xref: /linux/drivers/net/dsa/mv88e6xxx/pcs-639x.c (revision 0ad9617c78acbc71373fb341a6f75d4012b01d69)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Marvell 88E6352 family SERDES PCS support
4  *
5  * Copyright (c) 2008 Marvell Semiconductor
6  *
7  * Copyright (c) 2017 Andrew Lunn <andrew@lunn.ch>
8  */
9 #include <linux/interrupt.h>
10 #include <linux/irqdomain.h>
11 #include <linux/mii.h>
12 #include <linux/string_choices.h>
13 
14 #include "chip.h"
15 #include "global2.h"
16 #include "phy.h"
17 #include "port.h"
18 #include "serdes.h"
19 
20 struct mv88e639x_pcs {
21 	struct mdio_device mdio;
22 	struct phylink_pcs sgmii_pcs;
23 	struct phylink_pcs xg_pcs;
24 	bool erratum_3_14;
25 	bool supports_5g;
26 	phy_interface_t interface;
27 	unsigned int irq;
28 	char name[64];
29 	irqreturn_t (*handle_irq)(struct mv88e639x_pcs *mpcs);
30 };
31 
32 static int mv88e639x_read(struct mv88e639x_pcs *mpcs, u16 regnum, u16 *val)
33 {
34 	int err;
35 
36 	err = mdiodev_c45_read(&mpcs->mdio, MDIO_MMD_PHYXS, regnum);
37 	if (err < 0)
38 		return err;
39 
40 	*val = err;
41 
42 	return 0;
43 }
44 
45 static int mv88e639x_write(struct mv88e639x_pcs *mpcs, u16 regnum, u16 val)
46 {
47 	return mdiodev_c45_write(&mpcs->mdio, MDIO_MMD_PHYXS, regnum, val);
48 }
49 
50 static int mv88e639x_modify(struct mv88e639x_pcs *mpcs, u16 regnum, u16 mask,
51 			    u16 val)
52 {
53 	return mdiodev_c45_modify(&mpcs->mdio, MDIO_MMD_PHYXS, regnum, mask,
54 				  val);
55 }
56 
57 static int mv88e639x_modify_changed(struct mv88e639x_pcs *mpcs, u16 regnum,
58 				    u16 mask, u16 set)
59 {
60 	return mdiodev_c45_modify_changed(&mpcs->mdio, MDIO_MMD_PHYXS, regnum,
61 					  mask, set);
62 }
63 
64 static struct mv88e639x_pcs *
65 mv88e639x_pcs_alloc(struct device *dev, struct mii_bus *bus, unsigned int addr,
66 		    int port)
67 {
68 	struct mv88e639x_pcs *mpcs;
69 
70 	mpcs = kzalloc(sizeof(*mpcs), GFP_KERNEL);
71 	if (!mpcs)
72 		return NULL;
73 
74 	mpcs->mdio.dev.parent = dev;
75 	mpcs->mdio.bus = bus;
76 	mpcs->mdio.addr = addr;
77 
78 	snprintf(mpcs->name, sizeof(mpcs->name),
79 		 "mv88e6xxx-%s-serdes-%d", dev_name(dev), port);
80 
81 	return mpcs;
82 }
83 
84 static irqreturn_t mv88e639x_pcs_handle_irq(int irq, void *dev_id)
85 {
86 	struct mv88e639x_pcs *mpcs = dev_id;
87 	irqreturn_t (*handler)(struct mv88e639x_pcs *);
88 
89 	handler = READ_ONCE(mpcs->handle_irq);
90 	if (!handler)
91 		return IRQ_NONE;
92 
93 	return handler(mpcs);
94 }
95 
96 static int mv88e639x_pcs_setup_irq(struct mv88e639x_pcs *mpcs,
97 				   struct mv88e6xxx_chip *chip, int port)
98 {
99 	unsigned int irq;
100 
101 	irq = mv88e6xxx_serdes_irq_mapping(chip, port);
102 	if (!irq) {
103 		/* Use polling mode */
104 		mpcs->sgmii_pcs.poll = true;
105 		mpcs->xg_pcs.poll = true;
106 		return 0;
107 	}
108 
109 	mpcs->irq = irq;
110 
111 	return request_threaded_irq(irq, NULL, mv88e639x_pcs_handle_irq,
112 				    IRQF_ONESHOT, mpcs->name, mpcs);
113 }
114 
115 static void mv88e639x_pcs_teardown(struct mv88e6xxx_chip *chip, int port)
116 {
117 	struct mv88e639x_pcs *mpcs = chip->ports[port].pcs_private;
118 
119 	if (!mpcs)
120 		return;
121 
122 	if (mpcs->irq)
123 		free_irq(mpcs->irq, mpcs);
124 
125 	kfree(mpcs);
126 
127 	chip->ports[port].pcs_private = NULL;
128 }
129 
130 static struct mv88e639x_pcs *sgmii_pcs_to_mv88e639x_pcs(struct phylink_pcs *pcs)
131 {
132 	return container_of(pcs, struct mv88e639x_pcs, sgmii_pcs);
133 }
134 
