xref: /linux/drivers/net/ethernet/broadcom/genet/bcmmii.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /*
2  * Broadcom GENET MDIO routines
3  *
4  * Copyright (c) 2014 Broadcom Corporation
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 		return;
200 
201 	reg = bcmgenet_ext_readl(priv, EXT_GPHY_CTRL);
202 	if (enable) {
203 		reg &= ~EXT_CK25_DIS;
204 		bcmgenet_ext_writel(priv, reg, EXT_GPHY_CTRL);
205 		mdelay(1);
206 
207 		reg &= ~(EXT_CFG_IDDQ_BIAS | EXT_CFG_PWR_DOWN);
208 		reg |= EXT_GPHY_RESET;
209 		bcmgenet_ext_writel(priv, reg, EXT_GPHY_CTRL);
210 		mdelay(1);
211 
212 		reg &= ~EXT_GPHY_RESET;
213 	} else {
214 		reg |= EXT_CFG_IDDQ_BIAS | EXT_CFG_PWR_DOWN | EXT_GPHY_RESET;
215 		bcmgenet_ext_writel(priv, reg, EXT_GPHY_CTRL);
216 		mdelay(1);
217 		reg |= EXT_CK25_DIS;
218 	}
219 	bcmgenet_ext_writel(priv, reg, EXT_GPHY_CTRL);
220 	udelay(60);
221 }
222 
223 static void bcmgenet_moca_phy_setup(struct bcmgenet_priv *priv)
224 {
225 	u32 reg;
226 
227 	/* Speed settings are set in bcmgenet_mii_setup() */
228 	reg = bcmgenet_sys_readl(priv, SYS_PORT_CTRL);
229 	reg |= LED_ACT_SOURCE_MAC;
230 	bcmgenet_sys_writel(priv, reg, SYS_PORT_CTRL);
231 
232 	if (priv->hw_params->flags & GENET_HAS_MOCA_LINK_DET)
233 		fixed_phy_set_link_update(priv->phydev,
234 					  bcmgenet_fixed_phy_link_update);
235 }
236 
237 int bcmgenet_mii_config(struct net_device *dev)
238 {
239 	struct bcmgenet_priv *priv = netdev_priv(dev);
240 	struct phy_device *phydev = priv->phydev;
241 	struct device *kdev = &priv->pdev->dev;
242 	const char *phy_name = NULL;
243 	u32 id_mode_dis = 0;
244 	u32 port_ctrl;
245 	u32 reg;
246 
247 	priv->ext_phy = !priv->internal_phy &&
248 			(priv->phy_interface != PHY_INTERFACE_MODE_MOCA);
249 
250 	if (priv->internal_phy)
251 		priv->phy_interface = PHY_INTERFACE_MODE_NA;
252 
253 	switch (priv->phy_interface) {
254 	case PHY_INTERFACE_MODE_NA:
255 	case PHY_INTERFACE_MODE_MOCA:
256 		/* Irrespective of the actually configured PHY speed (100 or
257 		 * 1000) GENETv4 only has an internal GPHY so we will just end
258 		 * up masking the Gigabit features from what we support, not
259 		 * switching to the EPHY
260 		 */
261 		if (GENET_IS_V4(priv))
262 			port_ctrl = PORT_MODE_INT_GPHY;
263 		else
264 			port_ctrl = PORT_MODE_INT_EPHY;
265 
266 		bcmgenet_sys_writel(priv, port_ctrl, SYS_PORT_CTRL);
267 
268 		if (priv->internal_phy) {
269 			phy_name = "internal PHY";
270 		} else if (priv->phy_interface == PHY_INTERFACE_MODE_MOCA) {
271 			phy_name = "MoCA";
272 			bcmgenet_moca_phy_setup(priv);
273 		}
274 		break;
275 
276 	case PHY_INTERFACE_MODE_MII:
277 		phy_name = "external MII";
278 		phydev->supported &= PHY_BASIC_FEATURES;
279 		bcmgenet_sys_writel(priv,
280 				    PORT_MODE_EXT_EPHY, SYS_PORT_CTRL);
281 		break;
282 
283 	case PHY_INTERFACE_MODE_REVMII:
284 		phy_name = "external RvMII";
285 		/* of_mdiobus_register took care of reading the 'max-speed'
286 		 * PHY property for us, effectively limiting the PHY supported
287 		 * capabilities, use that knowledge to also configure the
288 		 * Reverse MII interface correctly.
