xref: /linux/drivers/net/mdio/of_mdio.c (revision 4b660dbd9ee2059850fd30e0df420ca7a38a1856)
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 	fwnode_handle_get(fwnode);
67 	device_set_node(&mdiodev->dev, fwnode);
68 
69 	/* All data is now stored in the mdiodev struct; register it. */
70 	rc = mdio_device_register(mdiodev);
71 	if (rc) {
72 		device_set_node(&mdiodev->dev, NULL);
73 		fwnode_handle_put(fwnode);
74 		mdio_device_free(mdiodev);
75 		return rc;
76 	}
77 
78 	dev_dbg(&mdio->dev, "registered mdio device %pOFn at address %i\n",
79 		child, addr);
80 	return 0;
81 }
82 
83 /* The following is a list of PHY compatible strings which appear in
84  * some DTBs. The compatible string is never matched against a PHY
85  * driver, so is pointless. We only expect devices which are not PHYs
86  * to have a compatible string, so they can be matched to an MDIO
87  * driver.  Encourage users to upgrade their DT blobs to remove these.
88  */
89 static const struct of_device_id whitelist_phys[] = {
90 	{ .compatible = "brcm,40nm-ephy" },
91 	{ .compatible = "broadcom,bcm5241" },
92 	{ .compatible = "marvell,88E1111", },
93 	{ .compatible = "marvell,88e1116", },
94 	{ .compatible = "marvell,88e1118", },
95 	{ .compatible = "marvell,88e1145", },
96 	{ .compatible = "marvell,88e1149r", },
97 	{ .compatible = "marvell,88e1310", },
98 	{ .compatible = "marvell,88E1510", },
99 	{ .compatible = "marvell,88E1514", },
100 	{ .compatible = "moxa,moxart-rtl8201cp", },
101 	{}
102 };
103 
104 /*
105  * Return true if the child node is for a phy. It must either:
106  * o Compatible string of "ethernet-phy-idX.X"
107  * o Compatible string of "ethernet-phy-ieee802.3-c45"
108  * o Compatible string of "ethernet-phy-ieee802.3-c22"
109  * o In the white list above (and issue a warning)
110  * o No compatibility string
111  *
112  * A device which is not a phy is expected to have a compatible string
113  * indicating what sort of device it is.
114  */
115 bool of_mdiobus_child_is_phy(struct device_node *child)
116 {
117 	u32 phy_id;
118 
119 	if (of_get_phy_id(child, &phy_id) != -EINVAL)
120 		return true;
121 
122 	if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c45"))
123 		return true;
124 
125 	if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c22"))
126 		return true;
127 
128 	if (of_match_node(whitelist_phys, child)) {
129 		pr_warn(FW_WARN
130 			"%pOF: Whitelisted compatible string. Please remove\n",
131 			child);
132 		return true;
133 	}
134 
135 	if (!of_property_present(child, "compatible"))
136 		return true;
137 
138 	return false;
139 }
140 EXPORT_SYMBOL(of_mdiobus_child_is_phy);
141 
142 static int __of_mdiobus_parse_phys(struct mii_bus *mdio, struct device_node *np,
143 				   bool *scanphys)
144 {
145 	struct device_node *child;
146 	int addr, rc = 0;
147 
148 	/* Loop over the child nodes and register a phy_device for each phy */
149 	for_each_available_child_of_node(np, child) {
150 		if (of_node_name_eq(child, "ethernet-phy-package")) {
151 			/* Ignore invalid ethernet-phy-package node */
152 			if (!of_property_present(child, "reg"))
153 				continue;
154 
155 			rc = __of_mdiobus_parse_phys(mdio, child, NULL);
156 			if (rc && rc != -ENODEV)
157 				goto exit;
158 
159 			continue;
160 		}
161 
162 		addr = of_mdio_parse_addr(&mdio->dev, child);
163 		if (addr < 0) {
164 			/* Skip scanning for invalid ethernet-phy-package node */
165 			if (scanphys)
166 				*scanphys = true;
167 			continue;
168 		}
169 
170 		if (of_mdiobus_child_is_phy(child))
171 			rc = of_mdiobus_register_phy(mdio, child, addr);
172 		else
173 			rc = of_mdiobus_register_device(mdio, child, addr);
174 
175 		if (rc == -ENODEV)
176 			dev_err(&mdio->dev,
177 				"MDIO device at address %d is missing.\n",
178 				addr);
179 		else if (rc)
180 			goto exit;
181 	}
182 
183 	return 0;
184 exit:
185 	of_node_put(child);
186 	return rc;
187 }
188 
189 /**
190  * __of_mdiobus_register - Register mii_bus and create PHYs from the device tree
191  * @mdio: pointer to mii_bus structure
192  * @np: pointer to device_node of MDIO bus.
193  * @owner: module owning the @mdio object.
194  *
195  * This function registers the mii_bus structure and registers a phy_device
196  * for each child node of @np.
