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
 25static void of_set_phy_supported(struct phy_device *phydev, u32 max_speed)
 26{
 27	/* The default values for phydev->supported are provided by the PHY
 28	 * driver "features" member, we want to reset to sane defaults fist
 29	 * before supporting higher speeds.
 30	 */
 31	phydev->supported &= PHY_DEFAULT_FEATURES;
 32
 33	switch (max_speed) {
 34	default:
 35		return;
 36
 37	case SPEED_1000:
 38		phydev->supported |= PHY_1000BT_FEATURES;
 39	case SPEED_100:
 40		phydev->supported |= PHY_100BT_FEATURES;
 41	case SPEED_10:
 42		phydev->supported |= PHY_10BT_FEATURES;
 43	}
 44}
 45
 46/* Extract the clause 22 phy ID from the compatible string of the form
 47 * ethernet-phy-idAAAA.BBBB */
 48static int of_get_phy_id(struct device_node *device, u32 *phy_id)
 49{
 50	struct property *prop;
 51	const char *cp;
 52	unsigned int upper, lower;
 53
 54	of_property_for_each_string(device, "compatible", prop, cp) {
 55		if (sscanf(cp, "ethernet-phy-id%4x.%4x", &upper, &lower) == 2) {
 56			*phy_id = ((upper & 0xFFFF) << 16) | (lower & 0xFFFF);
 57			return 0;
 58		}
 59	}
 60	return -EINVAL;
 61}
 62
 63static int of_mdiobus_register_phy(struct mii_bus *mdio, struct device_node *child,
 64				   u32 addr)
 65{
 66	struct phy_device *phy;
 67	bool is_c45;
 68	int rc;
 69	u32 max_speed = 0;
 70	u32 phy_id;
 71
 72	is_c45 = of_device_is_compatible(child,
 73					 "ethernet-phy-ieee802.3-c45");
 74
 75	if (!is_c45 && !of_get_phy_id(child, &phy_id))
 76		phy = phy_device_create(mdio, addr, phy_id, 0, NULL);
 77	else
 78		phy = get_phy_device(mdio, addr, is_c45);
 79	if (!phy || IS_ERR(phy))
 80		return 1;
 81
 82	rc = irq_of_parse_and_map(child, 0);
 83	if (rc > 0) {
 84		phy->irq = rc;
 85		if (mdio->irq)
 86			mdio->irq[addr] = rc;
 87	} else {
 88		if (mdio->irq)
 89			phy->irq = mdio->irq[addr];
 90	}
 91
 92	/* Associate the OF node with the device structure so it
 93	 * can be looked up later */
 94	of_node_get(child);
 95	phy->dev.of_node = child;
 96
 97	/* All data is now stored in the phy struct;
 98	 * register it */
 99	rc = phy_device_register(phy);
100	if (rc) {
101		phy_device_free(phy);
102		of_node_put(child);
103		return 1;
104	}
105
106	/* Set phydev->supported based on the "max-speed" property
107	 * if present */
108	if (!of_property_read_u32(child, "max-speed", &max_speed))
109		of_set_phy_supported(phy, max_speed);
110
111	dev_dbg(&mdio->dev, "registered phy %s at address %i\n",
112		child->name, addr);
113
114	return 0;
115}
116
117/**
118 * of_mdiobus_register - Register mii_bus and create PHYs from the device tree
119 * @mdio: pointer to mii_bus structure
120 * @np: pointer to device_node of MDIO bus.
121 *
122 * This function registers the mii_bus structure and registers a phy_device
123 * for each child node of @np.