289 		 */
290 		if ((priv->phydev->supported & PHY_BASIC_FEATURES) ==
291 				PHY_BASIC_FEATURES)
292 			port_ctrl = PORT_MODE_EXT_RVMII_25;
293 		else
294 			port_ctrl = PORT_MODE_EXT_RVMII_50;
295 		bcmgenet_sys_writel(priv, port_ctrl, SYS_PORT_CTRL);
296 		break;
297 
298 	case PHY_INTERFACE_MODE_RGMII:
299 		/* RGMII_NO_ID: TXC transitions at the same time as TXD
300 		 *		(requires PCB or receiver-side delay)
301 		 * RGMII:	Add 2ns delay on TXC (90 degree shift)
302 		 *
303 		 * ID is implicitly disabled for 100Mbps (RG)MII operation.
304 		 */
305 		id_mode_dis = BIT(16);
306 		/* fall through */
307 	case PHY_INTERFACE_MODE_RGMII_TXID:
308 		if (id_mode_dis)
309 			phy_name = "external RGMII (no delay)";
310 		else
311 			phy_name = "external RGMII (TX delay)";
312 		bcmgenet_sys_writel(priv,
313 				    PORT_MODE_EXT_GPHY, SYS_PORT_CTRL);
314 		break;
315 	default:
316 		dev_err(kdev, "unknown phy mode: %d\n", priv->phy_interface);
317 		return -EINVAL;
318 	}
319 
320 	/* This is an external PHY (xMII), so we need to enable the RGMII
321 	 * block for the interface to work
322 	 */
323 	if (priv->ext_phy) {
324 		reg = bcmgenet_ext_readl(priv, EXT_RGMII_OOB_CTRL);
325 		reg |= RGMII_MODE_EN | id_mode_dis;
326 		bcmgenet_ext_writel(priv, reg, EXT_RGMII_OOB_CTRL);
327 	}
328 
329 	dev_info_once(kdev, "configuring instance for %s\n", phy_name);
330 
331 	return 0;
332 }
333 
334 int bcmgenet_mii_probe(struct net_device *dev)
335 {
336 	struct bcmgenet_priv *priv = netdev_priv(dev);
337 	struct device_node *dn = priv->pdev->dev.of_node;
338 	struct phy_device *phydev;
339 	u32 phy_flags;
340 	int ret;
341 
342 	/* Communicate the integrated PHY revision */
343 	phy_flags = priv->gphy_rev;
344 
345 	/* Initialize link state variables that bcmgenet_mii_setup() uses */
346 	priv->old_link = -1;
347 	priv->old_speed = -1;
348 	priv->old_duplex = -1;
349 	priv->old_pause = -1;
350 
351 	if (dn) {
352 		phydev = of_phy_connect(dev, priv->phy_dn, bcmgenet_mii_setup,
353 					phy_flags, priv->phy_interface);
354 		if (!phydev) {
355 			pr_err("could not attach to PHY\n");
356 			return -ENODEV;
357 		}
358 	} else {
359 		phydev = priv->phydev;
360 		phydev->dev_flags = phy_flags;
361 
362 		ret = phy_connect_direct(dev, phydev, bcmgenet_mii_setup,
363 					 priv->phy_interface);
364 		if (ret) {
365 			pr_err("could not attach to PHY\n");
366 			return -ENODEV;
367 		}
368 	}
369 
370 	priv->phydev = phydev;
371 
372 	/* Configure port multiplexer based on what the probed PHY device since
373 	 * reading the 'max-speed' property determines the maximum supported
374 	 * PHY speed which is needed for bcmgenet_mii_config() to configure
375 	 * things appropriately.
376 	 */
377 	ret = bcmgenet_mii_config(dev);
378 	if (ret) {
379 		phy_disconnect(priv->phydev);
380 		return ret;
381 	}
382 
383 	phydev->advertising = phydev->supported;
384 
385 	/* The internal PHY has its link interrupts routed to the
386 	 * Ethernet MAC ISRs
387 	 */
388 	if (priv->internal_phy)
389 		priv->phydev->irq = PHY_IGNORE_INTERRUPT;
390 
391 	return 0;
392 }
393 
394 /* Workaround for integrated BCM7xxx Gigabit PHYs which have a problem with
395  * their internal MDIO management controller making them fail to successfully
396  * be read from or written to for the first transaction.  We insert a dummy
397  * BMSR read here to make sure that phy_get_device() and get_phy_id() can
398  * correctly read the PHY MII_PHYSID1/2 registers and successfully register a
399  * PHY device for this peripheral.
400  *
401  * Once the PHY driver is registered, we can workaround subsequent reads from
402  * there (e.g: during system-wide power management).