197  */
198 int __of_mdiobus_register(struct mii_bus *mdio, struct device_node *np,
199 			  struct module *owner)
200 {
201 	struct device_node *child;
202 	bool scanphys = false;
203 	int addr, rc;
204 
205 	if (!np)
206 		return __mdiobus_register(mdio, owner);
207 
208 	/* Do not continue if the node is disabled */
209 	if (!of_device_is_available(np))
210 		return -ENODEV;
211 
212 	/* Mask out all PHYs from auto probing.  Instead the PHYs listed in
213 	 * the device tree are populated after the bus has been registered */
214 	mdio->phy_mask = ~0;
215 
216 	device_set_node(&mdio->dev, of_fwnode_handle(np));
217 
218 	/* Get bus level PHY reset GPIO details */
219 	mdio->reset_delay_us = DEFAULT_GPIO_RESET_DELAY;
220 	of_property_read_u32(np, "reset-delay-us", &mdio->reset_delay_us);
221 	mdio->reset_post_delay_us = 0;
222 	of_property_read_u32(np, "reset-post-delay-us", &mdio->reset_post_delay_us);
223 
224 	/* Register the MDIO bus */
225 	rc = __mdiobus_register(mdio, owner);
226 	if (rc)
227 		return rc;
228 
229 	/* Loop over the child nodes and register a phy_device for each phy */
230 	rc = __of_mdiobus_parse_phys(mdio, np, &scanphys);
231 	if (rc)
232 		goto unregister;
233 
234 	if (!scanphys)
235 		return 0;
236 
237 	/* auto scan for PHYs with empty reg property */
238 	for_each_available_child_of_node(np, child) {
239 		/* Skip PHYs with reg property set or ethernet-phy-package node */
240 		if (of_property_present(child, "reg") ||
241 		    of_node_name_eq(child, "ethernet-phy-package"))
242 			continue;
243 
244 		for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
245 			/* skip already registered PHYs */
246 			if (mdiobus_is_registered_device(mdio, addr))
247 				continue;
248 
249 			/* be noisy to encourage people to set reg property */
250 			dev_info(&mdio->dev, "scan phy %pOFn at address %i\n",
251 				 child, addr);
252 
253 			if (of_mdiobus_child_is_phy(child)) {
254 				/* -ENODEV is the return code that PHYLIB has
255 				 * standardized on to indicate that bus
256 				 * scanning should continue.
257 				 */
258 				rc = of_mdiobus_register_phy(mdio, child, addr);
259 				if (!rc)
260 					break;
261 				if (rc != -ENODEV)
262 					goto put_unregister;
263 			}
264 		}
265 	}
266 
267 	return 0;
268 
269 put_unregister:
270 	of_node_put(child);
271 unregister:
272 	mdiobus_unregister(mdio);
273 	return rc;
274 }
275 EXPORT_SYMBOL(__of_mdiobus_register);
276 
277 /**
278  * of_mdio_find_device - Given a device tree node, find the mdio_device
279  * @np: pointer to the mdio_device's device tree node
280  *
281  * If successful, returns a pointer to the mdio_device with the embedded
282  * struct device refcount incremented by one, or NULL on failure.
283  * The caller should call put_device() on the mdio_device after its use
284  */
285 struct mdio_device *of_mdio_find_device(struct device_node *np)
286 {
287 	return fwnode_mdio_find_device(of_fwnode_handle(np));
288 }
289 EXPORT_SYMBOL(of_mdio_find_device);
290 
291 /**
292  * of_phy_find_device - Give a PHY node, find the phy_device
293  * @phy_np: Pointer to the phy's device tree node
294  *
295  * If successful, returns a pointer to the phy_device with the embedded
296  * struct device refcount incremented by one, or NULL on failure.
297  */
298 struct phy_device *of_phy_find_device(struct device_node *phy_np)
299 {
300 	return fwnode_phy_find_device(of_fwnode_handle(phy_np));
301 }
302 EXPORT_SYMBOL(of_phy_find_device);
303 
304 /**
305  * of_phy_connect - Connect to the phy described in the device tree
306  * @dev: pointer to net_device claiming the phy
307  * @phy_np: Pointer to device tree node for the PHY
308  * @hndlr: Link state callback for the network device
309  * @flags: flags to pass to the PHY
310  * @iface: PHY data interface type
311  *
312  * If successful, returns a pointer to the phy_device with the embedded
313  * struct device refcount incremented by one, or NULL on failure. The
314  * refcount must be dropped by calling phy_disconnect() or phy_detach().
315  */
316 struct phy_device *of_phy_connect(struct net_device *dev,
317 				  struct device_node *phy_np,
318 				  void (*hndlr)(struct net_device *), u32 flags,
319 				  phy_interface_t iface)
320 {
321 	struct phy_device *phy = of_phy_find_device(phy_np);
322 	int ret;
323 
324 	if (!phy)
325 		return NULL;
326 
327 	phy->dev_flags |= flags;
328 
329 	ret = phy_connect_direct(dev, phy, hndlr, iface);
330 
331 	/* refcount is held by phy_connect_direct() on success */
332 	put_device(&phy->mdio.dev);
333 
334 	return ret ? NULL : phy;
335 }
336 EXPORT_SYMBOL(of_phy_connect);
337 
338 /**
339  * of_phy_get_and_connect
340  * - Get phy node and connect to the phy described in the device tree
341  * @dev: pointer to net_device claiming the phy
342  * @np: Pointer to device tree node for the net_device claiming the phy
343  * @hndlr: Link state callback for the network device
344  *
345  * If successful, returns a pointer to the phy_device with the embedded
346  * struct device refcount incremented by one, or NULL on failure. The
347  * refcount must be dropped by calling phy_disconnect() or phy_detach().
