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
87		/* Associate the OF node with the device structure so it
88		 * can be looked up later */
89		of_node_get(child);
90		phy->dev.of_node = child;
91
92		/* All data is now stored in the phy struct; register it */
93		rc = phy_device_register(phy);
94		if (rc) {
95			phy_device_free(phy);
96			of_node_put(child);
97			continue;
98		}
99
100		dev_dbg(&mdio->dev, "registered phy %s at address %i\n",
101			child->name, addr);
102	}
103
104	return 0;
105}
106EXPORT_SYMBOL(of_mdiobus_register);
107
108/* Helper function for of_phy_find_device */
109static int of_phy_match(struct device *dev, void *phy_np)
110{
111	return dev->of_node == phy_np;
112}
113
114/**
115 * of_phy_find_device - Give a PHY node, find the phy_device
116 * @phy_np: Pointer to the phy's device tree node
117 *
118 * Returns a pointer to the phy_device.
119 */
120struct phy_device *of_phy_find_device(struct device_node *phy_np)
121{
122	struct device *d;
123	if (!phy_np)
124		return NULL;
125
126	d = bus_find_device(&mdio_bus_type, NULL, phy_np, of_phy_match);
127	return d ? to_phy_device(d) : NULL;
128}
129EXPORT_SYMBOL(of_phy_find_device);
130
131/**
132 * of_phy_connect - Connect to the phy described in the device tree
133 * @dev: pointer to net_device claiming the phy
134 * @phy_np: Pointer to device tree node for the PHY
135 * @hndlr: Link state callback for the network device
136 * @iface: PHY data interface type
137 *
138 * Returns a pointer to the phy_device if successful.  NULL otherwise
139 */
140struct phy_device *of_phy_connect(struct net_device *dev,
141				  struct device_node *phy_np,
142				  void (*hndlr)(struct net_device *), u32 flags,
143				  phy_interface_t iface)
144{
145	struct phy_device *phy = of_phy_find_device(phy_np);
146
147	if (!phy)
148		return NULL;
149
150	return phy_connect_direct(dev, phy, hndlr, flags, iface) ? NULL : phy;
151}
152EXPORT_SYMBOL(of_phy_connect);
153
154/**
155 * of_phy_connect_fixed_link - Parse fixed-link property and return a dummy phy
156 * @dev: pointer to net_device claiming the phy
157 * @hndlr: Link state callback for the network device
158 * @iface: PHY data interface type
159 *
160 * This function is a temporary stop-gap and will be removed soon.  It is
161 * only to support the fs_enet, ucc_geth and gianfar Ethernet drivers.  Do
162 * not call this function from new drivers.
163 */
164struct phy_device *of_phy_connect_fixed_link(struct net_device *dev,
165					     void (*hndlr)(struct net_device *),
166					     phy_interface_t iface)
167{
168	struct device_node *net_np;
169	char bus_id[MII_BUS_ID_SIZE + 3];
170	struct phy_device *phy;
171	const __be32 *phy_id;
172	int sz;
173
174	if (!dev->dev.parent)
175		return NULL;
176
177	net_np = dev->dev.parent->of_node;
178	if (!net_np)
179		return NULL;
180
181	phy_id = of_get_property(net_np, "fixed-link", &sz);
182	if (!phy_id || sz < sizeof(*phy_id))
183		return NULL;
184
185	sprintf(bus_id, PHY_ID_FMT, "fixed-0", be32_to_cpu(phy_id[0]));
186
187	phy = phy_connect(dev, bus_id, hndlr, 0, iface);
188	return IS_ERR(phy) ? NULL : phy;
189}
190EXPORT_SYMBOL(of_phy_connect_fixed_link);
191