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
29 /* Extract the clause 22 phy ID from the compatible string of the form
30 * ethernet-phy-idAAAA.BBBB */
of_get_phy_id(struct device_node * device,u32 * phy_id)31 static int of_get_phy_id(struct device_node *device, u32 *phy_id)
32 {
33 return fwnode_get_phy_id(of_fwnode_handle(device), phy_id);
34 }
35
of_mdiobus_phy_device_register(struct mii_bus * mdio,struct phy_device * phy,struct device_node * child,u32 addr)36 int of_mdiobus_phy_device_register(struct mii_bus *mdio, struct phy_device *phy,
37 struct device_node *child, u32 addr)
38 {
39 return fwnode_mdiobus_phy_device_register(mdio, phy,
40 of_fwnode_handle(child),
41 addr);
42 }
43 EXPORT_SYMBOL(of_mdiobus_phy_device_register);
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 return fwnode_mdiobus_register_phy(mdio, of_fwnode_handle(child), addr);
49 }
50
of_mdiobus_register_device(struct mii_bus * mdio,struct device_node * child,u32 addr)51 static int of_mdiobus_register_device(struct mii_bus *mdio,
52 struct device_node *child, u32 addr)
53 {
54 struct fwnode_handle *fwnode = of_fwnode_handle(child);
55 struct mdio_device *mdiodev;
56 int rc;
57
58 mdiodev = mdio_device_create(mdio, addr);
59 if (IS_ERR(mdiodev))
60 return PTR_ERR(mdiodev);
61
62 /* Associate the OF node with the device structure so it
63 * can be looked up later.
64 */
65 fwnode_handle_get(fwnode);
66 device_set_node(&mdiodev->dev, fwnode);
67
68 /* All data is now stored in the mdiodev struct; register it. */
69 rc = mdio_device_register(mdiodev);
70 if (rc) {
71 device_set_node(&mdiodev->dev, NULL);
72 fwnode_handle_put(fwnode);
73 mdio_device_free(mdiodev);
74 return rc;
75 }
76
77 dev_dbg(&mdio->dev, "registered mdio device %pOFn at address %i\n",
78 child, addr);
79 return 0;
80 }
81
82 /* The following is a list of PHY compatible strings which appear in
83 * some DTBs. The compatible string is never matched against a PHY
84 * driver, so is pointless. We only expect devices which are not PHYs
85 * to have a compatible string, so they can be matched to an MDIO
86 * driver. Encourage users to upgrade their DT blobs to remove these.
87 */
88 static const struct of_device_id whitelist_phys[] = {
89 { .compatible = "brcm,40nm-ephy" },
90 { .compatible = "broadcom,bcm5241" },
91 { .compatible = "marvell,88E1111", },
92 { .compatible = "marvell,88e1116", },
93 { .compatible = "marvell,88e1118", },
94 { .compatible = "marvell,88e1145", },
95 { .compatible = "marvell,88e1149r", },
96 { .compatible = "marvell,88e1310", },
97 { .compatible = "marvell,88E1510", },
98 { .compatible = "marvell,88E1514", },
99 { .compatible = "moxa,moxart-rtl8201cp", },
100 {}
101 };
102
103 /*
104 * Return true if the child node is for a phy. It must either:
105 * o Compatible string of "ethernet-phy-idX.X"
106 * o Compatible string of "ethernet-phy-ieee802.3-c45"
107 * o Compatible string of "ethernet-phy-ieee802.3-c22"
108 * o In the white list above (and issue a warning)
109 * o No compatibility string
110 *
111 * A device which is not a phy is expected to have a compatible string
112 * indicating what sort of device it is.
