xref: /openbmc/linux/drivers/net/mdio/of_mdio.c (revision 65844828)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * OF helpers for the MDIO (Ethernet PHY) API
4  *
5  * Copyright (c) 2009 Secret Lab Technologies, Ltd.
6  *
7  * This file provides helper functions for extracting PHY device information
8  * out of the OpenFirmware device tree and using it to populate an mii_bus.
9  */
10 
11 #include <linux/device.h>
12 #include <linux/err.h>
13 #include <linux/fwnode_mdio.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/netdevice.h>
17 #include <linux/of.h>
18 #include <linux/of_irq.h>
19 #include <linux/of_mdio.h>
20 #include <linux/of_net.h>
21 #include <linux/phy.h>
22 #include <linux/phy_fixed.h>
23 
24 #define DEFAULT_GPIO_RESET_DELAY	10	/* in microseconds */
25 
26 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
27 MODULE_LICENSE("GPL");
28 
29 /* Extract the clause 22 phy ID from the compatible string of the form
30  * ethernet-phy-idAAAA.BBBB */
31 static int of_get_phy_id(struct device_node *device, u32 *phy_id)
32 {
33 	return fwnode_get_phy_id(of_fwnode_handle(device), phy_id);
34 }
35 
36 int of_mdiobus_phy_device_register(struct mii_bus *mdio, struct phy_device *phy,
37 				   struct device_node *child, u32 addr)
38 {
39 	return fwnode_mdiobus_phy_device_register(mdio, phy,
40 						  of_fwnode_handle(child),
41 						  addr);
42 }
43 EXPORT_SYMBOL(of_mdiobus_phy_device_register);
44 
45 static int of_mdiobus_register_phy(struct mii_bus *mdio,
46 				    struct device_node *child, u32 addr)
47 {
48 	return fwnode_mdiobus_register_phy(mdio, of_fwnode_handle(child), addr);
49 }
50 
51 static int of_mdiobus_register_device(struct mii_bus *mdio,
52 				      struct device_node *child, u32 addr)
53 {
54 	struct fwnode_handle *fwnode = of_fwnode_handle(child);
55 	struct mdio_device *mdiodev;
56 	int rc;
57 
58 	mdiodev = mdio_device_create(mdio, addr);
59 	if (IS_ERR(mdiodev))
60 		return PTR_ERR(mdiodev);
61 
62 	/* Associate the OF node with the device structure so it
63 	 * can be looked up later.
64 	 */
65 	fwnode_handle_get(fwnode);
66 	device_set_node(&mdiodev->dev, fwnode);
67 
68 	/* All data is now stored in the mdiodev struct; register it. */
69 	rc = mdio_device_register(mdiodev);
70 	if (rc) {
71 		device_set_node(&mdiodev->dev, NULL);
72 		fwnode_handle_put(fwnode);
73 		mdio_device_free(mdiodev);
74 		return rc;
75 	}
76 
77 	dev_dbg(&mdio->dev, "registered mdio device %pOFn at address %i\n",
78 		child, addr);
79 	return 0;
80 }
81 
82 /* The following is a list of PHY compatible strings which appear in
83  * some DTBs. The compatible string is never matched against a PHY
84  * driver, so is pointless. We only expect devices which are not PHYs
85  * to have a compatible string, so they can be matched to an MDIO
86  * driver.  Encourage users to upgrade their DT blobs to remove these.
87  */
88 static const struct of_device_id whitelist_phys[] = {
89 	{ .compatible = "brcm,40nm-ephy" },
90 	{ .compatible = "broadcom,bcm5241" },
91 	{ .compatible = "marvell,88E1111", },
92 	{ .compatible = "marvell,88e1116", },
93 	{ .compatible = "marvell,88e1118", },
94 	{ .compatible = "marvell,88e1145", },
95 	{ .compatible = "marvell,88e1149r", },
96 	{ .compatible = "marvell,88e1310", },
97 	{ .compatible = "marvell,88E1510", },
98 	{ .compatible = "marvell,88E1514", },
99 	{ .compatible = "moxa,moxart-rtl8201cp", },
100 	{}
101 };
102 
103 /*
104  * Return true if the child node is for a phy. It must either:
105  * o Compatible string of "ethernet-phy-idX.X"
106  * o Compatible string of "ethernet-phy-ieee802.3-c45"
107  * o Compatible string of "ethernet-phy-ieee802.3-c22"
108  * o In the white list above (and issue a warning)
109  * o No compatibility string
110  *
111  * A device which is not a phy is expected to have a compatible string
112  * indicating what sort of device it is.
