xref: /openbmc/linux/drivers/net/mdio/of_mdio.c (revision b737eecd)
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/kernel.h>
12 #include <linux/device.h>
13 #include <linux/netdevice.h>
14 #include <linux/err.h>
15 #include <linux/phy.h>
16 #include <linux/phy_fixed.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/module.h>
22 
23 #define DEFAULT_GPIO_RESET_DELAY	10	/* in microseconds */
24 
25 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
26 MODULE_LICENSE("GPL");
27 
28 /* Extract the clause 22 phy ID from the compatible string of the form
29  * ethernet-phy-idAAAA.BBBB */
30 static int of_get_phy_id(struct device_node *device, u32 *phy_id)
31 {
32 	struct property *prop;
33 	const char *cp;
34 	unsigned int upper, lower;
35 
36 	of_property_for_each_string(device, "compatible", prop, cp) {
37 		if (sscanf(cp, "ethernet-phy-id%4x.%4x", &upper, &lower) == 2) {
38 			*phy_id = ((upper & 0xFFFF) << 16) | (lower & 0xFFFF);
39 			return 0;
40 		}
41 	}
42 	return -EINVAL;
43 }
44 
45 static struct mii_timestamper *of_find_mii_timestamper(struct device_node *node)
46 {
47 	struct of_phandle_args arg;
48 	int err;
49 
50 	err = of_parse_phandle_with_fixed_args(node, "timestamper", 1, 0, &arg);
51 
52 	if (err == -ENOENT)
53 		return NULL;
54 	else if (err)
55 		return ERR_PTR(err);
56 
57 	if (arg.args_count != 1)
58 		return ERR_PTR(-EINVAL);
59 
60 	return register_mii_timestamper(arg.np, arg.args[0]);
61 }
62 
63 int of_mdiobus_phy_device_register(struct mii_bus *mdio, struct phy_device *phy,
64 			      struct device_node *child, u32 addr)
65 {
66 	int rc;
67 
68 	rc = of_irq_get(child, 0);
69 	if (rc == -EPROBE_DEFER)
70 		return rc;
71 
72 	if (rc > 0) {
73 		phy->irq = rc;
74 		mdio->irq[addr] = rc;
75 	} else {
76 		phy->irq = mdio->irq[addr];
77 	}
78 
79 	if (of_property_read_bool(child, "broken-turn-around"))
80 		mdio->phy_ignore_ta_mask |= 1 << addr;
81 
82 	of_property_read_u32(child, "reset-assert-us",
83 			     &phy->mdio.reset_assert_delay);
84 	of_property_read_u32(child, "reset-deassert-us",
85 			     &phy->mdio.reset_deassert_delay);
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->mdio.dev.of_node = child;
91 	phy->mdio.dev.fwnode = of_fwnode_handle(child);
92 
93 	/* All data is now stored in the phy struct;
94 	 * register it */
95 	rc = phy_device_register(phy);
96 	if (rc) {
97 		of_node_put(child);
98 		return rc;
99 	}
100 
101 	dev_dbg(&mdio->dev, "registered phy %pOFn at address %i\n",
102 		child, addr);
103 	return 0;
104 }
105 EXPORT_SYMBOL(of_mdiobus_phy_device_register);
106 
107 static int of_mdiobus_register_phy(struct mii_bus *mdio,
108 				    struct device_node *child, u32 addr)
109 {
110 	struct mii_timestamper *mii_ts;
111 	struct phy_device *phy;
112 	bool is_c45;
113 	int rc;
114 	u32 phy_id;
115 
116 	mii_ts = of_find_mii_timestamper(child);
117 	if (IS_ERR(mii_ts))
118 		return PTR_ERR(mii_ts);
119 
120 	is_c45 = of_device_is_compatible(child,
121 					 "ethernet-phy-ieee802.3-c45");
122 
123 	if (!is_c45 && !of_get_phy_id(child, &phy_id))
124 		phy = phy_device_create(mdio, addr, phy_id, 0, NULL);
125 	else
126 		phy = get_phy_device(mdio, addr, is_c45);
127 	if (IS_ERR(phy)) {
128 		if (mii_ts)
129 			unregister_mii_timestamper(mii_ts);
130 		return PTR_ERR(phy);
131 	}
132 
133 	rc = of_mdiobus_phy_device_register(mdio, phy, child, addr);
134 	if (rc) {
135 		if (mii_ts)
136 			unregister_mii_timestamper(mii_ts);
137 		phy_device_free(phy);
138 		return rc;
139 	}
140 
141 	/* phy->mii_ts may already be defined by the PHY driver. A
142 	 * mii_timestamper probed via the device tree will still have
143 	 * precedence.