113 */
of_mdiobus_child_is_phy(struct device_node * child)114 bool of_mdiobus_child_is_phy(struct device_node *child)
115 {
116 u32 phy_id;
117
118 if (of_get_phy_id(child, &phy_id) != -EINVAL)
119 return true;
120
121 if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c45"))
122 return true;
123
124 if (of_device_is_compatible(child, "ethernet-phy-ieee802.3-c22"))
125 return true;
126
127 if (of_match_node(whitelist_phys, child)) {
128 pr_warn(FW_WARN
129 "%pOF: Whitelisted compatible string. Please remove\n",
130 child);
131 return true;
132 }
133
134 if (!of_property_present(child, "compatible"))
135 return true;
136
137 return false;
138 }
139 EXPORT_SYMBOL(of_mdiobus_child_is_phy);
140
141 /**
142 * __of_mdiobus_register - Register mii_bus and create PHYs from the device tree
143 * @mdio: pointer to mii_bus structure
144 * @np: pointer to device_node of MDIO bus.
145 * @owner: module owning the @mdio object.
146 *
147 * This function registers the mii_bus structure and registers a phy_device
148 * for each child node of @np.
149 */
__of_mdiobus_register(struct mii_bus * mdio,struct device_node * np,struct module * owner)150 int __of_mdiobus_register(struct mii_bus *mdio, struct device_node *np,
151 struct module *owner)
152 {
153 struct device_node *child;
154 bool scanphys = false;
155 int addr, rc;
156
157 if (!np)
158 return __mdiobus_register(mdio, owner);
159
160 /* Do not continue if the node is disabled */
161 if (!of_device_is_available(np))
162 return -ENODEV;
163
164 /* Mask out all PHYs from auto probing. Instead the PHYs listed in
165 * the device tree are populated after the bus has been registered */
166 mdio->phy_mask = ~0;
167
168 device_set_node(&mdio->dev, of_fwnode_handle(np));
169
170 /* Get bus level PHY reset GPIO details */
171 mdio->reset_delay_us = DEFAULT_GPIO_RESET_DELAY;
172 of_property_read_u32(np, "reset-delay-us", &mdio->reset_delay_us);
173 mdio->reset_post_delay_us = 0;
174 of_property_read_u32(np, "reset-post-delay-us", &mdio->reset_post_delay_us);
175
176 /* Register the MDIO bus */
177 rc = __mdiobus_register(mdio, owner);
178 if (rc)
179 return rc;
180
181 /* Loop over the child nodes and register a phy_device for each phy */
182 for_each_available_child_of_node(np, child) {
183 addr = of_mdio_parse_addr(&mdio->dev, child);
184 if (addr < 0) {
185 scanphys = true;
186 continue;
187 }
188
189 if (of_mdiobus_child_is_phy(child))
190 rc = of_mdiobus_register_phy(mdio, child, addr);
191 else
192 rc = of_mdiobus_register_device(mdio, child, addr);
193
194 if (rc == -ENODEV)
195 dev_err(&mdio->dev,
196 "MDIO device at address %d is missing.\n",
197 addr);
198 else if (rc)
199 goto unregister;
200 }
201
202 if (!scanphys)
203 return 0;
204
205 /* auto scan for PHYs with empty reg property */
206 for_each_available_child_of_node(np, child) {
207 /* Skip PHYs with reg property set */
208 if (of_property_present(child, "reg"))
209 continue;
210
211 for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
212 /* skip already registered PHYs */
213 if (mdiobus_is_registered_device(mdio, addr))
214 continue;
215
216 /* be noisy to encourage people to set reg property */
217 dev_info(&mdio->dev, "scan phy %pOFn at address %i\n",
218 child, addr);
219
220 if (of_mdiobus_child_is_phy(child)) {
221 /* -ENODEV is the return code that PHYLIB has
222 * standardized on to indicate that bus
223 * scanning should continue.
224 */
225 rc = of_mdiobus_register_phy(mdio, child, addr);
226 if (!rc)
227 break;
228 if (rc != -ENODEV)
229 goto unregister;
230 }
231 }
232 }
233
234 return 0;
235
236 unregister:
237 of_node_put(child);
238 mdiobus_unregister(mdio);
239 return rc;
240 }
241 EXPORT_SYMBOL(__of_mdiobus_register);
242
243 /**
244 * of_mdio_find_device - Given a device tree node, find the mdio_device
245 * @np: pointer to the mdio_device's device tree node
246 *
247 * If successful, returns a pointer to the mdio_device with the embedded
248 * struct device refcount incremented by one, or NULL on failure.
