xref: /linux/drivers/net/mdio/of_mdio.c (revision 6aac2aa2dfae38b60f22c3dfe4103ceefbe2d761)
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 MODULE_DESCRIPTION("OpenFirmware MDIO bus (Ethernet PHY) accessors");
29 
30 /* Extract the clause 22 phy ID from the compatible string of the form
31  * ethernet-phy-idAAAA.BBBB */
32 static int of_get_phy_id(struct device_node *device, u32 *phy_id)
33 {
34 	return fwnode_get_phy_id(of_fwnode_handle(device), phy_id);
35 }
36 
37 int of_mdiobus_phy_device_register(struct mii_bus *mdio, struct phy_device *phy,
38 				   struct device_node *child, u32 addr)
39 {
40 	return fwnode_mdiobus_phy_device_register(mdio, phy,
41 						  of_fwnode_handle(child),
42 						  addr);
43 }
44 EXPORT_SYMBOL(of_mdiobus_phy_device_register);
45 
46 static int of_mdiobus_register_phy(struct mii_bus *mdio,
47 				    struct device_node *child, u32 addr)
48 {
49 	return fwnode_mdiobus_register_phy(mdio, of_fwnode_handle(child), addr);
50 }
51 
52 static int of_mdiobus_register_device(struct mii_bus *mdio,
53 				      struct device_node *child, u32 addr)
54 {
55 	struct fwnode_handle *fwnode = of_fwnode_handle(child);
56 	struct mdio_device *mdiodev;
57 	int rc;
58 
59 	mdiodev = mdio_device_create(mdio, addr);
60 	if (IS_ERR(mdiodev))
61 		return PTR_ERR(mdiodev);
62 
63 	/* Associate the OF node with the device structure so it
64 	 * can be looked up later.
65 	 */
66 	device_set_node(&mdiodev->dev, fwnode_handle_get(fwnode));
67 
68 	/* All data is now stored in the mdiodev struct; register it. */
69 	rc = mdio_device_register(mdiodev);
70 	if (rc) {
71 		mdio_device_free(mdiodev);
72 		return rc;
73 	}
74 
75 	dev_dbg(&mdio->dev, "registered mdio device %pOFn at address %i\n",
76 		child, addr);
77 	return 0;
78 }
79 
80 /* The following is a list of PHY compatible strings which appear in
81  * some DTBs. The compatible string is never matched against a PHY
82  * driver, so is pointless. We only expect devices which are not PHYs
83  * to have a compatible string, so they can be matched to an MDIO
84  * driver.  Encourage users to upgrade their DT blobs to remove these.
85  */
86 static const struct of_device_id whitelist_phys[] = {
87 	{ .compatible = "brcm,40nm-ephy" },
88 	{ .compatible = "broadcom,bcm5241" },
89 	{ .compatible = "marvell,88E1111", },
90 	{ .compatible = "marvell,88e1116", },
91 	{ .compatible = "marvell,88e1118", },
92 	{ .compatible = "marvell,88e1145", },
93 	{ .compatible = "marvell,88e1149r", },
94 	{ .compatible = "marvell,88e1310", },
95 	{ .compatible = "marvell,88E1510", },
96 	{ .compatible = "marvell,88E1514", },
97 	{ .compatible = "moxa,moxart-rtl8201cp", },
98 	{}
99 };
100 
101 /*
102  * Return true if the child node is for a phy. It must either:
103  * o Compatible string of "ethernet-phy-idX.X"
104  * o Compatible string of "ethernet-phy-ieee802.3-c45"
105  * o Compatible string of "ethernet-phy-ieee802.3-c22"
106  * o In the white list above (and issue a warning)
107  * o No compatibility string
108  *
109  * A device which is not a phy is expected to have a compatible string
110  * indicating what sort of device it is.