403  *
404  * bus->reset is invoked before mdiobus_scan during mdiobus_register and is
405  * therefore the right location to stick that workaround. Since we do not want
406  * to read from non-existing PHYs, we either use bus->phy_mask or do a manual
407  * Device Tree scan to limit the search area.
408  */
409 static int bcmgenet_mii_bus_reset(struct mii_bus *bus)
410 {
411 	struct net_device *dev = bus->priv;
412 	struct bcmgenet_priv *priv = netdev_priv(dev);
413 	struct device_node *np = priv->mdio_dn;
414 	struct device_node *child = NULL;
415 	u32 read_mask = 0;
416 	int addr = 0;
417 
418 	if (!np) {
419 		read_mask = 1 << priv->phy_addr;
420 	} else {
421 		for_each_available_child_of_node(np, child) {
422 			addr = of_mdio_parse_addr(&dev->dev, child);
423 			if (addr < 0)
424 				continue;
425 
426 			read_mask |= 1 << addr;
427 		}
428 	}
429 
430 	for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
431 		if (read_mask & 1 << addr) {
432 			dev_dbg(&dev->dev, "Workaround for PHY @ %d\n", addr);
433 			mdiobus_read(bus, addr, MII_BMSR);
434 		}
435 	}
436 
437 	return 0;
438 }
439 
440 static int bcmgenet_mii_alloc(struct bcmgenet_priv *priv)
441 {
442 	struct mii_bus *bus;
443 
444 	if (priv->mii_bus)
445 		return 0;
446 
447 	priv->mii_bus = mdiobus_alloc();
448 	if (!priv->mii_bus) {
449 		pr_err("failed to allocate\n");
450 		return -ENOMEM;
451 	}
452 
453 	bus = priv->mii_bus;
454 	bus->priv = priv->dev;
455 	bus->name = "bcmgenet MII bus";
456 	bus->parent = &priv->pdev->dev;
457 	bus->read = bcmgenet_mii_read;
458 	bus->write = bcmgenet_mii_write;
459 	bus->reset = bcmgenet_mii_bus_reset;
460 	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d",
461 		 priv->pdev->name, priv->pdev->id);
462 
463 	return 0;
464 }
465 
466 static int bcmgenet_mii_of_init(struct bcmgenet_priv *priv)
467 {
468 	struct device_node *dn = priv->pdev->dev.of_node;
469 	struct device *kdev = &priv->pdev->dev;
470 	const char *phy_mode_str = NULL;
471 	struct phy_device *phydev = NULL;
472 	char *compat;
473 	int phy_mode;
474 	int ret;
475 
476 	compat = kasprintf(GFP_KERNEL, "brcm,genet-mdio-v%d", priv->version);
477 	if (!compat)
478 		return -ENOMEM;
479 
480 	priv->mdio_dn = of_find_compatible_node(dn, NULL, compat);
481 	kfree(compat);
482 	if (!priv->mdio_dn) {
483 		dev_err(kdev, "unable to find MDIO bus node\n");
484 		return -ENODEV;
485 	}
486 
487 	ret = of_mdiobus_register(priv->mii_bus, priv->mdio_dn);
488 	if (ret) {
489 		dev_err(kdev, "failed to register MDIO bus\n");
490 		return ret;
491 	}
492 
493 	/* Fetch the PHY phandle */
494 	priv->phy_dn = of_parse_phandle(dn, "phy-handle", 0);
495 
496 	/* In the case of a fixed PHY, the DT node associated
497 	 * to the PHY is the Ethernet MAC DT node.
498 	 */
499 	if (!priv->phy_dn && of_phy_is_fixed_link(dn)) {
500 		ret = of_phy_register_fixed_link(dn);
501 		if (ret)
502 			return ret;
503 
504 		priv->phy_dn = of_node_get(dn);
505 	}
506 
507 	/* Get the link mode */
508 	phy_mode = of_get_phy_mode(dn);
509 	priv->phy_interface = phy_mode;
510 
511 	/* We need to specifically look up whether this PHY interface is internal
512 	 * or not *before* we even try to probe the PHY driver over MDIO as we
513 	 * may have shut down the internal PHY for power saving purposes.