144 	 */
145 	if (mii_ts)
146 		phy->mii_ts = mii_ts;
147 
148 	return 0;
149 }
150 
151 static int of_mdiobus_register_device(struct mii_bus *mdio,
152 				      struct device_node *child, u32 addr)
153 {
154 	struct mdio_device *mdiodev;
155 	int rc;
156 
157 	mdiodev = mdio_device_create(mdio, addr);
158 	if (IS_ERR(mdiodev))
159 		return PTR_ERR(mdiodev);
160 
161 	/* Associate the OF node with the device structure so it
162 	 * can be looked up later.
163 	 */
164 	of_node_get(child);
165 	mdiodev->dev.of_node = child;
166 	mdiodev->dev.fwnode = of_fwnode_handle(child);
167 
168 	/* All data is now stored in the mdiodev struct; register it. */
169 	rc = mdio_device_register(mdiodev);
170 	if (rc) {
171 		mdio_device_free(mdiodev);
172 		of_node_put(child);
173 		return rc;
174 	}
175 
176 	dev_dbg(&mdio->dev, "registered mdio device %pOFn at address %i\n",
177 		child, addr);
178 	return 0;
179 }
180 
181 /* The following is a list of PHY compatible strings which appear in
182  * some DTBs. The compatible string is never matched against a PHY
183  * driver, so is pointless. We only expect devices which are not PHYs
184  * to have a compatible string, so they can be matched to an MDIO
185  * driver.  Encourage users to upgrade their DT blobs to remove these.
186  */
187 static const struct of_device_id whitelist_phys[] = {
188 	{ .compatible = "brcm,40nm-ephy" },
189 	{ .compatible = "broadcom,bcm5241" },
190 	{ .compatible = "marvell,88E1111", },
191 	{ .compatible = "marvell,88e1116", },
192 	{ .compatible = "marvell,88e1118", },
193 	{ .compatible = "marvell,88e1145", },
194 	{ .compatible = "marvell,88e1149r", },
195 	{ .compatible = "marvell,88e1310", },
196 	{ .compatible = "marvell,88E1510", },
197 	{ .compatible = "marvell,88E1514", },
198 	{ .compatible = "moxa,moxart-rtl8201cp", },
199 	{}
200 };
201 
202 /*
203  * Return true if the child node is for a phy. It must either:
204  * o Compatible string of "ethernet-phy-idX.X"
205  * o Compatible string of "ethernet-phy-ieee802.3-c45"
206  * o Compatible string of "ethernet-phy-ieee802.3-c22"
207  * o In the white list above (and issue a warning)
208  * o No compatibility string
209  *
210  * A device which is not a phy is expected to have a compatible string
211  * indicating what sort of device it is.
212  */
213 bool of_mdiobus_child_is_phy(struct device_node *child)
214 {
215 	u32 phy_id;
216 
217 	if (of_get_phy_id(child, &phy_id) != -EINVAL)
218 		return true;
219 
220 	if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c45"))
221 		return true;
222 
223 	if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c22"))
224 		return true;
225 
226 	if (of_match_node(whitelist_phys, child)) {
227 		pr_warn(FW_WARN
228 			"%pOF: Whitelisted compatible string. Please remove\n",
229 			child);
230 		return true;
231 	}
232 
233 	if (!of_find_property(child, "compatible", NULL))
234 		return true;
235 
236 	return false;
237 }
238 EXPORT_SYMBOL(of_mdiobus_child_is_phy);
239 
240 /**
241  * of_mdiobus_register - Register mii_bus and create PHYs from the device tree
242  * @mdio: pointer to mii_bus structure
243  * @np: pointer to device_node of MDIO bus.