111  */
112 bool of_mdiobus_child_is_phy(struct device_node *child)
113 {
114 	u32 phy_id;
115 
116 	if (of_get_phy_id(child, &phy_id) != -EINVAL)
117 		return true;
118 
119 	if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c45"))
120 		return true;
121 
122 	if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c22"))
123 		return true;
124 
125 	if (of_match_node(whitelist_phys, child)) {
126 		pr_warn(FW_WARN
127 			"%pOF: Whitelisted compatible string. Please remove\n",
128 			child);
129 		return true;
130 	}
131 
132 	if (!of_property_present(child, "compatible"))
133 		return true;
134 
135 	return false;
136 }
137 EXPORT_SYMBOL(of_mdiobus_child_is_phy);
138 
139 static int __of_mdiobus_parse_phys(struct mii_bus *mdio, struct device_node *np,
140 				   bool *scanphys)
141 {
142 	struct device_node *child;
143 	int addr, rc = 0;
144 
145 	/* Loop over the child nodes and register a phy_device for each phy */
146 	for_each_available_child_of_node(np, child) {
147 		if (of_node_name_eq(child, "ethernet-phy-package")) {
148 			/* Ignore invalid ethernet-phy-package node */
149 			if (!of_property_present(child, "reg"))
150 				continue;
151 
152 			rc = __of_mdiobus_parse_phys(mdio, child, NULL);
153 			if (rc && rc != -ENODEV)
154 				goto exit;
155 
156 			continue;
157 		}
158 
159 		addr = of_mdio_parse_addr(&mdio->dev, child);
160 		if (addr < 0) {
161 			/* Skip scanning for invalid ethernet-phy-package node */
162 			if (scanphys)
163 				*scanphys = true;
164 			continue;
165 		}
166 
167 		if (of_mdiobus_child_is_phy(child))
168 			rc = of_mdiobus_register_phy(mdio, child, addr);
169 		else
170 			rc = of_mdiobus_register_device(mdio, child, addr);
171 
172 		if (rc == -ENODEV)
173 			dev_err(&mdio->dev,
174 				"MDIO device at address %d is missing.\n",
175 				addr);
176 		else if (rc)
177 			goto exit;
178 	}
179 
180 	return 0;
181 exit:
182 	of_node_put(child);
183 	return rc;
184 }
185 
186 /**
187  * __of_mdiobus_register - Register mii_bus and create PHYs from the device tree
188  * @mdio: pointer to mii_bus structure
189  * @np: pointer to device_node of MDIO bus.
190  * @owner: module owning the @mdio object.
191  *
192  * This function registers the mii_bus structure and registers a phy_device
193  * for each child node of @np.
194  */
195 int __of_mdiobus_register(struct mii_bus *mdio, struct device_node *np,
196 			  struct module *owner)
197 {
198 	struct device_node *child;
199 	bool scanphys = false;
200 	int addr, rc;
201 
202 	if (!np)
203 		return __mdiobus_register(mdio, owner);
204 
205 	/* Do not continue if the node is disabled */
206 	if (!of_device_is_available(np))
207 		return -ENODEV;
208 
209 	/* Mask out all PHYs from auto probing.  Instead the PHYs listed in
210 	 * the device tree are populated after the bus has been registered */
211 	mdio->phy_mask = ~0;
212 
213 	device_set_node(&mdio->dev, of_fwnode_handle(np));
214 
215 	/* Get bus level PHY reset GPIO details */
216 	mdio->reset_delay_us = DEFAULT_GPIO_RESET_DELAY;
217 	of_property_read_u32(np, "reset-delay-us", &mdio->reset_delay_us);
218 	mdio->reset_post_delay_us = 0;
219 	of_property_read_u32(np, "reset-post-delay-us", &mdio->reset_post_delay_us);
220 
221 	/* Register the MDIO bus */
222 	rc = __mdiobus_register(mdio, owner);
223 	if (rc)
224 		return rc;
225 
226 	/* Loop over the child nodes and register a phy_device for each phy */
227 	rc = __of_mdiobus_parse_phys(mdio, np, &scanphys);
228 	if (rc)
229 		goto unregister;
230 
231 	if (!scanphys)
232 		return 0;
233 
234 	/* auto scan for PHYs with empty reg property */
235 	for_each_available_child_of_node(np, child) {
236 		/* Skip PHYs with reg property set or ethernet-phy-package node */
237 		if (of_property_present(child, "reg") ||
238 		    of_node_name_eq(child, "ethernet-phy-package"))
239 			continue;
240 
241 		for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
242 			/* skip already registered PHYs */
243 			if (mdiobus_is_registered_device(mdio, addr))
244 				continue;
245 
246 			/* be noisy to encourage people to set reg property */
247 			dev_info(&mdio->dev, "scan phy %pOFn at address %i\n",
248 				 child, addr);
249 
250 			if (of_mdiobus_child_is_phy(child)) {
251 				/* -ENODEV is the return code that PHYLIB has
252 				 * standardized on to indicate that bus
253 				 * scanning should continue.
