1 /*
2  * Broadcom GENET MDIO routines
3  *
4  * Copyright (c) 2014-2017 Broadcom
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 
12 #include <linux/types.h>
13 #include <linux/delay.h>
14 #include <linux/wait.h>
15 #include <linux/mii.h>
16 #include <linux/ethtool.h>
17 #include <linux/bitops.h>
18 #include <linux/netdevice.h>
19 #include <linux/platform_device.h>
20 #include <linux/phy.h>
21 #include <linux/phy_fixed.h>
22 #include <linux/brcmphy.h>
23 #include <linux/of.h>
24 #include <linux/of_net.h>
25 #include <linux/of_mdio.h>
26 #include <linux/platform_data/bcmgenet.h>
27 
28 #include "bcmgenet.h"
29 
30 /* read a value from the MII */
31 static int bcmgenet_mii_read(struct mii_bus *bus, int phy_id, int location)
32 {
33 	int ret;
34 	struct net_device *dev = bus->priv;
35 	struct bcmgenet_priv *priv = netdev_priv(dev);
36 	u32 reg;
37 
38 	bcmgenet_umac_writel(priv, (MDIO_RD | (phy_id << MDIO_PMD_SHIFT) |
39 			     (location << MDIO_REG_SHIFT)), UMAC_MDIO_CMD);
40 	/* Start MDIO transaction*/
41 	reg = bcmgenet_umac_readl(priv, UMAC_MDIO_CMD);
42 	reg |= MDIO_START_BUSY;
43 	bcmgenet_umac_writel(priv, reg, UMAC_MDIO_CMD);
44 	wait_event_timeout(priv->wq,
45 			   !(bcmgenet_umac_readl(priv, UMAC_MDIO_CMD)
46 			   & MDIO_START_BUSY),
47 			   HZ / 100);
48 	ret = bcmgenet_umac_readl(priv, UMAC_MDIO_CMD);
49 
50 	/* Some broken devices are known not to release the line during
51 	 * turn-around, e.g: Broadcom BCM53125 external switches, so check for
52 	 * that condition here and ignore the MDIO controller read failure
53 	 * indication.
54 	 */
55 	if (!(bus->phy_ignore_ta_mask & 1 << phy_id) && (ret & MDIO_READ_FAIL))
56 		return -EIO;
57 
58 	return ret & 0xffff;
59 }
60 
61 /* write a value to the MII */
62 static int bcmgenet_mii_write(struct mii_bus *bus, int phy_id,
63 			      int location, u16 val)
64 {
65 	struct net_device *dev = bus->priv;
66 	struct bcmgenet_priv *priv = netdev_priv(dev);
67 	u32 reg;
68 
69 	bcmgenet_umac_writel(priv, (MDIO_WR | (phy_id << MDIO_PMD_SHIFT) |
70 			     (location << MDIO_REG_SHIFT) | (0xffff & val)),
71 			     UMAC_MDIO_CMD);
72 	reg = bcmgenet_umac_readl(priv, UMAC_MDIO_CMD);
73 	reg |= MDIO_START_BUSY;
74 	bcmgenet_umac_writel(priv, reg, UMAC_MDIO_CMD);
75 	wait_event_timeout(priv->wq,
76 			   !(bcmgenet_umac_readl(priv, UMAC_MDIO_CMD) &
77 			   MDIO_START_BUSY),
78 			   HZ / 100);
79 
80 	return 0;
81 }
82 
83 /* setup netdev link state when PHY link status change and
84  * update UMAC and RGMII block when link up
85  */
86 void bcmgenet_mii_setup(struct net_device *dev)
87 {
88 	struct bcmgenet_priv *priv = netdev_priv(dev);
89 	struct phy_device *phydev = priv->phydev;
90 	u32 reg, cmd_bits = 0;
91 	bool status_changed = false;
92 
93 	if (priv->old_link != phydev->link) {
94 		status_changed = true;
95 		priv->old_link = phydev->link;
96 	}
97 
98 	if (phydev->link) {
99 		/* check speed/duplex/pause changes */
100 		if (priv->old_speed != phydev->speed) {
101 			status_changed = true;
102 			priv->old_speed = phydev->speed;
103 		}
104 
105 		if (priv->old_duplex != phydev->duplex) {
106 			status_changed = true;
107 			priv->old_duplex = phydev->duplex;
108 		}
109 
110 		if (priv->old_pause != phydev->pause) {
111 			status_changed = true;
112 			priv->old_pause = phydev->pause;
113 		}
114 
115 		/* done if nothing has changed */
116 		if (!status_changed)
117 			return;
118 
119 		/* speed */
120 		if (phydev->speed == SPEED_1000)
121 			cmd_bits = UMAC_SPEED_1000;
122 		else if (phydev->speed == SPEED_100)
123 			cmd_bits = UMAC_SPEED_100;
124 		else
125 			cmd_bits = UMAC_SPEED_10;
126 		cmd_bits <<= CMD_SPEED_SHIFT;
127 
128 		/* duplex */
129 		if (phydev->duplex != DUPLEX_FULL)
130 			cmd_bits |= CMD_HD_EN;
131 
132 		/* pause capability */
133 		if (!phydev->pause)
134 			cmd_bits |= CMD_RX_PAUSE_IGNORE | CMD_TX_PAUSE_IGNORE;
135 
136 		/*
137 		 * Program UMAC and RGMII block based on established
138 		 * link speed, duplex, and pause. The speed set in
139 		 * umac->cmd tell RGMII block which clock to use for
140 		 * transmit -- 25MHz(100Mbps) or 125MHz(1Gbps).