113  */
114 bool of_mdiobus_child_is_phy(struct device_node *child)
115 {
116 	u32 phy_id;
117 
118 	if (of_get_phy_id(child, &phy_id) != -EINVAL)
119 		return true;
120 
121 	if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c45"))
122 		return true;
123 
124 	if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c22"))
125 		return true;
126 
127 	if (of_match_node(whitelist_phys, child)) {
128 		pr_warn(FW_WARN
129 			"%pOF: Whitelisted compatible string. Please remove\n",
130 			child);
131 		return true;
132 	}
133 
134 	if (!of_find_property(child, "compatible", NULL))
135 		return true;
136 
137 	return false;
138 }
139 EXPORT_SYMBOL(of_mdiobus_child_is_phy);
140 
141 /**
142  * of_mdiobus_register - Register mii_bus and create PHYs from the device tree
143  * @mdio: pointer to mii_bus structure
144  * @np: pointer to device_node of MDIO bus.
145  *
146  * This function registers the mii_bus structure and registers a phy_device
147  * for each child node of @np.
148  */
149 int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
150 {
151 	struct device_node *child;
152 	bool scanphys = false;
153 	int addr, rc;
154 
155 	if (!np)
156 		return mdiobus_register(mdio);
157 
158 	/* Do not continue if the node is disabled */
159 	if (!of_device_is_available(np))
160 		return -ENODEV;
161 
162 	/* Mask out all PHYs from auto probing.  Instead the PHYs listed in
163 	 * the device tree are populated after the bus has been registered */
164 	mdio->phy_mask = ~0;
165 
166 	device_set_node(&mdio->dev, of_fwnode_handle(np));
167 
168 	/* Get bus level PHY reset GPIO details */
169 	mdio->reset_delay_us = DEFAULT_GPIO_RESET_DELAY;
170 	of_property_read_u32(np, "reset-delay-us", &mdio->reset_delay_us);
171 	mdio->reset_post_delay_us = 0;
172 	of_property_read_u32(np, "reset-post-delay-us", &mdio->reset_post_delay_us);
173 
174 	/* Register the MDIO bus */
175 	rc = mdiobus_register(mdio);
176 	if (rc)
177 		return rc;
178 
179 	/* Loop over the child nodes and register a phy_device for each phy */
180 	for_each_available_child_of_node(np, child) {
181 		addr = of_mdio_parse_addr(&mdio->dev, child);
182 		if (addr < 0) {
183 			scanphys = true;
184 			continue;
185 		}
186 
187 		if (of_mdiobus_child_is_phy(child))
188 			rc = of_mdiobus_register_phy(mdio, child, addr);
189 		else
190 			rc = of_mdiobus_register_device(mdio, child, addr);
191 
192 		if (rc == -ENODEV)
193 			dev_err(&mdio->dev,
194 				"MDIO device at address %d is missing.\n",
195 				addr);
196 		else if (rc)
197 			goto unregister;
198 	}
199 
200 	if (!scanphys)
201 		return 0;
202 
203 	/* auto scan for PHYs with empty reg property */
204 	for_each_available_child_of_node(np, child) {
205 		/* Skip PHYs with reg property set */
206 		if (of_find_property(child, "reg", NULL))
207 			continue;
208 
209 		for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
210 			/* skip already registered PHYs */
211 			if (mdiobus_is_registered_device(mdio, addr))
212 				continue;
213 
214 			/* be noisy to encourage people to set reg property */
215 			dev_info(&mdio->dev, "scan phy %pOFn at address %i\n",
216 				 child, addr);
217 
218 			if (of_mdiobus_child_is_phy(child)) {
219 				/* -ENODEV is the return code that PHYLIB has
220 				 * standardized on to indicate that bus
221 				 * scanning should continue.