135 static irqreturn_t mv88e639x_sgmii_handle_irq(struct mv88e639x_pcs *mpcs)
136 {
137 	u16 int_status;
138 	int err;
139 
140 	err = mv88e639x_read(mpcs, MV88E6390_SGMII_INT_STATUS, &int_status);
141 	if (err)
142 		return IRQ_NONE;
143 
144 	if (int_status & (MV88E6390_SGMII_INT_LINK_DOWN |
145 			  MV88E6390_SGMII_INT_LINK_UP)) {
146 		phylink_pcs_change(&mpcs->sgmii_pcs,
147 				   int_status & MV88E6390_SGMII_INT_LINK_UP);
148 
149 		return IRQ_HANDLED;
150 	}
151 
152 	return IRQ_NONE;
153 }
154 
155 static int mv88e639x_sgmii_pcs_control_irq(struct mv88e639x_pcs *mpcs,
156 					   bool enable)
157 {
158 	u16 val = 0;
159 
160 	if (enable)
161 		val |= MV88E6390_SGMII_INT_LINK_DOWN |
162 		       MV88E6390_SGMII_INT_LINK_UP;
163 
164 	return mv88e639x_modify(mpcs, MV88E6390_SGMII_INT_ENABLE,
165 				MV88E6390_SGMII_INT_LINK_DOWN |
166 				MV88E6390_SGMII_INT_LINK_UP, val);
167 }
168 
169 static int mv88e639x_sgmii_pcs_control_pwr(struct mv88e639x_pcs *mpcs,
170 					   bool enable)
171 {
172 	u16 mask, val;
173 
174 	if (enable) {
175 		mask = BMCR_RESET | BMCR_LOOPBACK | BMCR_PDOWN;
176 		val = 0;
177 	} else {
178 		mask = val = BMCR_PDOWN;
179 	}
180 
181 	return mv88e639x_modify(mpcs, MV88E6390_SGMII_BMCR, mask, val);
182 }
183 
184 static int mv88e639x_sgmii_pcs_enable(struct phylink_pcs *pcs)
185 {
186 	struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);
187 
188 	/* power enable done in post_config */
189 	mpcs->handle_irq = mv88e639x_sgmii_handle_irq;
190 
191 	return mv88e639x_sgmii_pcs_control_irq(mpcs, !!mpcs->irq);
192 }
193 
194 static void mv88e639x_sgmii_pcs_disable(struct phylink_pcs *pcs)
195 {
196 	struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);
197 
198 	mv88e639x_sgmii_pcs_control_irq(mpcs, false);
199 	mv88e639x_sgmii_pcs_control_pwr(mpcs, false);
200 }
201 
202 static void mv88e639x_sgmii_pcs_pre_config(struct phylink_pcs *pcs,
203 					   phy_interface_t interface)
204 {
205 	struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);
206 
207 	mv88e639x_sgmii_pcs_control_pwr(mpcs, false);
208 }
209 
210 static int mv88e6390_erratum_3_14(struct mv88e639x_pcs *mpcs)
211 {
212 	static const int lanes[] = { MV88E6390_PORT9_LANE0, MV88E6390_PORT9_LANE1,
213 		MV88E6390_PORT9_LANE2, MV88E6390_PORT9_LANE3,
214 		MV88E6390_PORT10_LANE0, MV88E6390_PORT10_LANE1,
215 		MV88E6390_PORT10_LANE2, MV88E6390_PORT10_LANE3 };
216 	int err, i;
217 
218 	/* 88e6190x and 88e6390x errata 3.14:
219 	 * After chip reset, SERDES reconfiguration or SERDES core
220 	 * Software Reset, the SERDES lanes may not be properly aligned
221 	 * resulting in CRC errors
222 	 */
223 
224 	for (i = 0; i < ARRAY_SIZE(lanes); i++) {
225 		err = mdiobus_c45_write(mpcs->mdio.bus, lanes[i],
226 					MDIO_MMD_PHYXS,
227 					0xf054, 0x400C);
228 		if (err)
229 			return err;
230 
231 		err = mdiobus_c45_write(mpcs->mdio.bus, lanes[i],
232 					MDIO_MMD_PHYXS,
233 					0xf054, 0x4000);
234 		if (err)
235 			return err;
236 	}
237 
238 	return 0;
239 }
240 
241 static int mv88e639x_sgmii_pcs_post_config(struct phylink_pcs *pcs,
242 					   phy_interface_t interface)
243 {
244 	struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);
245 	int err;
246 
247 	mv88e639x_sgmii_pcs_control_pwr(mpcs, true);
248 
249 	if (mpcs->erratum_3_14) {
250 		err = mv88e6390_erratum_3_14(mpcs);
251 		if (err)
252 			dev_err(mpcs->mdio.dev.parent,
253 				"failed to apply erratum 3.14: %pe\n",
254 				ERR_PTR(err));
255 	}
256 
257 	return 0;