244  *
245  * This function registers the mii_bus structure and registers a phy_device
246  * for each child node of @np.
247  */
248 int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
249 {
250 	struct device_node *child;
251 	bool scanphys = false;
252 	int addr, rc;
253 
254 	if (!np)
255 		return mdiobus_register(mdio);
256 
257 	/* Do not continue if the node is disabled */
258 	if (!of_device_is_available(np))
259 		return -ENODEV;
260 
261 	/* Mask out all PHYs from auto probing.  Instead the PHYs listed in
262 	 * the device tree are populated after the bus has been registered */
263 	mdio->phy_mask = ~0;
264 
265 	mdio->dev.of_node = np;
266 	mdio->dev.fwnode = of_fwnode_handle(np);
267 
268 	/* Get bus level PHY reset GPIO details */
269 	mdio->reset_delay_us = DEFAULT_GPIO_RESET_DELAY;
270 	of_property_read_u32(np, "reset-delay-us", &mdio->reset_delay_us);
271 	mdio->reset_post_delay_us = 0;
272 	of_property_read_u32(np, "reset-post-delay-us", &mdio->reset_post_delay_us);
273 
274 	/* Register the MDIO bus */
275 	rc = mdiobus_register(mdio);
276 	if (rc)
277 		return rc;
278 
279 	/* Loop over the child nodes and register a phy_device for each phy */
280 	for_each_available_child_of_node(np, child) {
281 		addr = of_mdio_parse_addr(&mdio->dev, child);
282 		if (addr < 0) {
283 			scanphys = true;
284 			continue;
285 		}
286 
287 		if (of_mdiobus_child_is_phy(child))
288 			rc = of_mdiobus_register_phy(mdio, child, addr);
289 		else
290 			rc = of_mdiobus_register_device(mdio, child, addr);
291 
292 		if (rc == -ENODEV)
293 			dev_err(&mdio->dev,
294 				"MDIO device at address %d is missing.\n",
295 				addr);
296 		else if (rc)
297 			goto unregister;
298 	}
299 
300 	if (!scanphys)
301 		return 0;
302 
303 	/* auto scan for PHYs with empty reg property */
304 	for_each_available_child_of_node(np, child) {
305 		/* Skip PHYs with reg property set */
306 		if (of_find_property(child, "reg", NULL))
307 			continue;
308 
309 		for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
310 			/* skip already registered PHYs */
311 			if (mdiobus_is_registered_device(mdio, addr))
312 				continue;
313 
314 			/* be noisy to encourage people to set reg property */
315 			dev_info(&mdio->dev, "scan phy %pOFn at address %i\n",
316 				 child, addr);
317 
318 			if (of_mdiobus_child_is_phy(child)) {
319 				/* -ENODEV is the return code that PHYLIB has
320 				 * standardized on to indicate that bus
321 				 * scanning should continue.
322 				 */
323 				rc = of_mdiobus_register_phy(mdio, child, addr);
324 				if (!rc)
325 					break;
326 				if (rc != -ENODEV)
327 					goto unregister;
328 			}
329 		}
330 	}
331 
332 	return 0;
333 
334 unregister:
335 	mdiobus_unregister(mdio);
336 	return rc;
337 }
338 EXPORT_SYMBOL(of_mdiobus_register);
339 
340 /**
341  * of_mdio_find_device - Given a device tree node, find the mdio_device
342  * @np: pointer to the mdio_device's device tree node
343  *
344  * If successful, returns a pointer to the mdio_device with the embedded
345  * struct device refcount incremented by one, or NULL on failure.