141 		 * Receive clock is provided by the PHY.
142 		 */
143 		reg = bcmgenet_ext_readl(priv, EXT_RGMII_OOB_CTRL);
144 		reg &= ~OOB_DISABLE;
145 		reg |= RGMII_LINK;
146 		bcmgenet_ext_writel(priv, reg, EXT_RGMII_OOB_CTRL);
147 
148 		reg = bcmgenet_umac_readl(priv, UMAC_CMD);
149 		reg &= ~((CMD_SPEED_MASK << CMD_SPEED_SHIFT) |
150 			       CMD_HD_EN |
151 			       CMD_RX_PAUSE_IGNORE | CMD_TX_PAUSE_IGNORE);
152 		reg |= cmd_bits;
153 		bcmgenet_umac_writel(priv, reg, UMAC_CMD);
154 	} else {
155 		/* done if nothing has changed */
156 		if (!status_changed)
157 			return;
158 
159 		/* needed for MoCA fixed PHY to reflect correct link status */
160 		netif_carrier_off(dev);
161 	}
162 
163 	phy_print_status(phydev);
164 }
165 
166 
167 static int bcmgenet_fixed_phy_link_update(struct net_device *dev,
168 					  struct fixed_phy_status *status)
169 {
170 	if (dev && dev->phydev && status)
171 		status->link = dev->phydev->link;
172 
173 	return 0;
174 }
175 
176 /* Perform a voluntary PHY software reset, since the EPHY is very finicky about
177  * not doing it and will start corrupting packets
178  */
179 void bcmgenet_mii_reset(struct net_device *dev)
180 {
181 	struct bcmgenet_priv *priv = netdev_priv(dev);
182 
183 	if (GENET_IS_V4(priv))
184 		return;
185 
186 	if (priv->phydev) {
187 		phy_init_hw(priv->phydev);
188 		phy_start_aneg(priv->phydev);
189 	}
190 }
191 
192 void bcmgenet_phy_power_set(struct net_device *dev, bool enable)
193 {
194 	struct bcmgenet_priv *priv = netdev_priv(dev);
195 	u32 reg = 0;
196 
197 	/* EXT_GPHY_CTRL is only valid for GENETv4 and onward */
198 	if (GENET_IS_V4(priv)) {
199 		reg = bcmgenet_ext_readl(priv, EXT_GPHY_CTRL);
200 		if (enable) {
201 			reg &= ~EXT_CK25_DIS;
202 			bcmgenet_ext_writel(priv, reg, EXT_GPHY_CTRL);
203 			mdelay(1);
204 
205 			reg &= ~(EXT_CFG_IDDQ_BIAS | EXT_CFG_PWR_DOWN);
206 			reg |= EXT_GPHY_RESET;
207 			bcmgenet_ext_writel(priv, reg, EXT_GPHY_CTRL);
208 			mdelay(1);
209 
210 			reg &= ~EXT_GPHY_RESET;
211 		} else {
212 			reg |= EXT_CFG_IDDQ_BIAS | EXT_CFG_PWR_DOWN |
213 			       EXT_GPHY_RESET;
214 			bcmgenet_ext_writel(priv, reg, EXT_GPHY_CTRL);
215 			mdelay(1);
216 			reg |= EXT_CK25_DIS;
217 		}
218 		bcmgenet_ext_writel(priv, reg, EXT_GPHY_CTRL);
219 		udelay(60);
220 	} else {
221 		mdelay(1);
222 	}
223 }
224 
225 static void bcmgenet_moca_phy_setup(struct bcmgenet_priv *priv)
226 {
227 	u32 reg;
228 
229 	if (!GENET_IS_V5(priv)) {
230 		/* Speed settings are set in bcmgenet_mii_setup() */
231 		reg = bcmgenet_sys_readl(priv, SYS_PORT_CTRL);