258 }
259 
260 static void mv88e639x_sgmii_pcs_get_state(struct phylink_pcs *pcs,
261 					  unsigned int neg_mode,
262 					  struct phylink_link_state *state)
263 {
264 	struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);
265 	u16 bmsr, lpa, status;
266 	int err;
267 
268 	err = mv88e639x_read(mpcs, MV88E6390_SGMII_BMSR, &bmsr);
269 	if (err) {
270 		dev_err(mpcs->mdio.dev.parent,
271 			"can't read Serdes PHY %s: %pe\n",
272 			"BMSR", ERR_PTR(err));
273 		state->link = false;
274 		return;
275 	}
276 
277 	err = mv88e639x_read(mpcs, MV88E6390_SGMII_LPA, &lpa);
278 	if (err) {
279 		dev_err(mpcs->mdio.dev.parent,
280 			"can't read Serdes PHY %s: %pe\n",
281 			"LPA", ERR_PTR(err));
282 		state->link = false;
283 		return;
284 	}
285 
286 	err = mv88e639x_read(mpcs, MV88E6390_SGMII_PHY_STATUS, &status);
287 	if (err) {
288 		dev_err(mpcs->mdio.dev.parent,
289 			"can't read Serdes PHY %s: %pe\n",
290 			"status", ERR_PTR(err));
291 		state->link = false;
292 		return;
293 	}
294 
295 	mv88e6xxx_pcs_decode_state(mpcs->mdio.dev.parent, bmsr, lpa, status,
296 				   state);
297 }
298 
299 static int mv88e639x_sgmii_pcs_config(struct phylink_pcs *pcs,
300 				      unsigned int neg_mode,
301 				      phy_interface_t interface,
302 				      const unsigned long *advertising,
303 				      bool permit_pause_to_mac)
304 {
305 	struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);
306 	u16 val, bmcr;
307 	bool changed;
308 	int adv, err;
309 
310 	adv = phylink_mii_c22_pcs_encode_advertisement(interface, advertising);
311 	if (adv < 0)
312 		return 0;
313 
314 	mpcs->interface = interface;
315 
316 	err = mv88e639x_modify_changed(mpcs, MV88E6390_SGMII_ADVERTISE,
317 				       0xffff, adv);
318 	if (err < 0)
319 		return err;
320 
321 	changed = err > 0;
322 
323 	err = mv88e639x_read(mpcs, MV88E6390_SGMII_BMCR, &val);
324 	if (err)
325 		return err;
326 
327 	if (neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED)
328 		bmcr = val | BMCR_ANENABLE;
329 	else
330 		bmcr = val & ~BMCR_ANENABLE;
331 
332 	/* setting ANENABLE triggers a restart of negotiation */
333 	if (bmcr == val)
334 		return changed;
335 
336 	return mv88e639x_write(mpcs, MV88E6390_SGMII_BMCR, bmcr);
337 }
338 
339 static void mv88e639x_sgmii_pcs_an_restart(struct phylink_pcs *pcs)
340 {
341 	struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);
342 
343 	mv88e639x_modify(mpcs, MV88E6390_SGMII_BMCR,
344 			 BMCR_ANRESTART, BMCR_ANRESTART);
345 }
346 
347 static void mv88e639x_sgmii_pcs_link_up(struct phylink_pcs *pcs,
348 					unsigned int mode,
349 					phy_interface_t interface,
350 					int speed, int duplex)
351 {
352 	struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);
353 	u16 bmcr;
354 	int err;
355 
356 	if (phylink_autoneg_inband(mode))
357 		return;
358 
359 	bmcr = mii_bmcr_encode_fixed(speed, duplex);
360 
361 	err = mv88e639x_modify(mpcs, MV88E6390_SGMII_BMCR,
362 			       BMCR_SPEED1000 | BMCR_SPEED100 | BMCR_FULLDPLX,
363 			       bmcr);
364 	if (err)
365 		dev_err(mpcs->mdio.dev.parent,
366 			"can't access Serdes PHY %s: %pe\n",
367 			"BMCR", ERR_PTR(err));
368 }
369 
370 static const struct phylink_pcs_ops mv88e639x_sgmii_pcs_ops = {
371 	.pcs_enable = mv88e639x_sgmii_pcs_enable,
372 	.pcs_disable = mv88e639x_sgmii_pcs_disable,
373 	.pcs_pre_config = mv88e639x_sgmii_pcs_pre_config,
374 	.pcs_post_config = mv88e639x_sgmii_pcs_post_config,
375 	.pcs_get_state = mv88e639x_sgmii_pcs_get_state,