346  * The caller should call put_device() on the mdio_device after its use
347  */
348 struct mdio_device *of_mdio_find_device(struct device_node *np)
349 {
350 	struct device *d;
351 
352 	if (!np)
353 		return NULL;
354 
355 	d = bus_find_device_by_of_node(&mdio_bus_type, np);
356 	if (!d)
357 		return NULL;
358 
359 	return to_mdio_device(d);
360 }
361 EXPORT_SYMBOL(of_mdio_find_device);
362 
363 /**
364  * of_phy_find_device - Give a PHY node, find the phy_device
365  * @phy_np: Pointer to the phy's device tree node
366  *
367  * If successful, returns a pointer to the phy_device with the embedded
368  * struct device refcount incremented by one, or NULL on failure.
369  */
370 struct phy_device *of_phy_find_device(struct device_node *phy_np)
371 {
372 	struct mdio_device *mdiodev;
373 
374 	mdiodev = of_mdio_find_device(phy_np);
375 	if (!mdiodev)
376 		return NULL;
377 
378 	if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY)
379 		return to_phy_device(&mdiodev->dev);
380 
381 	put_device(&mdiodev->dev);
382 
383 	return NULL;
384 }
385 EXPORT_SYMBOL(of_phy_find_device);
386 
387 /**
388  * of_phy_connect - Connect to the phy described in the device tree
389  * @dev: pointer to net_device claiming the phy
390  * @phy_np: Pointer to device tree node for the PHY
391  * @hndlr: Link state callback for the network device
392  * @flags: flags to pass to the PHY
393  * @iface: PHY data interface type
394  *
395  * If successful, returns a pointer to the phy_device with the embedded
396  * struct device refcount incremented by one, or NULL on failure. The
397  * refcount must be dropped by calling phy_disconnect() or phy_detach().
398  */
399 struct phy_device *of_phy_connect(struct net_device *dev,
400 				  struct device_node *phy_np,
401 				  void (*hndlr)(struct net_device *), u32 flags,
402 				  phy_interface_t iface)
403 {
404 	struct phy_device *phy = of_phy_find_device(phy_np);
405 	int ret;
406 
407 	if (!phy)
408 		return NULL;
409 
410 	phy->dev_flags |= flags;
411 
412 	ret = phy_connect_direct(dev, phy, hndlr, iface);
413 
414 	/* refcount is held by phy_connect_direct() on success */
415 	put_device(&phy->mdio.dev);
416 
417 	return ret ? NULL : phy;
418 }
419 EXPORT_SYMBOL(of_phy_connect);
420 
421 /**
422  * of_phy_get_and_connect
423  * - Get phy node and connect to the phy described in the device tree
424  * @dev: pointer to net_device claiming the phy
425  * @np: Pointer to device tree node for the net_device claiming the phy
426  * @hndlr: Link state callback for the network device
427  *
428  * If successful, returns a pointer to the phy_device with the embedded
429  * struct device refcount incremented by one, or NULL on failure. The
430  * refcount must be dropped by calling phy_disconnect() or phy_detach().
431  */
432 struct phy_device *of_phy_get_and_connect(struct net_device *dev,
433 					  struct device_node *np,
434 					  void (*hndlr)(struct net_device *))
435 {
436 	phy_interface_t iface;
437 	struct device_node *phy_np;
438 	struct phy_device *phy;
439 	int ret;
440 
441 	ret = of_get_phy_mode(np, &iface);
442 	if (ret)
443 		return NULL;
444 	if (of_phy_is_fixed_link(np)) {
445 		ret = of_phy_register_fixed_link(np);
446 		if (ret < 0) {
447 			netdev_err(dev, "broken fixed-link specification\n");
448 			return NULL;
449 		}
450 		phy_np = of_node_get(np);
451 	} else {
452 		phy_np = of_parse_phandle(np, "phy-handle", 0);
453 		if (!phy_np)
454 			return NULL;
455 	}
456 
457 	phy = of_phy_connect(dev, phy_np, hndlr, 0, iface);
458 
459 	of_node_put(phy_np);
460 
461 	return phy;
462 }
463 EXPORT_SYMBOL(of_phy_get_and_connect);
464 
465 /*
466  * of_phy_is_fixed_link() and of_phy_register_fixed_link() must
467  * support two DT bindings:
468  * - the old DT binding, where 'fixed-link' was a property with 5
469  *   cells encoding various informations about the fixed PHY
470  * - the new DT binding, where 'fixed-link' is a sub-node of the
471  *   Ethernet device.
