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