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
 22MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
 23MODULE_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 */
 33int 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}
108EXPORT_SYMBOL(of_mdiobus_register);
109
110/* Helper function for of_phy_find_device */
111static 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 */
122struct 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}
131EXPORT_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 */
142struct 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}
154EXPORT_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 */
166struct 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}
192EXPORT_SYMBOL(of_phy_connect_fixed_link);