124 */
125int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
126{
127	struct device_node *child;
128	const __be32 *paddr;
129	u32 addr;
130	bool scanphys = false;
131	int rc, i, len;
132
133	/* Mask out all PHYs from auto probing.  Instead the PHYs listed in
134	 * the device tree are populated after the bus has been registered */
135	mdio->phy_mask = ~0;
136
137	/* Clear all the IRQ properties */
138	if (mdio->irq)
139		for (i=0; i<PHY_MAX_ADDR; i++)
140			mdio->irq[i] = PHY_POLL;
141
142	mdio->dev.of_node = np;
143
144	/* Register the MDIO bus */
145	rc = mdiobus_register(mdio);
146	if (rc)
147		return rc;
148
149	/* Loop over the child nodes and register a phy_device for each one */
150	for_each_available_child_of_node(np, child) {
151		/* A PHY must have a reg property in the range [0-31] */
152		paddr = of_get_property(child, "reg", &len);
153		if (!paddr || len < sizeof(*paddr)) {
154			scanphys = true;
155			dev_err(&mdio->dev, "%s has invalid PHY address\n",
156				child->full_name);
157			continue;
158		}
159
160		addr = be32_to_cpup(paddr);
161		if (addr >= PHY_MAX_ADDR) {
162			dev_err(&mdio->dev, "%s PHY address %i is too large\n",
163				child->full_name, addr);
164			continue;
165		}
166
167		rc = of_mdiobus_register_phy(mdio, child, addr);
168		if (rc)
169			continue;
170	}
171
172	if (!scanphys)
173		return 0;
174
175	/* auto scan for PHYs with empty reg property */
176	for_each_available_child_of_node(np, child) {
177		/* Skip PHYs with reg property set */
178		paddr = of_get_property(child, "reg", &len);
179		if (paddr)
180			continue;
181
182		for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
183			/* skip already registered PHYs */
184			if (mdio->phy_map[addr])
185				continue;
186
187			/* be noisy to encourage people to set reg property */
188			dev_info(&mdio->dev, "scan phy %s at address %i\n",
189				 child->name, addr);
190
191			rc = of_mdiobus_register_phy(mdio, child, addr);
192			if (rc)
193				continue;
194		}
195	}
196
197	return 0;
198}
199EXPORT_SYMBOL(of_mdiobus_register);
200
201/* Helper function for of_phy_find_device */
202static int of_phy_match(struct device *dev, void *phy_np)
203{
204	return dev->of_node == phy_np;
205}
206
207/**
208 * of_phy_find_device - Give a PHY node, find the phy_device
209 * @phy_np: Pointer to the phy's device tree node
210 *
211 * Returns a pointer to the phy_device.
212 */
213struct phy_device *of_phy_find_device(struct device_node *phy_np)
214{
215	struct device *d;
216	if (!phy_np)
217		return NULL;
218
219	d = bus_find_device(&mdio_bus_type, NULL, phy_np, of_phy_match);
220	return d ? to_phy_device(d) : NULL;
221}
222EXPORT_SYMBOL(of_phy_find_device);
223
224/**
225 * of_phy_connect - Connect to the phy described in the device tree
226 * @dev: pointer to net_device claiming the phy
227 * @phy_np: Pointer to device tree node for the PHY
228 * @hndlr: Link state callback for the network device
229 * @iface: PHY data interface type
230 *
231 * Returns a pointer to the phy_device if successful.  NULL otherwise
232 */
233struct phy_device *of_phy_connect(struct net_device *dev,
234				  struct device_node *phy_np,
235				  void (*hndlr)(struct net_device *), u32 flags,
236				  phy_interface_t iface)
237{
238	struct phy_device *phy = of_phy_find_device(phy_np);
239
240	if (!phy)
241		return NULL;
242
243	return phy_connect_direct(dev, phy, hndlr, iface) ? NULL : phy;
244}
245EXPORT_SYMBOL(of_phy_connect);
246
247/**
248 * of_phy_connect_fixed_link - Parse fixed-link property and return a dummy phy
249 * @dev: pointer to net_device claiming the phy
250 * @hndlr: Link state callback for the network device
251 * @iface: PHY data interface type
252 *
253 * This function is a temporary stop-gap and will be removed soon.  It is
254 * only to support the fs_enet, ucc_geth and gianfar Ethernet drivers.  Do
255 * not call this function from new drivers.
256 */
257struct phy_device *of_phy_connect_fixed_link(struct net_device *dev,
258					     void (*hndlr)(struct net_device *),
259					     phy_interface_t iface)
260{
261	struct device_node *net_np;
262	char bus_id[MII_BUS_ID_SIZE + 3];
263	struct phy_device *phy;
264	const __be32 *phy_id;
265	int sz;
266
267	if (!dev->dev.parent)
268		return NULL;
269
270	net_np = dev->dev.parent->of_node;
271	if (!net_np)
272		return NULL;
273
274	phy_id = of_get_property(net_np, "fixed-link", &sz);
275	if (!phy_id || sz < sizeof(*phy_id))
276		return NULL;
277
278	sprintf(bus_id, PHY_ID_FMT, "fixed-0", be32_to_cpu(phy_id[0]));
279
280	phy = phy_connect(dev, bus_id, hndlr, iface);
281	return IS_ERR(phy) ? NULL : phy;
282}
283EXPORT_SYMBOL(of_phy_connect_fixed_link);
284
285/**
286 * of_phy_attach - Attach to a PHY without starting the state machine
287 * @dev: pointer to net_device claiming the phy
288 * @phy_np: Node pointer for the PHY
289 * @flags: flags to pass to the PHY
290 * @iface: PHY data interface type
291 */
292struct phy_device *of_phy_attach(struct net_device *dev,
293				 struct device_node *phy_np, u32 flags,
294				 phy_interface_t iface)
295{
296	struct phy_device *phy = of_phy_find_device(phy_np);
297
298	if (!phy)
299		return NULL;
300
301	return phy_attach_direct(dev, phy, flags, iface) ? NULL : phy;
302}
303EXPORT_SYMBOL(of_phy_attach);