222 				 */
223 				rc = of_mdiobus_register_phy(mdio, child, addr);
224 				if (!rc)
225 					break;
226 				if (rc != -ENODEV)
227 					goto unregister;
228 			}
229 		}
230 	}
231 
232 	return 0;
233 
234 unregister:
235 	of_node_put(child);
236 	mdiobus_unregister(mdio);
237 	return rc;
238 }
239 EXPORT_SYMBOL(of_mdiobus_register);
240 
241 /**
242  * of_mdio_find_device - Given a device tree node, find the mdio_device
243  * @np: pointer to the mdio_device's device tree node
244  *
245  * If successful, returns a pointer to the mdio_device with the embedded
246  * struct device refcount incremented by one, or NULL on failure.
247  * The caller should call put_device() on the mdio_device after its use
248  */
249 struct mdio_device *of_mdio_find_device(struct device_node *np)
250 {
251 	return fwnode_mdio_find_device(of_fwnode_handle(np));
252 }
253 EXPORT_SYMBOL(of_mdio_find_device);
254 
255 /**
256  * of_phy_find_device - Give a PHY node, find the phy_device
257  * @phy_np: Pointer to the phy's device tree node
258  *
259  * If successful, returns a pointer to the phy_device with the embedded
260  * struct device refcount incremented by one, or NULL on failure.
261  */
262 struct phy_device *of_phy_find_device(struct device_node *phy_np)
263 {
264 	return fwnode_phy_find_device(of_fwnode_handle(phy_np));
265 }
266 EXPORT_SYMBOL(of_phy_find_device);
267 
268 /**
269  * of_phy_connect - Connect to the phy described in the device tree
270  * @dev: pointer to net_device claiming the phy
271  * @phy_np: Pointer to device tree node for the PHY
272  * @hndlr: Link state callback for the network device
273  * @flags: flags to pass to the PHY
274  * @iface: PHY data interface type
275  *
276  * If successful, returns a pointer to the phy_device with the embedded
277  * struct device refcount incremented by one, or NULL on failure. The
278  * refcount must be dropped by calling phy_disconnect() or phy_detach().
279  */
280 struct phy_device *of_phy_connect(struct net_device *dev,
281 				  struct device_node *phy_np,
282 				  void (*hndlr)(struct net_device *), u32 flags,
283 				  phy_interface_t iface)
284 {
285 	struct phy_device *phy = of_phy_find_device(phy_np);
286 	int ret;
287 
288 	if (!phy)
289 		return NULL;
290 
291 	phy->dev_flags |= flags;
292 
293 	ret = phy_connect_direct(dev, phy, hndlr, iface);
294 
295 	/* refcount is held by phy_connect_direct() on success */
296 	put_device(&phy->mdio.dev);
297 
298 	return ret ? NULL : phy;
299 }
300 EXPORT_SYMBOL(of_phy_connect);
301 
302 /**
303  * of_phy_get_and_connect
304  * - Get phy node and connect to the phy described in the device tree
305  * @dev: pointer to net_device claiming the phy
306  * @np: Pointer to device tree node for the net_device claiming the phy
307  * @hndlr: Link state callback for the network device
308  *
309  * If successful, returns a pointer to the phy_device with the embedded
310  * struct device refcount incremented by one, or NULL on failure. The
311  * refcount must be dropped by calling phy_disconnect() or phy_detach().