376 	.pcs_an_restart = mv88e639x_sgmii_pcs_an_restart,
377 	.pcs_config = mv88e639x_sgmii_pcs_config,
378 	.pcs_link_up = mv88e639x_sgmii_pcs_link_up,
379 };
380 
381 static struct mv88e639x_pcs *xg_pcs_to_mv88e639x_pcs(struct phylink_pcs *pcs)
382 {
383 	return container_of(pcs, struct mv88e639x_pcs, xg_pcs);
384 }
385 
386 static int mv88e639x_xg_pcs_enable(struct mv88e639x_pcs *mpcs)
387 {
388 	return mv88e639x_modify(mpcs, MV88E6390_10G_CTRL1,
389 				MDIO_CTRL1_RESET | MDIO_PCS_CTRL1_LOOPBACK |
390 				MDIO_CTRL1_LPOWER, 0);
391 }
392 
393 static void mv88e639x_xg_pcs_disable(struct mv88e639x_pcs *mpcs)
394 {
395 	mv88e639x_modify(mpcs, MV88E6390_10G_CTRL1, MDIO_CTRL1_LPOWER,
396 			 MDIO_CTRL1_LPOWER);
397 }
398 
399 static void mv88e639x_xg_pcs_get_state(struct phylink_pcs *pcs,
400 				       unsigned int neg_mode,
401 				       struct phylink_link_state *state)
402 {
403 	struct mv88e639x_pcs *mpcs = xg_pcs_to_mv88e639x_pcs(pcs);
404 	u16 status;
405 	int err;
406 
407 	state->link = false;
408 
409 	err = mv88e639x_read(mpcs, MV88E6390_10G_STAT1, &status);
410 	if (err) {
411 		dev_err(mpcs->mdio.dev.parent,
412 			"can't read Serdes PHY %s: %pe\n",
413 			"STAT1", ERR_PTR(err));
414 		return;
415 	}
416 
417 	state->link = !!(status & MDIO_STAT1_LSTATUS);
418 	if (state->link) {
419 		switch (state->interface) {
420 		case PHY_INTERFACE_MODE_5GBASER:
421 			state->speed = SPEED_5000;
422 			break;
423 
424 		case PHY_INTERFACE_MODE_10GBASER:
425 		case PHY_INTERFACE_MODE_RXAUI:
426 		case PHY_INTERFACE_MODE_XAUI:
427 			state->speed = SPEED_10000;
428 			break;
429 
430 		default:
431 			state->link = false;
432 			return;
433 		}
434 
435 		state->duplex = DUPLEX_FULL;
436 	}
437 }
438 
439 static int mv88e639x_xg_pcs_config(struct phylink_pcs *pcs,
440 				   unsigned int neg_mode,
441 				   phy_interface_t interface,
442 				   const unsigned long *advertising,
443 				   bool permit_pause_to_mac)
444 {
445 	return 0;
446 }
447 
448 static struct phylink_pcs *
449 mv88e639x_pcs_select(struct mv88e6xxx_chip *chip, int port,
450 		     phy_interface_t mode)
451 {
452 	struct mv88e639x_pcs *mpcs;
453 
454 	mpcs = chip->ports[port].pcs_private;
455 	if (!mpcs)
456 		return NULL;
457 
458 	switch (mode) {
459 	case PHY_INTERFACE_MODE_SGMII:
460 	case PHY_INTERFACE_MODE_1000BASEX:
461 	case PHY_INTERFACE_MODE_2500BASEX:
462 		return &mpcs->sgmii_pcs;
463 
464 	case PHY_INTERFACE_MODE_5GBASER:
465 		if (!mpcs->supports_5g)
466 			return NULL;
467 		fallthrough;
468 	case PHY_INTERFACE_MODE_10GBASER:
469 	case PHY_INTERFACE_MODE_XAUI:
470 	case PHY_INTERFACE_MODE_RXAUI:
471 	case PHY_INTERFACE_MODE_USXGMII:
472 		return &mpcs->xg_pcs;
473 
474 	default:
475 		return NULL;
476 	}
477 }
478 
479 /* Marvell 88E6390 Specific support */
480 
481 static irqreturn_t mv88e6390_xg_handle_irq(struct mv88e639x_pcs *mpcs)
482 {
483 	u16 int_status;
484 	int err;
485 
486 	err = mv88e639x_read(mpcs, MV88E6390_10G_INT_STATUS, &int_status);
487 	if (err)
488 		return IRQ_NONE;
489 
490 	if (int_status & (MV88E6390_10G_INT_LINK_DOWN |
491 			  MV88E6390_10G_INT_LINK_UP)) {
492 		phylink_pcs_change(&mpcs->xg_pcs,
493 				   int_status & MV88E6390_10G_INT_LINK_UP);
494 
495 		return IRQ_HANDLED;
496 	}
497 
498 	return IRQ_NONE;
499 }
500 
501 static int mv88e6390_xg_control_irq(struct mv88e639x_pcs *mpcs, bool enable)
502 {
503 	u16 val = 0;
504 
505 	if (enable)
506 		val = MV88E6390_10G_INT_LINK_DOWN | MV88E6390_10G_INT_LINK_UP;