348  */
349 struct phy_device *of_phy_get_and_connect(struct net_device *dev,
350 					  struct device_node *np,
351 					  void (*hndlr)(struct net_device *))
352 {
353 	phy_interface_t iface;
354 	struct device_node *phy_np;
355 	struct phy_device *phy;
356 	int ret;
357 
358 	ret = of_get_phy_mode(np, &iface);
359 	if (ret)
360 		return NULL;
361 	if (of_phy_is_fixed_link(np)) {
362 		ret = of_phy_register_fixed_link(np);
363 		if (ret < 0) {
364 			netdev_err(dev, "broken fixed-link specification\n");
365 			return NULL;
366 		}
367 		phy_np = of_node_get(np);
368 	} else {
369 		phy_np = of_parse_phandle(np, "phy-handle", 0);
370 		if (!phy_np)
371 			return NULL;
372 	}
373 
374 	phy = of_phy_connect(dev, phy_np, hndlr, 0, iface);
375 
376 	of_node_put(phy_np);
377 
378 	return phy;
379 }
380 EXPORT_SYMBOL(of_phy_get_and_connect);
381 
382 /*
383  * of_phy_is_fixed_link() and of_phy_register_fixed_link() must
384  * support two DT bindings:
385  * - the old DT binding, where 'fixed-link' was a property with 5
386  *   cells encoding various information about the fixed PHY
387  * - the new DT binding, where 'fixed-link' is a sub-node of the
388  *   Ethernet device.
389  */
390 bool of_phy_is_fixed_link(struct device_node *np)
391 {
392 	struct device_node *dn;
393 	int len, err;
394 	const char *managed;
395 
396 	/* New binding */
397 	dn = of_get_child_by_name(np, "fixed-link");
398 	if (dn) {
399 		of_node_put(dn);
400 		return true;
401 	}
402 
403 	err = of_property_read_string(np, "managed", &managed);
404 	if (err == 0 && strcmp(managed, "auto") != 0)
405 		return true;
406 
407 	/* Old binding */
408 	if (of_get_property(np, "fixed-link", &len) &&
409 	    len == (5 * sizeof(__be32)))
410 		return true;
411 
412 	return false;
413 }
414 EXPORT_SYMBOL(of_phy_is_fixed_link);
415 
416 int of_phy_register_fixed_link(struct device_node *np)
417 {
418 	struct fixed_phy_status status = {};
419 	struct device_node *fixed_link_node;
420 	u32 fixed_link_prop[5];
421 	const char *managed;
422 
423 	if (of_property_read_string(np, "managed", &managed) == 0 &&
424 	    strcmp(managed, "in-band-status") == 0) {
425 		/* status is zeroed, namely its .link member */
426 		goto register_phy;
427 	}
428 
429 	/* New binding */
430 	fixed_link_node = of_get_child_by_name(np, "fixed-link");
431 	if (fixed_link_node) {
432 		status.link = 1;
433 		status.duplex = of_property_read_bool(fixed_link_node,
434 						      "full-duplex");
435 		if (of_property_read_u32(fixed_link_node, "speed",
436 					 &status.speed)) {
437 			of_node_put(fixed_link_node);
438 			return -EINVAL;
439 		}
440 		status.pause = of_property_read_bool(fixed_link_node, "pause");
441 		status.asym_pause = of_property_read_bool(fixed_link_node,
442 							  "asym-pause");
443 		of_node_put(fixed_link_node);
444 
445 		goto register_phy;
446 	}
447 
448 	/* Old binding */
449 	if (of_property_read_u32_array(np, "fixed-link", fixed_link_prop,
450 				       ARRAY_SIZE(fixed_link_prop)) == 0) {
451 		status.link = 1;
452 		status.duplex = fixed_link_prop[1];
453 		status.speed  = fixed_link_prop[2];
454 		status.pause  = fixed_link_prop[3];
455 		status.asym_pause = fixed_link_prop[4];
456 		goto register_phy;
457 	}
458 
459 	return -ENODEV;
460 
461 register_phy:
462 	return PTR_ERR_OR_ZERO(fixed_phy_register(PHY_POLL, &status, np));
463 }
464 EXPORT_SYMBOL(of_phy_register_fixed_link);
465 
466 void of_phy_deregister_fixed_link(struct device_node *np)
467 {
468 	struct phy_device *phydev;
469 
470 	phydev = of_phy_find_device(np);
471 	if (!phydev)
472 		return;
473 
474 	fixed_phy_unregister(phydev);
475 
476 	put_device(&phydev->mdio.dev);	/* of_phy_find_device() */
477 	phy_device_free(phydev);	/* fixed_phy_register() */
478 }
479 EXPORT_SYMBOL(of_phy_deregister_fixed_link);
480