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