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/of.h>
  18 #include <linux/of_irq.h>
  19 #include <linux/of_mdio.h>
  20 #include <linux/module.h>
  21
  22 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
  23 MODULE_LICENSE("GPL");
  24
  25 /**
  26  * of_mdiobus_register - Register mii_bus and create PHYs from the device tree
  27  * @mdio: pointer to mii_bus structure
  28  * @np: pointer to device_node of MDIO bus.
  29  *
  30  * This function registers the mii_bus structure and registers a phy_device
  31  * for each child node of @np.
  32  */
  33 int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
  34 {
  35         struct phy_device *phy;
  36         struct device_node *child;
  37         int rc, i;
  38
  39         /* Mask out all PHYs from auto probing.  Instead the PHYs listed in
  40          * the device tree are populated after the bus has been registered */
  41         mdio->phy_mask = ~0;
  42
  43         /* Clear all the IRQ properties */
  44         if (mdio->irq)
  45                 for (i=0; i<PHY_MAX_ADDR; i++)
  46                         mdio->irq[i] = PHY_POLL;
  47
  48         mdio->dev.of_node = np;
  49
  50         /* Register the MDIO bus */
  51         rc = mdiobus_register(mdio);
  52         if (rc)
  53                 return rc;
  54
  55         /* Loop over the child nodes and register a phy_device for each one */
  56         for_each_child_of_node(np, child) {
  57                 const __be32 *paddr;
  58                 u32 addr;
  59                 int len;
  60
  61                 /* A PHY must have a reg property in the range [0-31] */
  62                 paddr = of_get_property(child, "reg", &len);
  63                 if (!paddr || len < sizeof(*paddr)) {
  64                         dev_err(&mdio->dev, "%s has invalid PHY address\n",
  65                                 child->full_name);
  66                         continue;
  67                 }
  68
  69                 addr = be32_to_cpup(paddr);
  70                 if (addr >= 32) {
  71                         dev_err(&mdio->dev, "%s PHY address %i is too large\n",
  72                                 child->full_name, addr);
  73                         continue;
  74                 }
  75
  76                 if (mdio->irq) {
  77                         mdio->irq[addr] = irq_of_parse_and_map(child, 0);
  78                         if (!mdio->irq[addr])
  79                                 mdio->irq[addr] = PHY_POLL;
  80                 }
  81
  82                 phy = get_phy_device(mdio, addr);
  83                 if (!phy || IS_ERR(phy)) {
  84                         dev_err(&mdio->dev, "error probing PHY at address %i\n",
  85                                 addr);
  86                         continue;
  87                 }
  88
  89                 /* Associate the OF node with the device structure so it
  90                  * can be looked up later */
  91                 of_node_get(child);
  92                 phy->dev.of_node = child;
  93
  94                 /* All data is now stored in the phy struct; register it */
  95                 rc = phy_device_register(phy);
  96                 if (rc) {
  97                         phy_device_free(phy);
  98                         of_node_put(child);
  99                         continue;
 100                 }
 101
 102                 dev_dbg(&mdio->dev, "registered phy %s at address %i\n",
 103                         child->name, addr);
 104         }
 105
 106         return 0;
 107 }
 108 EXPORT_SYMBOL(of_mdiobus_register);
 109
 110 /* Helper function for of_phy_find_device */
 111 static int of_phy_match(struct device *dev, void *phy_np)
 112 {
 113         return dev->of_node == phy_np;
 114 }
 115
 116 /**
 117  * of_phy_find_device - Give a PHY node, find the phy_device
 118  * @phy_np: Pointer to the phy's device tree node
 119  *
 120  * Returns a pointer to the phy_device.
 121  */
 122 struct phy_device *of_phy_find_device(struct device_node *phy_np)
 123 {
 124         struct device *d;
 125         if (!phy_np)
 126                 return NULL;
 127
 128         d = bus_find_device(&mdio_bus_type, NULL, phy_np, of_phy_match);
 129         return d ? to_phy_device(d) : NULL;
 130 }
 131 EXPORT_SYMBOL(of_phy_find_device);
 132
 133 /**
 134  * of_phy_connect - Connect to the phy described in the device tree
 135  * @dev: pointer to net_device claiming the phy
 136  * @phy_np: Pointer to device tree node for the PHY
 137  * @hndlr: Link state callback for the network device
 138  * @iface: PHY data interface type
 139  *
 140  * Returns a pointer to the phy_device if successful.  NULL otherwise
 141  */
 142 struct phy_device *of_phy_connect(struct net_device *dev,
 143                                   struct device_node *phy_np,
 144                                   void (*hndlr)(struct net_device *), u32 flags,
 145                                   phy_interface_t iface)
 146 {
 147         struct phy_device *phy = of_phy_find_device(phy_np);
 148
 149         if (!phy)
 150                 return NULL;
 151
 152         return phy_connect_direct(dev, phy, hndlr, flags, iface) ? NULL : phy;
 153 }
 154 EXPORT_SYMBOL(of_phy_connect);
 155
 156 /**
 157  * of_phy_connect_fixed_link - Parse fixed-link property and return a dummy phy
 158  * @dev: pointer to net_device claiming the phy
 159  * @hndlr: Link state callback for the network device
 160  * @iface: PHY data interface type
 161  *
 162  * This function is a temporary stop-gap and will be removed soon.  It is
 163  * only to support the fs_enet, ucc_geth and gianfar Ethernet drivers.  Do
 164  * not call this function from new drivers.
 165  */
 166 struct phy_device *of_phy_connect_fixed_link(struct net_device *dev,
 167                                              void (*hndlr)(struct net_device *),
 168                                              phy_interface_t iface)
 169 {
 170         struct device_node *net_np;
 171         char bus_id[MII_BUS_ID_SIZE + 3];
 172         struct phy_device *phy;
 173         const __be32 *phy_id;
 174         int sz;
 175
 176         if (!dev->dev.parent)
 177                 return NULL;
 178
 179         net_np = dev->dev.parent->of_node;
 180         if (!net_np)
 181                 return NULL;
 182
 183         phy_id = of_get_property(net_np, "fixed-link", &sz);
 184         if (!phy_id || sz < sizeof(*phy_id))
 185                 return NULL;
 186
 187         sprintf(bus_id, PHY_ID_FMT, "fixed-0", be32_to_cpu(phy_id[0]));
 188
 189         phy = phy_connect(dev, bus_id, hndlr, 0, iface);
 190         return IS_ERR(phy) ? NULL : phy;
 191 }
 192 EXPORT_SYMBOL(of_phy_connect_fixed_link);