507 
508 	return mv88e639x_modify(mpcs, MV88E6390_10G_INT_ENABLE,
509 				MV88E6390_10G_INT_LINK_DOWN |
510 				MV88E6390_10G_INT_LINK_UP, val);
511 }
512 
513 static int mv88e6390_xg_pcs_enable(struct phylink_pcs *pcs)
514 {
515 	struct mv88e639x_pcs *mpcs = xg_pcs_to_mv88e639x_pcs(pcs);
516 	int err;
517 
518 	err = mv88e639x_xg_pcs_enable(mpcs);
519 	if (err)
520 		return err;
521 
522 	mpcs->handle_irq = mv88e6390_xg_handle_irq;
523 
524 	return mv88e6390_xg_control_irq(mpcs, !!mpcs->irq);
525 }
526 
527 static void mv88e6390_xg_pcs_disable(struct phylink_pcs *pcs)
528 {
529 	struct mv88e639x_pcs *mpcs = xg_pcs_to_mv88e639x_pcs(pcs);
530 
531 	mv88e6390_xg_control_irq(mpcs, false);
532 	mv88e639x_xg_pcs_disable(mpcs);
533 }
534 
535 static const struct phylink_pcs_ops mv88e6390_xg_pcs_ops = {
536 	.pcs_enable = mv88e6390_xg_pcs_enable,
537 	.pcs_disable = mv88e6390_xg_pcs_disable,
538 	.pcs_get_state = mv88e639x_xg_pcs_get_state,
539 	.pcs_config = mv88e639x_xg_pcs_config,
540 };
541 
542 static int mv88e6390_pcs_enable_checker(struct mv88e639x_pcs *mpcs)
543 {
544 	return mv88e639x_modify(mpcs, MV88E6390_PG_CONTROL,
545 				MV88E6390_PG_CONTROL_ENABLE_PC,
546 				MV88E6390_PG_CONTROL_ENABLE_PC);
547 }
548 
549 static int mv88e6390_pcs_init(struct mv88e6xxx_chip *chip, int port)
550 {
551 	struct mv88e639x_pcs *mpcs;
552 	struct mii_bus *bus;
553 	struct device *dev;
554 	int lane, err;
555 
556 	lane = mv88e6xxx_serdes_get_lane(chip, port);
557 	if (lane < 0)
558 		return 0;
559 
560 	bus = mv88e6xxx_default_mdio_bus(chip);
561 	dev = chip->dev;
562 
563 	mpcs = mv88e639x_pcs_alloc(dev, bus, lane, port);
564 	if (!mpcs)
565 		return -ENOMEM;
566 
567 	mpcs->sgmii_pcs.ops = &mv88e639x_sgmii_pcs_ops;
568 	mpcs->sgmii_pcs.neg_mode = true;
569 	mpcs->xg_pcs.ops = &mv88e6390_xg_pcs_ops;
570 	mpcs->xg_pcs.neg_mode = true;
571 
572 	if (chip->info->prod_num == MV88E6XXX_PORT_SWITCH_ID_PROD_6190X ||
573 	    chip->info->prod_num == MV88E6XXX_PORT_SWITCH_ID_PROD_6390X)
574 		mpcs->erratum_3_14 = true;
575 
576 	err = mv88e639x_pcs_setup_irq(mpcs, chip, port);
577 	if (err)
578 		goto err_free;
579 
580 	/* 6390 and 6390x has the checker, 6393x doesn't appear to? */
581 	/* This is to enable gathering the statistics. Maybe this
582 	 * should call out to a helper? Or we could do this at init time.
583 	 */
584 	err = mv88e6390_pcs_enable_checker(mpcs);
585 	if (err)
586 		goto err_free;
587 
588 	chip->ports[port].pcs_private = mpcs;
589 
590 	return 0;
591 
592 err_free:
593 	kfree(mpcs);
594 	return err;
595 }
596 
597 const struct mv88e6xxx_pcs_ops mv88e6390_pcs_ops = {
598 	.pcs_init = mv88e6390_pcs_init,
599 	.pcs_teardown = mv88e639x_pcs_teardown,
600 	.pcs_select = mv88e639x_pcs_select,
601 };
602 
603 /* Marvell 88E6393X Specific support */
604 
605 static int mv88e6393x_power_lane(struct mv88e639x_pcs *mpcs, bool enable)
606 {
607 	u16 val = MV88E6393X_SERDES_CTRL1_TX_PDOWN |
608 		  MV88E6393X_SERDES_CTRL1_RX_PDOWN;
609 
610 	return mv88e639x_modify(mpcs, MV88E6393X_SERDES_CTRL1, val,
611 				enable ? 0 : val);
612 }
613 
614 /* mv88e6393x family errata 4.6:
615  * Cannot clear PwrDn bit on SERDES if device is configured CPU_MGD mode or
616  * P0_mode is configured for [x]MII.
617  * Workaround: Set SERDES register 4.F002 bit 5=0 and bit 15=1.
618  *
619  * It seems that after this workaround the SERDES is automatically powered up
620  * (the bit is cleared), so power it down.
