of_mdio.c

  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
 26MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
 27MODULE_LICENSE("GPL");
 28MODULE_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 */
 32static 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
 37int 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}
 44EXPORT_SYMBOL(of_mdiobus_phy_device_register);
 45
 46static 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
 52static 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 */
 86static 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 */
112bool 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}
137EXPORT_SYMBOL(of_mdiobus_child_is_phy);
138
139static 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;
181exit:
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 */
195int __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
266put_unregister:
267	of_node_put(child);
268unregister:
269	mdiobus_unregister(mdio);
270	return rc;
271}
272EXPORT_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 */
282struct mdio_device *of_mdio_find_device(struct device_node *np)
283{
284	return fwnode_mdio_find_device(of_fwnode_handle(np));
285}
286EXPORT_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 */
295struct phy_device *of_phy_find_device(struct device_node *phy_np)
296{
297	return fwnode_phy_find_device(of_fwnode_handle(phy_np));
298}
299EXPORT_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 */
313struct 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}
333EXPORT_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 */
346struct 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}
377EXPORT_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 */
387bool 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}
410EXPORT_SYMBOL(of_phy_is_fixed_link);
411
412int 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
459register_phy:
460	return PTR_ERR_OR_ZERO(fixed_phy_register(&status, np));
461}
462EXPORT_SYMBOL(of_phy_register_fixed_link);
463
464void 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}
476EXPORT_SYMBOL(of_phy_deregister_fixed_link);