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/kernel.h>
14#include <linux/module.h>
15#include <linux/netdevice.h>
16#include <linux/of.h>
17#include <linux/of_irq.h>
18#include <linux/of_mdio.h>
19#include <linux/of_net.h>
20#include <linux/phy.h>
21#include <linux/phy_fixed.h>
22
23#define DEFAULT_GPIO_RESET_DELAY	10	/* in microseconds */
24
25MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
26MODULE_LICENSE("GPL");
27
28/* Extract the clause 22 phy ID from the compatible string of the form
29 * ethernet-phy-idAAAA.BBBB */
30static 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
45static 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
63int 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}
105EXPORT_SYMBOL(of_mdiobus_phy_device_register);
106
107static 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
151static 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 */
187static 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 */
213bool 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}
238EXPORT_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 * @owner: module owning the @mdio object.
245 *
246 * This function registers the mii_bus structure and registers a phy_device
247 * for each child node of @np.
248 */
249int __of_mdiobus_register(struct mii_bus *mdio, struct device_node *np,
250			  struct module *owner)
251{
252	struct device_node *child;
253	bool scanphys = false;
254	int addr, rc;
255
256	if (!np)
257		return __mdiobus_register(mdio, owner);
258
259	/* Do not continue if the node is disabled */
260	if (!of_device_is_available(np))
261		return -ENODEV;
262
263	/* Mask out all PHYs from auto probing.  Instead the PHYs listed in
264	 * the device tree are populated after the bus has been registered */
265	mdio->phy_mask = ~0;
266
267	mdio->dev.of_node = np;
268	mdio->dev.fwnode = of_fwnode_handle(np);
269
270	/* Get bus level PHY reset GPIO details */
271	mdio->reset_delay_us = DEFAULT_GPIO_RESET_DELAY;
272	of_property_read_u32(np, "reset-delay-us", &mdio->reset_delay_us);
273	mdio->reset_post_delay_us = 0;
274	of_property_read_u32(np, "reset-post-delay-us", &mdio->reset_post_delay_us);
275
276	/* Register the MDIO bus */
277	rc = __mdiobus_register(mdio, owner);
278	if (rc)
279		return rc;
280
281	/* Loop over the child nodes and register a phy_device for each phy */
282	for_each_available_child_of_node(np, child) {
283		addr = of_mdio_parse_addr(&mdio->dev, child);
284		if (addr < 0) {
285			scanphys = true;
286			continue;
287		}
288
289		if (of_mdiobus_child_is_phy(child))
290			rc = of_mdiobus_register_phy(mdio, child, addr);
291		else
292			rc = of_mdiobus_register_device(mdio, child, addr);
293
294		if (rc == -ENODEV)
295			dev_err(&mdio->dev,
296				"MDIO device at address %d is missing.\n",
297				addr);
298		else if (rc)
299			goto unregister;
300	}
301
302	if (!scanphys)
303		return 0;
304
305	/* auto scan for PHYs with empty reg property */
306	for_each_available_child_of_node(np, child) {
307		/* Skip PHYs with reg property set */
308		if (of_find_property(child, "reg", NULL))
309			continue;
310
311		for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
312			/* skip already registered PHYs */
313			if (mdiobus_is_registered_device(mdio, addr))
314				continue;
315
316			/* be noisy to encourage people to set reg property */
317			dev_info(&mdio->dev, "scan phy %pOFn at address %i\n",
318				 child, addr);
319
320			if (of_mdiobus_child_is_phy(child)) {
321				/* -ENODEV is the return code that PHYLIB has
322				 * standardized on to indicate that bus
323				 * scanning should continue.
324				 */
325				rc = of_mdiobus_register_phy(mdio, child, addr);
326				if (!rc)
327					break;
328				if (rc != -ENODEV)
329					goto unregister;
330			}
331		}
332	}
333
334	return 0;
335
336unregister:
337	of_node_put(child);
338	mdiobus_unregister(mdio);
339	return rc;
340}
341EXPORT_SYMBOL(__of_mdiobus_register);
342
343/**
344 * of_mdio_find_device - Given a device tree node, find the mdio_device
345 * @np: pointer to the mdio_device's device tree node
346 *
347 * If successful, returns a pointer to the mdio_device with the embedded
348 * struct device refcount incremented by one, or NULL on failure.