621  */
622 static int mv88e6393x_erratum_4_6(struct mv88e639x_pcs *mpcs)
623 {
624 	int err;
625 
626 	err = mv88e639x_modify(mpcs, MV88E6393X_SERDES_POC,
627 			       MV88E6393X_SERDES_POC_PDOWN |
628 			       MV88E6393X_SERDES_POC_RESET,
629 			       MV88E6393X_SERDES_POC_RESET);
630 	if (err)
631 		return err;
632 
633 	err = mv88e639x_modify(mpcs, MV88E6390_SGMII_BMCR,
634 			       BMCR_PDOWN, BMCR_PDOWN);
635 	if (err)
636 		return err;
637 
638 	err = mv88e639x_sgmii_pcs_control_pwr(mpcs, false);
639 	if (err)
640 		return err;
641 
642 	return mv88e6393x_power_lane(mpcs, false);
643 }
644 
645 /* mv88e6393x family errata 4.8:
646  * When a SERDES port is operating in 1000BASE-X or SGMII mode link may not
647  * come up after hardware reset or software reset of SERDES core. Workaround
648  * is to write SERDES register 4.F074.14=1 for only those modes and 0 in all
649  * other modes.
650  */
651 static int mv88e6393x_erratum_4_8(struct mv88e639x_pcs *mpcs)
652 {
653 	u16 reg, poc;
654 	int err;
655 
656 	err = mv88e639x_read(mpcs, MV88E6393X_SERDES_POC, &poc);
657 	if (err)
658 		return err;
659 
660 	poc &= MV88E6393X_SERDES_POC_PCS_MASK;
661 	if (poc == MV88E6393X_SERDES_POC_PCS_1000BASEX ||
662 	    poc == MV88E6393X_SERDES_POC_PCS_SGMII_PHY ||
663 	    poc == MV88E6393X_SERDES_POC_PCS_SGMII_MAC)
664 		reg = MV88E6393X_ERRATA_4_8_BIT;
665 	else
666 		reg = 0;
667 
668 	return mv88e639x_modify(mpcs, MV88E6393X_ERRATA_4_8_REG,
669 				MV88E6393X_ERRATA_4_8_BIT, reg);
670 }
671 
672 /* mv88e6393x family errata 5.2:
673  * For optimal signal integrity the following sequence should be applied to
674  * SERDES operating in 10G mode. These registers only apply to 10G operation
675  * and have no effect on other speeds.
676  */
677 static int mv88e6393x_erratum_5_2(struct mv88e639x_pcs *mpcs)
678 {
679 	static const struct {
680 		u16 dev, reg, val, mask;
681 	} fixes[] = {
682 		{ MDIO_MMD_VEND1, 0x8093, 0xcb5a, 0xffff },
683 		{ MDIO_MMD_VEND1, 0x8171, 0x7088, 0xffff },
684 		{ MDIO_MMD_VEND1, 0x80c9, 0x311a, 0xffff },
685 		{ MDIO_MMD_VEND1, 0x80a2, 0x8000, 0xff7f },
686 		{ MDIO_MMD_VEND1, 0x80a9, 0x0000, 0xfff0 },
687 		{ MDIO_MMD_VEND1, 0x80a3, 0x0000, 0xf8ff },
688 		{ MDIO_MMD_PHYXS, MV88E6393X_SERDES_POC,
689 		  MV88E6393X_SERDES_POC_RESET, MV88E6393X_SERDES_POC_RESET },
690 	};
691 	int err, i;
692 
693 	for (i = 0; i < ARRAY_SIZE(fixes); ++i) {
694 		err = mdiodev_c45_modify(&mpcs->mdio, fixes[i].dev,
695 					 fixes[i].reg, fixes[i].mask,
696 					 fixes[i].val);
697 		if (err)
698 			return err;
699 	}
700 
701 	return 0;
702 }
703 
704 /* Inband AN is broken on Amethyst in 2500base-x mode when set by standard
705  * mechanism (via cmode).
706  * We can get around this by configuring the PCS mode to 1000base-x and then
707  * writing value 0x58 to register 1e.8000. (This must be done while SerDes
708  * receiver and transmitter are disabled, which is, when this function is
709  * called.)
710  * It seem that when we do this configuration to 2500base-x mode (by changing
711  * PCS mode to 1000base-x and frequency to 3.125 GHz from 1.25 GHz) and then
712  * configure to sgmii or 1000base-x, the device thinks that it already has
713  * SerDes at 1.25 GHz and does not change the 1e.8000 register, leaving SerDes
714  * at 3.125 GHz.
715  * To avoid this, change PCS mode back to 2500base-x when disabling SerDes from
716  * 2500base-x mode.