232 		reg |= LED_ACT_SOURCE_MAC;
233 		bcmgenet_sys_writel(priv, reg, SYS_PORT_CTRL);
234 	}
235 
236 	if (priv->hw_params->flags & GENET_HAS_MOCA_LINK_DET)
237 		fixed_phy_set_link_update(priv->phydev,
238 					  bcmgenet_fixed_phy_link_update);
239 }
240 
241 int bcmgenet_mii_config(struct net_device *dev)
242 {
243 	struct bcmgenet_priv *priv = netdev_priv(dev);
244 	struct phy_device *phydev = priv->phydev;
245 	struct device *kdev = &priv->pdev->dev;
246 	const char *phy_name = NULL;
247 	u32 id_mode_dis = 0;
248 	u32 port_ctrl;
249 	u32 reg;
250 
251 	priv->ext_phy = !priv->internal_phy &&
252 			(priv->phy_interface != PHY_INTERFACE_MODE_MOCA);
253 
254 	if (priv->internal_phy)
255 		priv->phy_interface = PHY_INTERFACE_MODE_NA;
256 
257 	switch (priv->phy_interface) {
258 	case PHY_INTERFACE_MODE_NA:
259 	case PHY_INTERFACE_MODE_MOCA:
260 		/* Irrespective of the actually configured PHY speed (100 or
261 		 * 1000) GENETv4 only has an internal GPHY so we will just end
262 		 * up masking the Gigabit features from what we support, not
263 		 * switching to the EPHY
264 		 */
265 		if (GENET_IS_V4(priv))
266 			port_ctrl = PORT_MODE_INT_GPHY;
267 		else
268 			port_ctrl = PORT_MODE_INT_EPHY;
269 
270 		bcmgenet_sys_writel(priv, port_ctrl, SYS_PORT_CTRL);
271 
272 		if (priv->internal_phy) {
273 			phy_name = "internal PHY";
274 		} else if (priv->phy_interface == PHY_INTERFACE_MODE_MOCA) {
275 			phy_name = "MoCA";
276 			bcmgenet_moca_phy_setup(priv);
277 		}
278 		break;
279 
280 	case PHY_INTERFACE_MODE_MII:
281 		phy_name = "external MII";
282 		phydev->supported &= PHY_BASIC_FEATURES;
283 		bcmgenet_sys_writel(priv,
284 				    PORT_MODE_EXT_EPHY, SYS_PORT_CTRL);
285 		break;
286 
287 	case PHY_INTERFACE_MODE_REVMII:
288 		phy_name = "external RvMII";
289 		/* of_mdiobus_register took care of reading the 'max-speed'
290 		 * PHY property for us, effectively limiting the PHY supported
291 		 * capabilities, use that knowledge to also configure the
292 		 * Reverse MII interface correctly.
293 		 */
294 		if ((priv->phydev->supported & PHY_BASIC_FEATURES) ==
295 				PHY_BASIC_FEATURES)
296 			port_ctrl = PORT_MODE_EXT_RVMII_25;
297 		else
298 			port_ctrl = PORT_MODE_EXT_RVMII_50;
299 		bcmgenet_sys_writel(priv, port_ctrl, SYS_PORT_CTRL);
300 		break;
301 
302 	case PHY_INTERFACE_MODE_RGMII:
303 		/* RGMII_NO_ID: TXC transitions at the same time as TXD
304 		 *		(requires PCB or receiver-side delay)
305 		 * RGMII:	Add 2ns delay on TXC (90 degree shift)
306 		 *
307 		 * ID is implicitly disabled for 100Mbps (RG)MII operation.