254 				 */
255 				rc = of_mdiobus_register_phy(mdio, child, addr);
256 				if (!rc)
257 					break;
258 				if (rc != -ENODEV)
259 					goto put_unregister;
260 			}
261 		}
262 	}
263 
264 	return 0;
265 
266 put_unregister:
267 	of_node_put(child);
268 unregister:
269 	mdiobus_unregister(mdio);
270 	return rc;
271 }
272 EXPORT_SYMBOL(__of_mdiobus_register);
273 
274 /**
275  * of_mdio_find_device - Given a device tree node, find the mdio_device
276  * @np: pointer to the mdio_device's device tree node
277  *
278  * If successful, returns a pointer to the mdio_device with the embedded
279  * struct device refcount incremented by one, or NULL on failure.
280  * The caller should call put_device() on the mdio_device after its use
281  */
282 struct mdio_device *of_mdio_find_device(struct device_node *np)
283 {
284 	return fwnode_mdio_find_device(of_fwnode_handle(np));
285 }
286 EXPORT_SYMBOL(of_mdio_find_device);
287 
288 /**
289  * of_phy_find_device - Give a PHY node, find the phy_device
290  * @phy_np: Pointer to the phy's device tree node
291  *
292  * If successful, returns a pointer to the phy_device with the embedded
293  * struct device refcount incremented by one, or NULL on failure.
294  */
295 struct phy_device *of_phy_find_device(struct device_node *phy_np)
296 {
297 	return fwnode_phy_find_device(of_fwnode_handle(phy_np));
298 }
299 EXPORT_SYMBOL(of_phy_find_device);
300 
301 /**
302  * of_phy_connect - Connect to the phy described in the device tree
303  * @dev: pointer to net_device claiming the phy
304  * @phy_np: Pointer to device tree node for the PHY
305  * @hndlr: Link state callback for the network device
306  * @flags: flags to pass to the PHY
307  * @iface: PHY data interface type
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_connect(struct net_device *dev,
314 				  struct device_node *phy_np,
315 				  void (*hndlr)(struct net_device *), u32 flags,
316 				  phy_interface_t iface)
317 {
318 	struct phy_device *phy = of_phy_find_device(phy_np);
319 	int ret;
320 
321 	if (!phy)
322 		return NULL;
323 
324 	phy->dev_flags |= flags;
325 
326 	ret = phy_connect_direct(dev, phy, hndlr, iface);
327 
328 	/* refcount is held by phy_connect_direct() on success */
329 	put_device(&phy->mdio.dev);
330 
331 	return ret ? NULL : phy;
332 }
333 EXPORT_SYMBOL(of_phy_connect);
334 
335 /**
336  * of_phy_get_and_connect
337  * - Get phy node and connect to the phy described in the device tree
338  * @dev: pointer to net_device claiming the phy
339  * @np: Pointer to device tree node for the net_device claiming the phy
340  * @hndlr: Link state callback for the network device
341  *
342  * If successful, returns a pointer to the phy_device with the embedded
343  * struct device refcount incremented by one, or NULL on failure. The
344  * refcount must be dropped by calling phy_disconnect() or phy_detach().