349 * The caller should call put_device() on the mdio_device after its use
350 */
351struct mdio_device *of_mdio_find_device(struct device_node *np)
352{
353	struct device *d;
354
355	if (!np)
356		return NULL;
357
358	d = bus_find_device_by_of_node(&mdio_bus_type, np);
359	if (!d)
360		return NULL;
361
362	return to_mdio_device(d);
363}
364EXPORT_SYMBOL(of_mdio_find_device);
365
366/**
367 * of_phy_find_device - Give a PHY node, find the phy_device
368 * @phy_np: Pointer to the phy's device tree node
369 *
370 * If successful, returns a pointer to the phy_device with the embedded
371 * struct device refcount incremented by one, or NULL on failure.
372 */
373struct phy_device *of_phy_find_device(struct device_node *phy_np)
374{
375	struct mdio_device *mdiodev;
376
377	mdiodev = of_mdio_find_device(phy_np);
378	if (!mdiodev)
379		return NULL;
380
381	if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY)
382		return to_phy_device(&mdiodev->dev);
383
384	put_device(&mdiodev->dev);
385
386	return NULL;
387}
388EXPORT_SYMBOL(of_phy_find_device);
389
390/**
391 * of_phy_connect - Connect to the phy described in the device tree
392 * @dev: pointer to net_device claiming the phy
393 * @phy_np: Pointer to device tree node for the PHY
394 * @hndlr: Link state callback for the network device
395 * @flags: flags to pass to the PHY
396 * @iface: PHY data interface type
397 *
398 * If successful, returns a pointer to the phy_device with the embedded
399 * struct device refcount incremented by one, or NULL on failure. The
400 * refcount must be dropped by calling phy_disconnect() or phy_detach().
401 */
402struct phy_device *of_phy_connect(struct net_device *dev,
403				  struct device_node *phy_np,
404				  void (*hndlr)(struct net_device *), u32 flags,
405				  phy_interface_t iface)
406{
407	struct phy_device *phy = of_phy_find_device(phy_np);
408	int ret;
409
410	if (!phy)
411		return NULL;
412
413	phy->dev_flags |= flags;
414
415	ret = phy_connect_direct(dev, phy, hndlr, iface);
416
417	/* refcount is held by phy_connect_direct() on success */
418	put_device(&phy->mdio.dev);
419
420	return ret ? NULL : phy;
421}
422EXPORT_SYMBOL(of_phy_connect);
423
424/**
425 * of_phy_get_and_connect
426 * - Get phy node and connect to the phy described in the device tree
427 * @dev: pointer to net_device claiming the phy
428 * @np: Pointer to device tree node for the net_device claiming the phy
429 * @hndlr: Link state callback for the network device
430 *
431 * If successful, returns a pointer to the phy_device with the embedded
432 * struct device refcount incremented by one, or NULL on failure. The
433 * refcount must be dropped by calling phy_disconnect() or phy_detach().
434 */
435struct phy_device *of_phy_get_and_connect(struct net_device *dev,
436					  struct device_node *np,
437					  void (*hndlr)(struct net_device *))
438{
439	phy_interface_t iface;
440	struct device_node *phy_np;
441	struct phy_device *phy;
442	int ret;
443
444	ret = of_get_phy_mode(np, &iface);
445	if (ret)
446		return NULL;
447	if (of_phy_is_fixed_link(np)) {
448		ret = of_phy_register_fixed_link(np);
449		if (ret < 0) {
450			netdev_err(dev, "broken fixed-link specification\n");
451			return NULL;
452		}
453		phy_np = of_node_get(np);
454	} else {
455		phy_np = of_parse_phandle(np, "phy-handle", 0);
456		if (!phy_np)
457			return NULL;
458	}
459
460	phy = of_phy_connect(dev, phy_np, hndlr, 0, iface);
461
462	of_node_put(phy_np);
463
464	return phy;
465}
466EXPORT_SYMBOL(of_phy_get_and_connect);
467
468/**
469 * of_phy_attach - Attach to a PHY without starting the state machine
470 * @dev: pointer to net_device claiming the phy
471 * @phy_np: Node pointer for the PHY
472 * @flags: flags to pass to the PHY
473 * @iface: PHY data interface type
474 *
475 * If successful, returns a pointer to the phy_device with the embedded
476 * struct device refcount incremented by one, or NULL on failure. The
477 * refcount must be dropped by calling phy_disconnect() or phy_detach().