308 		 */
309 		id_mode_dis = BIT(16);
310 		/* fall through */
311 	case PHY_INTERFACE_MODE_RGMII_TXID:
312 		if (id_mode_dis)
313 			phy_name = "external RGMII (no delay)";
314 		else
315 			phy_name = "external RGMII (TX delay)";
316 		bcmgenet_sys_writel(priv,
317 				    PORT_MODE_EXT_GPHY, SYS_PORT_CTRL);
318 		break;
319 	default:
320 		dev_err(kdev, "unknown phy mode: %d\n", priv->phy_interface);
321 		return -EINVAL;
322 	}
323 
324 	/* This is an external PHY (xMII), so we need to enable the RGMII
325 	 * block for the interface to work
326 	 */
327 	if (priv->ext_phy) {
328 		reg = bcmgenet_ext_readl(priv, EXT_RGMII_OOB_CTRL);
329 		reg |= RGMII_MODE_EN | id_mode_dis;
330 		bcmgenet_ext_writel(priv, reg, EXT_RGMII_OOB_CTRL);
331 	}
332 
333 	dev_info_once(kdev, "configuring instance for %s\n", phy_name);
334 
335 	return 0;
336 }
337 
338 int bcmgenet_mii_probe(struct net_device *dev)
339 {
340 	struct bcmgenet_priv *priv = netdev_priv(dev);
341 	struct device_node *dn = priv->pdev->dev.of_node;
342 	struct phy_device *phydev;
343 	u32 phy_flags;
344 	int ret;
345 
346 	/* Communicate the integrated PHY revision */
347 	phy_flags = priv->gphy_rev;
348 
349 	/* Initialize link state variables that bcmgenet_mii_setup() uses */
350 	priv->old_link = -1;
351 	priv->old_speed = -1;
352 	priv->old_duplex = -1;
353 	priv->old_pause = -1;
354 
355 	if (dn) {
356 		phydev = of_phy_connect(dev, priv->phy_dn, bcmgenet_mii_setup,
357 					phy_flags, priv->phy_interface);
358 		if (!phydev) {
359 			pr_err("could not attach to PHY\n");
360 			return -ENODEV;
361 		}
362 	} else {
363 		phydev = priv->phydev;
364 		phydev->dev_flags = phy_flags;
365 
366 		ret = phy_connect_direct(dev, phydev, bcmgenet_mii_setup,
367 					 priv->phy_interface);
368 		if (ret) {
369 			pr_err("could not attach to PHY\n");
370 			return -ENODEV;
371 		}
372 	}
373 
374 	priv->phydev = phydev;
375 
376 	/* Configure port multiplexer based on what the probed PHY device since
377 	 * reading the 'max-speed' property determines the maximum supported
378 	 * PHY speed which is needed for bcmgenet_mii_config() to configure
379 	 * things appropriately.
380 	 */
381 	ret = bcmgenet_mii_config(dev);
382 	if (ret) {
383 		phy_disconnect(priv->phydev);
384 		return ret;
385 	}
386 
387 	phydev->advertising = phydev->supported;
388 
389 	/* The internal PHY has its link interrupts routed to the
390 	 * Ethernet MAC ISRs
391 	 */
392 	if (priv->internal_phy)
393 		priv->phydev->irq = PHY_IGNORE_INTERRUPT;
394 
395 	return 0;
396 }
397 
398 /* Workaround for integrated BCM7xxx Gigabit PHYs which have a problem with
399  * their internal MDIO management controller making them fail to successfully
400  * be read from or written to for the first transaction.  We insert a dummy
401  * BMSR read here to make sure that phy_get_device() and get_phy_id() can
402  * correctly read the PHY MII_PHYSID1/2 registers and successfully register a
403  * PHY device for this peripheral.
404  *
405  * Once the PHY driver is registered, we can workaround subsequent reads from
406  * there (e.g: during system-wide power management).
407  *
408  * bus->reset is invoked before mdiobus_scan during mdiobus_register and is
409  * therefore the right location to stick that workaround. Since we do not want
410  * to read from non-existing PHYs, we either use bus->phy_mask or do a manual
411  * Device Tree scan to limit the search area.
