!phy)
 287                 return NULL;
 288
 289         phy->dev_flags = flags;
 290
 291         ret = phy_connect_direct(dev, phy, hndlr, iface);
 292
 293         /* refcount is held by phy_connect_direct() on success */
 294         put_device(&phy->mdio.dev);
 295
 296         return ret ? NULL : phy;
 297 }
 298 EXPORT_SYMBOL(of_phy_connect);
 299
 300 /**
 301  * of_phy_attach - Attach to a PHY without starting the state machine
 302  * @dev: pointer to net_device claiming the phy
 303  * @phy_np: Node pointer for the PHY
 304  * @flags: flags to pass to the PHY
 305  * @iface: PHY data interface type
 306  *
 307  * If successful, returns a pointer to the phy_device with the embedded
 308  * struct device refcount incremented by one, or NULL on failure. The
 309  * refcount must be dropped by calling phy_disconnect() or phy_detach().
 310  */
 311 struct phy_device *of_phy_attach(struct net_device *dev,
 312                                  struct device_node *phy_np, u32 flags,
 313                                  phy_interface_t iface)
 314 {
 315         struct phy_device *phy = of_phy_find_device(phy_np);
 316         int ret;
 317
 318         if (!phy)
 319                 return NULL;
 320
 321         ret = phy_attach_direct(dev, phy, flags, iface);
 322
 323         /* refcount is held by phy_attach_direct() on success */
 324         put_device(&phy->mdio.dev);
 325
 326         return ret ? NULL : phy;
 327 }
 328 EXPORT_SYMBOL(of_phy_attach);
 329
 330 #if defined(CONFIG_FIXED_PHY)
 331 /*
 332  * of_phy_is_fixed_link() and of_phy_register_fixed_link() must
 333  * support two DT bindings:
 334  * - the old DT binding, where 'fixed-link' was a property with 5
 335  *   cells encoding various informations about the fixed PHY
 336  * - the new DT binding, where 'fixed-link' is a sub-node of the
 337  *   Ethernet device.
 338  */
 339 bool of_phy_is_fixed_link(struct device_node *np)
 340 {
 341         struct device_node *dn;
 342         int len, err;
 343         const char *managed;
 344
 345         /* New binding */
 346         dn = of_get_child_by_name(np, "fixed-link");
 347         if (dn) {
 348                 of_node_put(dn);
 349                 return true;
 350         }
 351
 352         err = of_property_read_string(np, "managed", &managed);
 353         if (err == 0 && strcmp(managed, "auto") != 0)
 354                 return true;
 355
 356         /* Old binding */
 357         if (of_get_property(np, "fixed-link", &len) &&
 358             len == (5 * sizeof(__be32)))
 359                 return true;
 360
 361         return false;
 362 }
 363 EXPORT_SYMBOL(of_phy_is_fixed_link);
 364
 365 int of_phy_register_fixed_link(struct device_node *np)
 366 {
 367         struct fixed_phy_status status = {};
 368         struct device_node *fixed_link_node;
 369         const __be32 *fixed_link_prop;
 370         int link_gpio;
 371         int len, err;
 372         struct phy_device *phy;
 373         const char *managed;
 374
 375         err = of_property_read_string(np, "managed", &managed);
 376         if (err == 0) {
 377                 if (strcmp(managed, "in-band-status") == 0) {
 378                         /* status is zeroed, namely its .link member */
 379                         phy = fixed_phy_register(PHY_POLL, &status, -1, np);
 380                         return IS_ERR(phy) ? PTR_ERR(phy) : 0;
 381                 }
 382         }
 383
 384         /* New binding */
 385         fixed_link_node = of_get_child_by_name(np, "fixed-link");
 386         if (fixed_link_node) {
 387                 status.link = 1;
 388                 status.duplex = of_property_read_bool(fixed_link_node,
 389                                                       "full-duplex");
 390                 if (of_property_read_u32(fixed_link_node, "speed", &status.speed))
 391                         return -EINVAL;
 392                 status.pause = of_property_read_bool(fixed_link_node, "pause");
 393                 status.asym_pause = of_property_read_bool(fixed_link_node,
 394                                                           "asym-pause");
 395                 link_gpio = of_get_named_gpio_flags(fixed_link_node,
 396                                                     "link-gpios", 0, NULL);
 397                 of_node_put(fixed_link_node);
 398                 if (link_gpio == -EPROBE_DEFER)
 399                         return -EPROBE_DEFER;
 400
 401                 phy = fixed_phy_register(PHY_POLL, &status, link_gpio, np);
 402                 return IS_ERR(phy) ? PTR_ERR(phy) : 0;
 403         }
 404
 405         /* Old binding */
 406         fixed_link_prop = of_get_property(np, "fixed-link", &len);
 407         if (fixed_link_prop && len == (5 * sizeof(__be32))) {
 408                 status.link = 1;
 409                 status.duplex = be32_to_cpu(fixed_link_prop[1]);
 410                 status.speed = be32_to_cpu(fixed_link_prop[2]);
 411                 status.pause = be32_to_cpu(fixed_link_prop[3]);
 412                 status.asym_pause = be32_to_cpu(fixed_link_prop[4]);
 413                 phy = fixed_phy_register(PHY_POLL, &status, -1, np);
 414                 return IS_ERR(phy) ? PTR_ERR(phy) : 0;
 415         }
 416
 417         return -ENODEV;
 418 }
 419 EXPORT_SYMBOL(of_phy_register_fixed_link);
 420 #endif