345  */
346 struct phy_device *of_phy_get_and_connect(struct net_device *dev,
347 					  struct device_node *np,
348 					  void (*hndlr)(struct net_device *))
349 {
350 	phy_interface_t iface;
351 	struct device_node *phy_np;
352 	struct phy_device *phy;
353 	int ret;
354 
355 	ret = of_get_phy_mode(np, &iface);
356 	if (ret)
357 		return NULL;
358 	if (of_phy_is_fixed_link(np)) {
359 		ret = of_phy_register_fixed_link(np);
360 		if (ret < 0) {
361 			netdev_err(dev, "broken fixed-link specification\n");
362 			return NULL;
363 		}
364 		phy_np = of_node_get(np);
365 	} else {
366 		phy_np = of_parse_phandle(np, "phy-handle", 0);
367 		if (!phy_np)
368 			return NULL;
369 	}
370 
371 	phy = of_phy_connect(dev, phy_np, hndlr, 0, iface);
372 
373 	of_node_put(phy_np);
374 
375 	return phy;
376 }
377 EXPORT_SYMBOL(of_phy_get_and_connect);
378 
379 /*
380  * of_phy_is_fixed_link() and of_phy_register_fixed_link() must
381  * support two DT bindings:
382  * - the old DT binding, where 'fixed-link' was a property with 5
383  *   cells encoding various information about the fixed PHY
384  * - the new DT binding, where 'fixed-link' is a sub-node of the
385  *   Ethernet device.
386  */
387 bool of_phy_is_fixed_link(struct device_node *np)
388 {
389 	struct device_node *dn;
390 	int err;
391 	const char *managed;
392 
393 	/* New binding */
394 	dn = of_get_child_by_name(np, "fixed-link");
395 	if (dn) {
396 		of_node_put(dn);
397 		return true;
398 	}
399 
400 	err = of_property_read_string(np, "managed", &managed);
401 	if (err == 0 && strcmp(managed, "auto") != 0)
402 		return true;
403 
404 	/* Old binding */
405 	if (of_property_count_u32_elems(np, "fixed-link") == 5)
406 		return true;
407 
408 	return false;
409 }
410 EXPORT_SYMBOL(of_phy_is_fixed_link);
411 
412 int of_phy_register_fixed_link(struct device_node *np)
413 {
414 	struct fixed_phy_status status = {};
415 	struct device_node *fixed_link_node;
416 	u32 fixed_link_prop[5];
417 	const char *managed;
418 
419 	if (of_property_read_string(np, "managed", &managed) == 0 &&
420 	    strcmp(managed, "in-band-status") == 0) {
421 		/* status is zeroed, namely its .link member */
422 		goto register_phy;
423 	}
424 
425 	/* New binding */
426 	fixed_link_node = of_get_child_by_name(np, "fixed-link");
427 	if (fixed_link_node) {
428 		status.link = 1;
429 		status.duplex = of_property_read_bool(fixed_link_node,
430 						      "full-duplex");
431 		if (of_property_read_u32(fixed_link_node, "speed",
432 					 &status.speed)) {
433 			of_node_put(fixed_link_node);
434 			return -EINVAL;
435 		}
436 		status.pause = of_property_read_bool(fixed_link_node, "pause");
437 		status.asym_pause = of_property_read_bool(fixed_link_node,
438 							  "asym-pause");
439 		of_node_put(fixed_link_node);
440 
441 		goto register_phy;
442 	}
443 
444 	/* Old binding */
445 	if (of_property_read_u32_array(np, "fixed-link", fixed_link_prop,
446 				       ARRAY_SIZE(fixed_link_prop)) == 0) {
447 		pr_warn_once("%pOF uses deprecated array-style fixed-link binding!\n",
448 			     np);
449 		status.link = 1;
450 		status.duplex = fixed_link_prop[1];
451 		status.speed  = fixed_link_prop[2];
452 		status.pause  = fixed_link_prop[3];
453 		status.asym_pause = fixed_link_prop[4];
454 		goto register_phy;
455 	}
456 
457 	return -ENODEV;
458 
459 register_phy:
460 	return PTR_ERR_OR_ZERO(fixed_phy_register(&status, np));
461 }
462 EXPORT_SYMBOL(of_phy_register_fixed_link);
463 
464 void of_phy_deregister_fixed_link(struct device_node *np)
465 {
466 	struct phy_device *phydev;
467 
468 	phydev = of_phy_find_device(np);
469 	if (!phydev)
470 		return;
471 
472 	fixed_phy_unregister(phydev);
473 
474 	put_device(&phydev->mdio.dev);	/* of_phy_find_device() */
475 }
476 EXPORT_SYMBOL(of_phy_deregister_fixed_link);
477