472  */
473 bool of_phy_is_fixed_link(struct device_node *np)
474 {
475 	struct device_node *dn;
476 	int len, err;
477 	const char *managed;
478 
479 	/* New binding */
480 	dn = of_get_child_by_name(np, "fixed-link");
481 	if (dn) {
482 		of_node_put(dn);
483 		return true;
484 	}
485 
486 	err = of_property_read_string(np, "managed", &managed);
487 	if (err == 0 && strcmp(managed, "auto") != 0)
488 		return true;
489 
490 	/* Old binding */
491 	if (of_get_property(np, "fixed-link", &len) &&
492 	    len == (5 * sizeof(__be32)))
493 		return true;
494 
495 	return false;
496 }
497 EXPORT_SYMBOL(of_phy_is_fixed_link);
498 
499 int of_phy_register_fixed_link(struct device_node *np)
500 {
501 	struct fixed_phy_status status = {};
502 	struct device_node *fixed_link_node;
503 	u32 fixed_link_prop[5];
504 	const char *managed;
505 
506 	if (of_property_read_string(np, "managed", &managed) == 0 &&
507 	    strcmp(managed, "in-band-status") == 0) {
508 		/* status is zeroed, namely its .link member */
509 		goto register_phy;
510 	}
511 
512 	/* New binding */
513 	fixed_link_node = of_get_child_by_name(np, "fixed-link");
514 	if (fixed_link_node) {
515 		status.link = 1;
516 		status.duplex = of_property_read_bool(fixed_link_node,
517 						      "full-duplex");
518 		if (of_property_read_u32(fixed_link_node, "speed",
519 					 &status.speed)) {
520 			of_node_put(fixed_link_node);
521 			return -EINVAL;
522 		}
523 		status.pause = of_property_read_bool(fixed_link_node, "pause");
524 		status.asym_pause = of_property_read_bool(fixed_link_node,
525 							  "asym-pause");
526 		of_node_put(fixed_link_node);
527 
528 		goto register_phy;
529 	}
530 
531 	/* Old binding */
532 	if (of_property_read_u32_array(np, "fixed-link", fixed_link_prop,
533 				       ARRAY_SIZE(fixed_link_prop)) == 0) {
534 		status.link = 1;
535 		status.duplex = fixed_link_prop[1];
536 		status.speed  = fixed_link_prop[2];
537 		status.pause  = fixed_link_prop[3];
538 		status.asym_pause = fixed_link_prop[4];
539 		goto register_phy;
540 	}
541 
542 	return -ENODEV;
543 
544 register_phy:
545 	return PTR_ERR_OR_ZERO(fixed_phy_register(PHY_POLL, &status, np));
546 }
547 EXPORT_SYMBOL(of_phy_register_fixed_link);
548 
549 void of_phy_deregister_fixed_link(struct device_node *np)
550 {
551 	struct phy_device *phydev;
552 
553 	phydev = of_phy_find_device(np);
554 	if (!phydev)
555 		return;
556 
557 	fixed_phy_unregister(phydev);
558 
559 	put_device(&phydev->mdio.dev);	/* of_phy_find_device() */
560 	phy_device_free(phydev);	/* fixed_phy_register() */
561 }
562 EXPORT_SYMBOL(of_phy_deregister_fixed_link);
563