717  */
718 static int mv88e6393x_fix_2500basex_an(struct mv88e639x_pcs *mpcs, bool on)
719 {
720 	u16 reg;
721 	int err;
722 
723 	if (on)
724 		reg = MV88E6393X_SERDES_POC_PCS_1000BASEX |
725 		      MV88E6393X_SERDES_POC_AN;
726 	else
727 		reg = MV88E6393X_SERDES_POC_PCS_2500BASEX;
728 
729 	reg |= MV88E6393X_SERDES_POC_RESET;
730 
731 	err = mv88e639x_modify(mpcs, MV88E6393X_SERDES_POC,
732 			       MV88E6393X_SERDES_POC_PCS_MASK |
733 			       MV88E6393X_SERDES_POC_AN |
734 			       MV88E6393X_SERDES_POC_RESET, reg);
735 	if (err)
736 		return err;
737 
738 	return mdiodev_c45_write(&mpcs->mdio, MDIO_MMD_VEND1, 0x8000, 0x58);
739 }
740 
741 static int mv88e6393x_sgmii_apply_2500basex_an(struct mv88e639x_pcs *mpcs,
742 					       phy_interface_t interface,
743 					       bool enable)
744 {
745 	int err;
746 
747 	if (interface != PHY_INTERFACE_MODE_2500BASEX)
748 		return 0;
749 
750 	err = mv88e6393x_fix_2500basex_an(mpcs, enable);
751 	if (err)
752 		dev_err(mpcs->mdio.dev.parent,
753 			"failed to %s 2500basex fix: %pe\n",
754 			str_enable_disable(enable), ERR_PTR(err));
755 
756 	return err;
757 }
758 
759 static void mv88e6393x_sgmii_pcs_disable(struct phylink_pcs *pcs)
760 {
761 	struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);
762 
763 	mv88e639x_sgmii_pcs_disable(pcs);
764 	mv88e6393x_power_lane(mpcs, false);
765 	mv88e6393x_sgmii_apply_2500basex_an(mpcs, mpcs->interface, false);
766 }
767 
768 static void mv88e6393x_sgmii_pcs_pre_config(struct phylink_pcs *pcs,
769 					    phy_interface_t interface)
770 {
771 	struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);
772 
773 	mv88e639x_sgmii_pcs_pre_config(pcs, interface);
774 	mv88e6393x_power_lane(mpcs, false);
775 	mv88e6393x_sgmii_apply_2500basex_an(mpcs, mpcs->interface, false);
776 }
777 
778 static int mv88e6393x_sgmii_pcs_post_config(struct phylink_pcs *pcs,
779 					    phy_interface_t interface)
780 {
781 	struct mv88e639x_pcs *mpcs = sgmii_pcs_to_mv88e639x_pcs(pcs);
782 	int err;
783 
784 	err = mv88e6393x_erratum_4_8(mpcs);
785 	if (err)
786 		return err;
787 
788 	err = mv88e6393x_sgmii_apply_2500basex_an(mpcs, interface, true);
789 	if (err)
790 		return err;
791 
792 	err = mv88e6393x_power_lane(mpcs, true);
793 	if (err)
794 		return err;
795 
796 	return mv88e639x_sgmii_pcs_post_config(pcs, interface);
797 }
798 
799 static const struct phylink_pcs_ops mv88e6393x_sgmii_pcs_ops = {
800 	.pcs_enable = mv88e639x_sgmii_pcs_enable,
801 	.pcs_disable = mv88e6393x_sgmii_pcs_disable,
802 	.pcs_pre_config = mv88e6393x_sgmii_pcs_pre_config,
803 	.pcs_post_config = mv88e6393x_sgmii_pcs_post_config,
804 	.pcs_get_state = mv88e639x_sgmii_pcs_get_state,
805 	.pcs_an_restart = mv88e639x_sgmii_pcs_an_restart,
806 	.pcs_config = mv88e639x_sgmii_pcs_config,
807 	.pcs_link_up = mv88e639x_sgmii_pcs_link_up,
808 };
809 
810 static irqreturn_t mv88e6393x_xg_handle_irq(struct mv88e639x_pcs *mpcs)
811 {
812 	u16 int_status, stat1;
813 	bool link_down;
814 	int err;
815 
816 	err = mv88e639x_read(mpcs, MV88E6393X_10G_INT_STATUS, &int_status);
817 	if (err)
818 		return IRQ_NONE;
819 
820 	if (int_status & MV88E6393X_10G_INT_LINK_CHANGE) {
821 		err = mv88e639x_read(mpcs, MV88E6390_10G_STAT1, &stat1);
822 		if (err)
823 			return IRQ_NONE;
824 
825 		link_down = !(stat1 & MDIO_STAT1_LSTATUS);
826 
827 		phylink_pcs_change(&mpcs->xg_pcs, !link_down);
828 
829 		return IRQ_HANDLED;
830 	}
831 
832 	return IRQ_NONE;
833 }
834 
835 static int mv88e6393x_xg_control_irq(struct mv88e639x_pcs *mpcs, bool enable)
836 {
837 	u16 val = 0;
838 
839 	if (enable)
840 		val = MV88E6393X_10G_INT_LINK_CHANGE;
841 
842 	return mv88e639x_modify(mpcs, MV88E6393X_10G_INT_ENABLE,
843 				MV88E6393X_10G_INT_LINK_CHANGE, val);
844 }
845 
