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