249 * The caller should call put_device() on the mdio_device after its use
250 */
of_mdio_find_device(struct device_node * np)251 struct mdio_device *of_mdio_find_device(struct device_node *np)
252 {
253 return fwnode_mdio_find_device(of_fwnode_handle(np));
254 }
255 EXPORT_SYMBOL(of_mdio_find_device);
256
257 /**
258 * of_phy_find_device - Give a PHY node, find the phy_device
259 * @phy_np: Pointer to the phy's device tree node
260 *
261 * If successful, returns a pointer to the phy_device with the embedded
262 * struct device refcount incremented by one, or NULL on failure.
263 */
of_phy_find_device(struct device_node * phy_np)264 struct phy_device *of_phy_find_device(struct device_node *phy_np)
265 {
266 return fwnode_phy_find_device(of_fwnode_handle(phy_np));
267 }
268 EXPORT_SYMBOL(of_phy_find_device);
269
270 /**
271 * of_phy_connect - Connect to the phy described in the device tree
272 * @dev: pointer to net_device claiming the phy
273 * @phy_np: Pointer to device tree node for the PHY
274 * @hndlr: Link state callback for the network device
275 * @flags: flags to pass to the PHY
276 * @iface: PHY data interface type
277 *
278 * If successful, returns a pointer to the phy_device with the embedded
279 * struct device refcount incremented by one, or NULL on failure. The
280 * refcount must be dropped by calling phy_disconnect() or phy_detach().
281 */
of_phy_connect(struct net_device * dev,struct device_node * phy_np,void (* hndlr)(struct net_device *),u32 flags,phy_interface_t iface)282 struct phy_device *of_phy_connect(struct net_device *dev,
283 struct device_node *phy_np,
284 void (*hndlr)(struct net_device *), u32 flags,
285 phy_interface_t iface)
286 {
287 struct phy_device *phy = of_phy_find_device(phy_np);
288 int ret;
289
290 if (!phy)
291 return NULL;
292
293 phy->dev_flags |= flags;
294
295 ret = phy_connect_direct(dev, phy, hndlr, iface);
296
297 /* refcount is held by phy_connect_direct() on success */
298 put_device(&phy->mdio.dev);
299
300 return ret ? NULL : phy;
301 }
302 EXPORT_SYMBOL(of_phy_connect);
303
304 /**
305 * of_phy_get_and_connect
306 * - Get phy node and connect to the phy described in the device tree
307 * @dev: pointer to net_device claiming the phy
308 * @np: Pointer to device tree node for the net_device claiming the phy
309 * @hndlr: Link state callback for the network device
310 *
311 * If successful, returns a pointer to the phy_device with the embedded
312 * struct device refcount incremented by one, or NULL on failure. The
313 * refcount must be dropped by calling phy_disconnect() or phy_detach().
314 */
of_phy_get_and_connect(struct net_device * dev,struct device_node * np,void (* hndlr)(struct net_device *))315 struct phy_device *of_phy_get_and_connect(struct net_device *dev,
316 struct device_node *np,
317 void (*hndlr)(struct net_device *))
318 {
319 phy_interface_t iface;
320 struct device_node *phy_np;
321 struct phy_device *phy;
322 int ret;
323
324 ret = of_get_phy_mode(np, &iface);
325 if (ret)
326 return NULL;
327 if (of_phy_is_fixed_link(np)) {
328 ret = of_phy_register_fixed_link(np);
329 if (ret < 0) {
330 netdev_err(dev, "broken fixed-link specification\n");
331 return NULL;
332 }
333 phy_np = of_node_get(np);
334 } else {
335 phy_np = of_parse_phandle(np, "phy-handle", 0);
336 if (!phy_np)
337 return NULL;
338 }
339
340 phy = of_phy_connect(dev, phy_np, hndlr, 0, iface);
341
342 of_node_put(phy_np);
343
344 return phy;
345 }
346 EXPORT_SYMBOL(of_phy_get_and_connect);
347
348 /*
349 * of_phy_is_fixed_link() and of_phy_register_fixed_link() must
350 * support two DT bindings:
351 * - the old DT binding, where 'fixed-link' was a property with 5
352 * cells encoding various information about the fixed PHY
353 * - the new DT binding, where 'fixed-link' is a sub-node of the
354 * Ethernet device.