514 	 */
515 	if (phy_mode < 0) {
516 		ret = of_property_read_string(dn, "phy-mode", &phy_mode_str);
517 		if (ret < 0) {
518 			dev_err(kdev, "invalid PHY mode property\n");
519 			return ret;
520 		}
521 
522 		priv->phy_interface = PHY_INTERFACE_MODE_NA;
523 		if (!strcasecmp(phy_mode_str, "internal"))
524 			priv->internal_phy = true;
525 	}
526 
527 	/* Make sure we initialize MoCA PHYs with a link down */
528 	if (phy_mode == PHY_INTERFACE_MODE_MOCA) {
529 		phydev = of_phy_find_device(dn);
530 		if (phydev) {
531 			phydev->link = 0;
532 			put_device(&phydev->mdio.dev);
533 		}
534 	}
535 
536 	return 0;
537 }
538 
539 static int bcmgenet_mii_pd_init(struct bcmgenet_priv *priv)
540 {
541 	struct device *kdev = &priv->pdev->dev;
542 	struct bcmgenet_platform_data *pd = kdev->platform_data;
543 	struct mii_bus *mdio = priv->mii_bus;
544 	struct phy_device *phydev;
545 	int ret;
546 
547 	if (pd->phy_interface != PHY_INTERFACE_MODE_MOCA && pd->mdio_enabled) {
548 		/*
549 		 * Internal or external PHY with MDIO access
550 		 */
551 		if (pd->phy_address >= 0 && pd->phy_address < PHY_MAX_ADDR)
552 			mdio->phy_mask = ~(1 << pd->phy_address);
553 		else
554 			mdio->phy_mask = 0;
555 
556 		ret = mdiobus_register(mdio);
557 		if (ret) {
558 			dev_err(kdev, "failed to register MDIO bus\n");
559 			return ret;
560 		}
561 
562 		if (pd->phy_address >= 0 && pd->phy_address < PHY_MAX_ADDR)
563 			phydev = mdiobus_get_phy(mdio, pd->phy_address);
564 		else
565 			phydev = phy_find_first(mdio);
566 
567 		if (!phydev) {
568 			dev_err(kdev, "failed to register PHY device\n");
569 			mdiobus_unregister(mdio);
570 			return -ENODEV;
571 		}
572 	} else {
573 		/*
574 		 * MoCA port or no MDIO access.
575 		 * Use fixed PHY to represent the link layer.
576 		 */
577 		struct fixed_phy_status fphy_status = {
578 			.link = 1,
579 			.speed = pd->phy_speed,
580 			.duplex = pd->phy_duplex,
581 			.pause = 0,
582 			.asym_pause = 0,
583 		};
584 
585 		phydev = fixed_phy_register(PHY_POLL, &fphy_status, -1, NULL);
586 		if (!phydev || IS_ERR(phydev)) {
587 			dev_err(kdev, "failed to register fixed PHY device\n");
588 			return -ENODEV;
589 		}
590 
591 		/* Make sure we initialize MoCA PHYs with a link down */
592 		phydev->link = 0;
593 
594 	}
595 
596 	priv->phydev = phydev;
597 	priv->phy_interface = pd->phy_interface;
598 
599 	return 0;
600 }
601 
602 static int bcmgenet_mii_bus_init(struct bcmgenet_priv *priv)
603 {
604 	struct device_node *dn = priv->pdev->dev.of_node;
605 
606 	if (dn)
607 		return bcmgenet_mii_of_init(priv);
608 	else
609 		return bcmgenet_mii_pd_init(priv);
610 }
611 
612 int bcmgenet_mii_init(struct net_device *dev)
613 {
614 	struct bcmgenet_priv *priv = netdev_priv(dev);
615 	struct device_node *dn = priv->pdev->dev.of_node;
616 	int ret;
617 
618 	ret = bcmgenet_mii_alloc(priv);
619 	if (ret)
620 		return ret;
621 
622 	ret = bcmgenet_mii_bus_init(priv);
623 	if (ret)
624 		goto out;
625 
626 	return 0;
627 
628 out:
629 	if (of_phy_is_fixed_link(dn))
630 		of_phy_deregister_fixed_link(dn);
631 	of_node_put(priv->phy_dn);
632 	mdiobus_unregister(priv->mii_bus);
633 	mdiobus_free(priv->mii_bus);
634 	return ret;
635 }
636 
637 void bcmgenet_mii_exit(struct net_device *dev)
638 {
639 	struct bcmgenet_priv *priv = netdev_priv(dev);
640 	struct device_node *dn = priv->pdev->dev.of_node;
641 
642 	if (of_phy_is_fixed_link(dn))
643 		of_phy_deregister_fixed_link(dn);
644 	of_node_put(priv->phy_dn);
645 	mdiobus_unregister(priv->mii_bus);
646 	mdiobus_free(priv->mii_bus);
647 }
648