312  */
313 struct phy_device *of_phy_get_and_connect(struct net_device *dev,
314 					  struct device_node *np,
315 					  void (*hndlr)(struct net_device *))
316 {
317 	phy_interface_t iface;
318 	struct device_node *phy_np;
319 	struct phy_device *phy;
320 	int ret;
321 
322 	ret = of_get_phy_mode(np, &iface);
323 	if (ret)
324 		return NULL;
325 	if (of_phy_is_fixed_link(np)) {
326 		ret = of_phy_register_fixed_link(np);
327 		if (ret < 0) {
328 			netdev_err(dev, "broken fixed-link specification\n");
329 			return NULL;
330 		}
331 		phy_np = of_node_get(np);
332 	} else {
333 		phy_np = of_parse_phandle(np, "phy-handle", 0);
334 		if (!phy_np)
335 			return NULL;
336 	}
337 
338 	phy = of_phy_connect(dev, phy_np, hndlr, 0, iface);
339 
340 	of_node_put(phy_np);
341 
342 	return phy;
343 }
344 EXPORT_SYMBOL(of_phy_get_and_connect);
345 
346 /*
347  * of_phy_is_fixed_link() and of_phy_register_fixed_link() must
348  * support two DT bindings:
349  * - the old DT binding, where 'fixed-link' was a property with 5
350  *   cells encoding various information about the fixed PHY
351  * - the new DT binding, where 'fixed-link' is a sub-node of the
352  *   Ethernet device.
353  */
354 bool of_phy_is_fixed_link(struct device_node *np)
355 {
356 	struct device_node *dn;
357 	int len, err;
358 	const char *managed;
359 
360 	/* New binding */
361 	dn = of_get_child_by_name(np, "fixed-link");
362 	if (dn) {
363 		of_node_put(dn);
364 		return true;
365 	}
366 
367 	err = of_property_read_string(np, "managed", &managed);
368 	if (err == 0 && strcmp(managed, "auto") != 0)
369 		return true;
370 
371 	/* Old binding */
372 	if (of_get_property(np, "fixed-link", &len) &&
373 	    len == (5 * sizeof(__be32)))
374 		return true;
375 
376 	return false;
377 }
378 EXPORT_SYMBOL(of_phy_is_fixed_link);
379 
380 int of_phy_register_fixed_link(struct device_node *np)
381 {
382 	struct fixed_phy_status status = {};
383 	struct device_node *fixed_link_node;
384 	u32 fixed_link_prop[5];
385 	const char *managed;
386 
387 	if (of_property_read_string(np, "managed", &managed) == 0 &&
388 	    strcmp(managed, "in-band-status") == 0) {
389 		/* status is zeroed, namely its .link member */
390 		goto register_phy;
391 	}
392 
393 	/* New binding */
394 	fixed_link_node = of_get_child_by_name(np, "fixed-link");
395 	if (fixed_link_node) {
396 		status.link = 1;
397 		status.duplex = of_property_read_bool(fixed_link_node,
398 						      "full-duplex");
399 		if (of_property_read_u32(fixed_link_node, "speed",
400 					 &status.speed)) {
401 			of_node_put(fixed_link_node);
402 			return -EINVAL;
403 		}
404 		status.pause = of_property_read_bool(fixed_link_node, "pause");
405 		status.asym_pause = of_property_read_bool(fixed_link_node,
406 							  "asym-pause");
407 		of_node_put(fixed_link_node);
408 
409 		goto register_phy;
410 	}
411 
412 	/* Old binding */
413 	if (of_property_read_u32_array(np, "fixed-link", fixed_link_prop,
414 				       ARRAY_SIZE(fixed_link_prop)) == 0) {
415 		status.link = 1;
416 		status.duplex = fixed_link_prop[1];
417 		status.speed  = fixed_link_prop[2];
418 		status.pause  = fixed_link_prop[3];
419 		status.asym_pause = fixed_link_prop[4];
420 		goto register_phy;
421 	}
422 
423 	return -ENODEV;
424 
425 register_phy:
426 	return PTR_ERR_OR_ZERO(fixed_phy_register(PHY_POLL, &status, np));
427 }
428 EXPORT_SYMBOL(of_phy_register_fixed_link);
429 
430 void of_phy_deregister_fixed_link(struct device_node *np)
431 {
432 	struct phy_device *phydev;
433 
434 	phydev = of_phy_find_device(np);
435 	if (!phydev)
436 		return;
437 
438 	fixed_phy_unregister(phydev);
439 
440 	put_device(&phydev->mdio.dev);	/* of_phy_find_device() */
441 	phy_device_free(phydev);	/* fixed_phy_register() */
442 }
443 EXPORT_SYMBOL(of_phy_deregister_fixed_link);
444