412  */
413 static int bcmgenet_mii_bus_reset(struct mii_bus *bus)
414 {
415 	struct net_device *dev = bus->priv;
416 	struct bcmgenet_priv *priv = netdev_priv(dev);
417 	struct device_node *np = priv->mdio_dn;
418 	struct device_node *child = NULL;
419 	u32 read_mask = 0;
420 	int addr = 0;
421 
422 	if (!np) {
423 		read_mask = 1 << priv->phy_addr;
424 	} else {
425 		for_each_available_child_of_node(np, child) {
426 			addr = of_mdio_parse_addr(&dev->dev, child);
427 			if (addr < 0)
428 				continue;
429 
430 			read_mask |= 1 << addr;
431 		}
432 	}
433 
434 	for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
435 		if (read_mask & 1 << addr) {
436 			dev_dbg(&dev->dev, "Workaround for PHY @ %d\n", addr);
437 			mdiobus_read(bus, addr, MII_BMSR);
438 		}
439 	}
440 
441 	return 0;
442 }
443 
444 static int bcmgenet_mii_alloc(struct bcmgenet_priv *priv)
445 {
446 	struct mii_bus *bus;
447 
448 	if (priv->mii_bus)
449 		return 0;
450 
451 	priv->mii_bus = mdiobus_alloc();
452 	if (!priv->mii_bus) {
453 		pr_err("failed to allocate\n");
454 		return -ENOMEM;
455 	}
456 
457 	bus = priv->mii_bus;
458 	bus->priv = priv->dev;
459 	bus->name = "bcmgenet MII bus";
460 	bus->parent = &priv->pdev->dev;
461 	bus->read = bcmgenet_mii_read;
462 	bus->write = bcmgenet_mii_write;
463 	bus->reset = bcmgenet_mii_bus_reset;
464 	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d",
465 		 priv->pdev->name, priv->pdev->id);
466 
467 	return 0;
468 }
469 
470 static int bcmgenet_mii_of_init(struct bcmgenet_priv *priv)
471 {
472 	struct device_node *dn = priv->pdev->dev.of_node;
473 	struct device *kdev = &priv->pdev->dev;
474 	const char *phy_mode_str = NULL;
475 	struct phy_device *phydev = NULL;
476 	char *compat;
477 	int phy_mode;
478 	int ret;
479 
480 	compat = kasprintf(GFP_KERNEL, "brcm,genet-mdio-v%d", priv->version);
481 	if (!compat)
482 		return -ENOMEM;
483 
484 	priv->mdio_dn = of_find_compatible_node(dn, NULL, compat);
485 	kfree(compat);
486 	if (!priv->mdio_dn) {
487 		dev_err(kdev, "unable to find MDIO bus node\n");
488 		return -ENODEV;
489 	}
490 
491 	ret = of_mdiobus_register(priv->mii_bus, priv->mdio_dn);
492 	if (ret) {
493 		dev_err(kdev, "failed to register MDIO bus\n");
494 		return ret;
495 	}
496 
497 	/* Fetch the PHY phandle */
498 	priv->phy_dn = of_parse_phandle(dn, "phy-handle", 0);
499 
500 	/* In the case of a fixed PHY, the DT node associated
501 	 * to the PHY is the Ethernet MAC DT node.
502 	 */
503 	if (!priv->phy_dn && of_phy_is_fixed_link(dn)) {
504 		ret = of_phy_register_fixed_link(dn);
505 		if (ret)
506 			return ret;
507 
508 		priv->phy_dn = of_node_get(dn);
509 	}
510 
511 	/* Get the link mode */
512 	phy_mode = of_get_phy_mode(dn);
513 	priv->phy_interface = phy_mode;
514 
515 	/* We need to specifically look up whether this PHY interface is internal
516 	 * or not *before* we even try to probe the PHY driver over MDIO as we
517 	 * may have shut down the internal PHY for power saving purposes.