478 */
479struct phy_device *of_phy_attach(struct net_device *dev,
480				 struct device_node *phy_np, u32 flags,
481				 phy_interface_t iface)
482{
483	struct phy_device *phy = of_phy_find_device(phy_np);
484	int ret;
485
486	if (!phy)
487		return NULL;
488
489	ret = phy_attach_direct(dev, phy, flags, iface);
490
491	/* refcount is held by phy_attach_direct() on success */
492	put_device(&phy->mdio.dev);
493
494	return ret ? NULL : phy;
495}
496EXPORT_SYMBOL(of_phy_attach);
497
498/*
499 * of_phy_is_fixed_link() and of_phy_register_fixed_link() must
500 * support two DT bindings:
501 * - the old DT binding, where 'fixed-link' was a property with 5
502 *   cells encoding various informations about the fixed PHY
503 * - the new DT binding, where 'fixed-link' is a sub-node of the
504 *   Ethernet device.
505 */
506bool of_phy_is_fixed_link(struct device_node *np)
507{
508	struct device_node *dn;
509	int len, err;
510	const char *managed;
511
512	/* New binding */
513	dn = of_get_child_by_name(np, "fixed-link");
514	if (dn) {
515		of_node_put(dn);
516		return true;
517	}
518
519	err = of_property_read_string(np, "managed", &managed);
520	if (err == 0 && strcmp(managed, "auto") != 0)
521		return true;
522
523	/* Old binding */
524	if (of_get_property(np, "fixed-link", &len) &&
525	    len == (5 * sizeof(__be32)))
526		return true;
527
528	return false;
529}
530EXPORT_SYMBOL(of_phy_is_fixed_link);
531
532int of_phy_register_fixed_link(struct device_node *np)
533{
534	struct fixed_phy_status status = {};
535	struct device_node *fixed_link_node;
536	u32 fixed_link_prop[5];
537	const char *managed;
538
539	if (of_property_read_string(np, "managed", &managed) == 0 &&
540	    strcmp(managed, "in-band-status") == 0) {
541		/* status is zeroed, namely its .link member */
542		goto register_phy;
543	}
544
545	/* New binding */
546	fixed_link_node = of_get_child_by_name(np, "fixed-link");
547	if (fixed_link_node) {
548		status.link = 1;
549		status.duplex = of_property_read_bool(fixed_link_node,
550						      "full-duplex");
551		if (of_property_read_u32(fixed_link_node, "speed",
552					 &status.speed)) {
553			of_node_put(fixed_link_node);
554			return -EINVAL;
555		}
556		status.pause = of_property_read_bool(fixed_link_node, "pause");
557		status.asym_pause = of_property_read_bool(fixed_link_node,
558							  "asym-pause");
559		of_node_put(fixed_link_node);
560
561		goto register_phy;
562	}
563
564	/* Old binding */
565	if (of_property_read_u32_array(np, "fixed-link", fixed_link_prop,
566				       ARRAY_SIZE(fixed_link_prop)) == 0) {
567		status.link = 1;
568		status.duplex = fixed_link_prop[1];
569		status.speed  = fixed_link_prop[2];
570		status.pause  = fixed_link_prop[3];
571		status.asym_pause = fixed_link_prop[4];
572		goto register_phy;
573	}
574
575	return -ENODEV;
576
577register_phy:
578	return PTR_ERR_OR_ZERO(fixed_phy_register(PHY_POLL, &status, np));
579}
580EXPORT_SYMBOL(of_phy_register_fixed_link);
581
582void of_phy_deregister_fixed_link(struct device_node *np)
583{
584	struct phy_device *phydev;
585
586	phydev = of_phy_find_device(np);
587	if (!phydev)
588		return;
589
590	fixed_phy_unregister(phydev);
591
592	put_device(&phydev->mdio.dev);	/* of_phy_find_device() */
593	phy_device_free(phydev);	/* fixed_phy_register() */
594}
595EXPORT_SYMBOL(of_phy_deregister_fixed_link);
596