846 static int mv88e6393x_xg_pcs_enable(struct phylink_pcs *pcs)
847 {
848 	struct mv88e639x_pcs *mpcs = xg_pcs_to_mv88e639x_pcs(pcs);
849 
850 	mpcs->handle_irq = mv88e6393x_xg_handle_irq;
851 
852 	return mv88e6393x_xg_control_irq(mpcs, !!mpcs->irq);
853 }
854 
855 static void mv88e6393x_xg_pcs_disable(struct phylink_pcs *pcs)
856 {
857 	struct mv88e639x_pcs *mpcs = xg_pcs_to_mv88e639x_pcs(pcs);
858 
859 	mv88e6393x_xg_control_irq(mpcs, false);
860 	mv88e639x_xg_pcs_disable(mpcs);
861 	mv88e6393x_power_lane(mpcs, false);
862 }
863 
864 /* The PCS has to be powered down while CMODE is changed */
865 static void mv88e6393x_xg_pcs_pre_config(struct phylink_pcs *pcs,
866 					 phy_interface_t interface)
867 {
868 	struct mv88e639x_pcs *mpcs = xg_pcs_to_mv88e639x_pcs(pcs);
869 
870 	mv88e639x_xg_pcs_disable(mpcs);
871 	mv88e6393x_power_lane(mpcs, false);
872 }
873 
874 static int mv88e6393x_xg_pcs_post_config(struct phylink_pcs *pcs,
875 					 phy_interface_t interface)
876 {
877 	struct mv88e639x_pcs *mpcs = xg_pcs_to_mv88e639x_pcs(pcs);
878 	int err;
879 
880 	if (interface == PHY_INTERFACE_MODE_10GBASER ||
881 	    interface == PHY_INTERFACE_MODE_USXGMII) {
882 		err = mv88e6393x_erratum_5_2(mpcs);
883 		if (err)
884 			return err;
885 	}
886 
887 	err = mv88e6393x_power_lane(mpcs, true);
888 	if (err)
889 		return err;
890 
891 	return mv88e639x_xg_pcs_enable(mpcs);
892 }
893 
894 static void mv88e6393x_xg_pcs_get_state(struct phylink_pcs *pcs,
895 					unsigned int neg_mode,
896 					struct phylink_link_state *state)
897 {
898 	struct mv88e639x_pcs *mpcs = xg_pcs_to_mv88e639x_pcs(pcs);
899 	u16 status, lp_status;
900 	int err;
901 
902 	if (state->interface != PHY_INTERFACE_MODE_USXGMII)
903 		return mv88e639x_xg_pcs_get_state(pcs, neg_mode, state);
904 
905 	state->link = false;
906 
907 	err = mv88e639x_read(mpcs, MV88E6390_USXGMII_PHY_STATUS, &status);
908 	err = err ? : mv88e639x_read(mpcs, MV88E6390_USXGMII_LP_STATUS, &lp_status);
909 	if (err) {
910 		dev_err(mpcs->mdio.dev.parent,
911 			"can't read USXGMII status: %pe\n", ERR_PTR(err));
912 		return;
913 	}
914 
915 	state->link = !!(status & MDIO_USXGMII_LINK);
916 	state->an_complete = state->link;
917 	phylink_decode_usxgmii_word(state, lp_status);
918 }
919 
920 static const struct phylink_pcs_ops mv88e6393x_xg_pcs_ops = {
921 	.pcs_enable = mv88e6393x_xg_pcs_enable,
922 	.pcs_disable = mv88e6393x_xg_pcs_disable,
923 	.pcs_pre_config = mv88e6393x_xg_pcs_pre_config,
924 	.pcs_post_config = mv88e6393x_xg_pcs_post_config,
925 	.pcs_get_state = mv88e6393x_xg_pcs_get_state,
926 	.pcs_config = mv88e639x_xg_pcs_config,
927 };
928 
929 static int mv88e6393x_pcs_init(struct mv88e6xxx_chip *chip, int port)
930 {
931 	struct mv88e639x_pcs *mpcs;
932 	struct mii_bus *bus;
933 	struct device *dev;
934 	int lane, err;
935 
936 	lane = mv88e6xxx_serdes_get_lane(chip, port);
937 	if (lane < 0)
938 		return 0;
939 
940 	bus = mv88e6xxx_default_mdio_bus(chip);
941 	dev = chip->dev;
942 
943 	mpcs = mv88e639x_pcs_alloc(dev, bus, lane, port);
944 	if (!mpcs)
945 		return -ENOMEM;
946 
947 	mpcs->sgmii_pcs.ops = &mv88e6393x_sgmii_pcs_ops;
948 	mpcs->sgmii_pcs.neg_mode = true;
949 	mpcs->xg_pcs.ops = &mv88e6393x_xg_pcs_ops;
950 	mpcs->xg_pcs.neg_mode = true;
951 	mpcs->supports_5g = true;
952 
953 	err = mv88e6393x_erratum_4_6(mpcs);
954 	if (err)
955 		goto err_free;
956 
957 	err = mv88e639x_pcs_setup_irq(mpcs, chip, port);
958 	if (err)
959 		goto err_free;
960 
961 	chip->ports[port].pcs_private = mpcs;
962 
963 	return 0;
964 
965 err_free:
966 	kfree(mpcs);
967 	return err;
968 }
969 
970 const struct mv88e6xxx_pcs_ops mv88e6393x_pcs_ops = {
971 	.pcs_init = mv88e6393x_pcs_init,
972 	.pcs_teardown = mv88e639x_pcs_teardown,
973 	.pcs_select = mv88e639x_pcs_select,
974 };
975