518 	 */
519 	if (phy_mode < 0) {
520 		ret = of_property_read_string(dn, "phy-mode", &phy_mode_str);
521 		if (ret < 0) {
522 			dev_err(kdev, "invalid PHY mode property\n");
523 			return ret;
524 		}
525 
526 		priv->phy_interface = PHY_INTERFACE_MODE_NA;
527 		if (!strcasecmp(phy_mode_str, "internal"))
528 			priv->internal_phy = true;
529 	}
530 
531 	/* Make sure we initialize MoCA PHYs with a link down */
532 	if (phy_mode == PHY_INTERFACE_MODE_MOCA) {
533 		phydev = of_phy_find_device(dn);
534 		if (phydev) {
535 			phydev->link = 0;
536 			put_device(&phydev->mdio.dev);
537 		}
538 	}
539 
540 	return 0;
541 }
542 
543 static int bcmgenet_mii_pd_init(struct bcmgenet_priv *priv)
544 {
545 	struct device *kdev = &priv->pdev->dev;
546 	struct bcmgenet_platform_data *pd = kdev->platform_data;
547 	struct mii_bus *mdio = priv->mii_bus;
548 	struct phy_device *phydev;
549 	int ret;
550 
551 	if (pd->phy_interface != PHY_INTERFACE_MODE_MOCA && pd->mdio_enabled) {
552 		/*
553 		 * Internal or external PHY with MDIO access
554 		 */
555 		if (pd->phy_address >= 0 && pd->phy_address < PHY_MAX_ADDR)
556 			mdio->phy_mask = ~(1 << pd->phy_address);
557 		else
558 			mdio->phy_mask = 0;
559 
560 		ret = mdiobus_register(mdio);
561 		if (ret) {
562 			dev_err(kdev, "failed to register MDIO bus\n");
563 			return ret;
564 		}
565 
566 		if (pd->phy_address >= 0 && pd->phy_address < PHY_MAX_ADDR)
567 			phydev = mdiobus_get_phy(mdio, pd->phy_address);
568 		else
569 			phydev = phy_find_first(mdio);
570 
571 		if (!phydev) {
572 			dev_err(kdev, "failed to register PHY device\n");
573 			mdiobus_unregister(mdio);
574 			return -ENODEV;
575 		}
576 	} else {
577 		/*
578 		 * MoCA port or no MDIO access.
579 		 * Use fixed PHY to represent the link layer.
580 		 */
581 		struct fixed_phy_status fphy_status = {
582 			.link = 1,
583 			.speed = pd->phy_speed,
584 			.duplex = pd->phy_duplex,
585 			.pause = 0,
586 			.asym_pause = 0,
587 		};
588 
589 		phydev = fixed_phy_register(PHY_POLL, &fphy_status, -1, NULL);
590 		if (!phydev || IS_ERR(phydev)) {
591 			dev_err(kdev, "failed to register fixed PHY device\n");
592 			return -ENODEV;
593 		}
594 
595 		/* Make sure we initialize MoCA PHYs with a link down */
596 		phydev->link = 0;
597 
598 	}
599 
600 	priv->phydev = phydev;
601 	priv->phy_interface = pd->phy_interface;
602 
603 	return 0;
604 }
605 
606 static int bcmgenet_mii_bus_init(struct bcmgenet_priv *priv)
607 {
608 	struct device_node *dn = priv->pdev->dev.of_node;
609 
610 	if (dn)
611 		return bcmgenet_mii_of_init(priv);
612 	else
613 		return bcmgenet_mii_pd_init(priv);
614 }
615 
616 int bcmgenet_mii_init(struct net_device *dev)
617 {
618 	struct bcmgenet_priv *priv = netdev_priv(dev);
619 	struct device_node *dn = priv->pdev->dev.of_node;
620 	int ret;
621 
622 	ret = bcmgenet_mii_alloc(priv);
623 	if (ret)
624 		return ret;
625 
626 	ret = bcmgenet_mii_bus_init(priv);
627 	if (ret)
628 		goto out;
629 
630 	return 0;
631 
632 out:
633 	if (of_phy_is_fixed_link(dn))
634 		of_phy_deregister_fixed_link(dn);
635 	of_node_put(priv->phy_dn);
636 	mdiobus_unregister(priv->mii_bus);
637 	mdiobus_free(priv->mii_bus);
638 	return ret;
639 }
640 
641 void bcmgenet_mii_exit(struct net_device *dev)
642 {
643 	struct bcmgenet_priv *priv = netdev_priv(dev);
644 	struct device_node *dn = priv->pdev->dev.of_node;
645 
646 	if (of_phy_is_fixed_link(dn))
647 		of_phy_deregister_fixed_link(dn);
648 	of_node_put(priv->phy_dn);
649 	mdiobus_unregister(priv->mii_bus);
650 	mdiobus_free(priv->mii_bus);
651 }
652