355 */
of_phy_is_fixed_link(struct device_node * np)356 bool of_phy_is_fixed_link(struct device_node *np)
357 {
358 struct device_node *dn;
359 int len, err;
360 const char *managed;
361
362 /* New binding */
363 dn = of_get_child_by_name(np, "fixed-link");
364 if (dn) {
365 of_node_put(dn);
366 return true;
367 }
368
369 err = of_property_read_string(np, "managed", &managed);
370 if (err == 0 && strcmp(managed, "auto") != 0)
371 return true;
372
373 /* Old binding */
374 if (of_get_property(np, "fixed-link", &len) &&
375 len == (5 * sizeof(__be32)))
376 return true;
377
378 return false;
379 }
380 EXPORT_SYMBOL(of_phy_is_fixed_link);
381
of_phy_register_fixed_link(struct device_node * np)382 int of_phy_register_fixed_link(struct device_node *np)
383 {
384 struct fixed_phy_status status = {};
385 struct device_node *fixed_link_node;
386 u32 fixed_link_prop[5];
387 const char *managed;
388
389 if (of_property_read_string(np, "managed", &managed) == 0 &&
390 strcmp(managed, "in-band-status") == 0) {
391 /* status is zeroed, namely its .link member */
392 goto register_phy;
393 }
394
395 /* New binding */
396 fixed_link_node = of_get_child_by_name(np, "fixed-link");
397 if (fixed_link_node) {
398 status.link = 1;
399 status.duplex = of_property_read_bool(fixed_link_node,
400 "full-duplex");
401 if (of_property_read_u32(fixed_link_node, "speed",
402 &status.speed)) {
403 of_node_put(fixed_link_node);
404 return -EINVAL;
405 }
406 status.pause = of_property_read_bool(fixed_link_node, "pause");
407 status.asym_pause = of_property_read_bool(fixed_link_node,
408 "asym-pause");
409 of_node_put(fixed_link_node);
410
411 goto register_phy;
412 }
413
414 /* Old binding */
415 if (of_property_read_u32_array(np, "fixed-link", fixed_link_prop,
416 ARRAY_SIZE(fixed_link_prop)) == 0) {
417 status.link = 1;
418 status.duplex = fixed_link_prop[1];
419 status.speed = fixed_link_prop[2];
420 status.pause = fixed_link_prop[3];
421 status.asym_pause = fixed_link_prop[4];
422 goto register_phy;
423 }
424
425 return -ENODEV;
426
427 register_phy:
428 return PTR_ERR_OR_ZERO(fixed_phy_register(PHY_POLL, &status, np));
429 }
430 EXPORT_SYMBOL(of_phy_register_fixed_link);
431
of_phy_deregister_fixed_link(struct device_node * np)432 void of_phy_deregister_fixed_link(struct device_node *np)
433 {
434 struct phy_device *phydev;
435
436 phydev = of_phy_find_device(np);
437 if (!phydev)
438 return;
439
440 fixed_phy_unregister(phydev);
441
442 put_device(&phydev->mdio.dev); /* of_phy_find_device() */
443 phy_device_free(phydev); /* fixed_phy_register() */
444 }
445 EXPORT_SYMBOL(of_phy_deregister_fixed_link);
446