xref: /linux/drivers/net/phy/sfp.c (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
1 #include <linux/delay.h>
2 #include <linux/gpio/consumer.h>
3 #include <linux/i2c.h>
4 #include <linux/interrupt.h>
5 #include <linux/jiffies.h>
6 #include <linux/module.h>
7 #include <linux/mutex.h>
8 #include <linux/of.h>
9 #include <linux/phy.h>
10 #include <linux/platform_device.h>
11 #include <linux/rtnetlink.h>
12 #include <linux/slab.h>
13 #include <linux/workqueue.h>
14 
15 #include "mdio-i2c.h"
16 #include "sfp.h"
17 #include "swphy.h"
18 
19 enum {
20 	GPIO_MODDEF0,
21 	GPIO_LOS,
22 	GPIO_TX_FAULT,
23 	GPIO_TX_DISABLE,
24 	GPIO_RATE_SELECT,
25 	GPIO_MAX,
26 
27 	SFP_F_PRESENT = BIT(GPIO_MODDEF0),
28 	SFP_F_LOS = BIT(GPIO_LOS),
29 	SFP_F_TX_FAULT = BIT(GPIO_TX_FAULT),
30 	SFP_F_TX_DISABLE = BIT(GPIO_TX_DISABLE),
31 	SFP_F_RATE_SELECT = BIT(GPIO_RATE_SELECT),
32 
33 	SFP_E_INSERT = 0,
34 	SFP_E_REMOVE,
35 	SFP_E_DEV_DOWN,
36 	SFP_E_DEV_UP,
37 	SFP_E_TX_FAULT,
38 	SFP_E_TX_CLEAR,
39 	SFP_E_LOS_HIGH,
40 	SFP_E_LOS_LOW,
41 	SFP_E_TIMEOUT,
42 
43 	SFP_MOD_EMPTY = 0,
44 	SFP_MOD_PROBE,
45 	SFP_MOD_PRESENT,
46 	SFP_MOD_ERROR,
47 
48 	SFP_DEV_DOWN = 0,
49 	SFP_DEV_UP,
50 
51 	SFP_S_DOWN = 0,
52 	SFP_S_INIT,
53 	SFP_S_WAIT_LOS,
54 	SFP_S_LINK_UP,
55 	SFP_S_TX_FAULT,
56 	SFP_S_REINIT,
57 	SFP_S_TX_DISABLE,
58 };
59 
60 static const char *gpio_of_names[] = {
61 	"mod-def0",
62 	"los",
63 	"tx-fault",
64 	"tx-disable",
65 	"rate-select0",
66 };
67 
68 static const enum gpiod_flags gpio_flags[] = {
69 	GPIOD_IN,
70 	GPIOD_IN,
71 	GPIOD_IN,
72 	GPIOD_ASIS,
73 	GPIOD_ASIS,
74 };
75 
76 #define T_INIT_JIFFIES	msecs_to_jiffies(300)
77 #define T_RESET_US	10
78 #define T_FAULT_RECOVER	msecs_to_jiffies(1000)
79 
80 /* SFP module presence detection is poor: the three MOD DEF signals are
81  * the same length on the PCB, which means it's possible for MOD DEF 0 to
82  * connect before the I2C bus on MOD DEF 1/2.
83  *
84  * The SFP MSA specifies 300ms as t_init (the time taken for TX_FAULT to
85  * be deasserted) but makes no mention of the earliest time before we can
86  * access the I2C EEPROM.  However, Avago modules require 300ms.
87  */
88 #define T_PROBE_INIT	msecs_to_jiffies(300)
89 #define T_PROBE_RETRY	msecs_to_jiffies(100)
90 
91 /* SFP modules appear to always have their PHY configured for bus address
92  * 0x56 (which with mdio-i2c, translates to a PHY address of 22).
93  */
94 #define SFP_PHY_ADDR	22
95 
96 /* Give this long for the PHY to reset. */
97 #define T_PHY_RESET_MS	50
98 
99 static DEFINE_MUTEX(sfp_mutex);
100 
101 struct sfp {
102 	struct device *dev;
103 	struct i2c_adapter *i2c;
104 	struct mii_bus *i2c_mii;
105 	struct sfp_bus *sfp_bus;
106 	struct phy_device *mod_phy;
107 
108 	unsigned int (*get_state)(struct sfp *);
109 	void (*set_state)(struct sfp *, unsigned int);
110 	int (*read)(struct sfp *, bool, u8, void *, size_t);
111 
112 	struct gpio_desc *gpio[GPIO_MAX];
113 
114 	unsigned int state;
115 	struct delayed_work poll;
116 	struct delayed_work timeout;
117 	struct mutex sm_mutex;
118 	unsigned char sm_mod_state;
119 	unsigned char sm_dev_state;
120 	unsigned short sm_state;
121 	unsigned int sm_retries;
122 
123 	struct sfp_eeprom_id id;
124 };
125 
126 static unsigned long poll_jiffies;
127 
128 static unsigned int sfp_gpio_get_state(struct sfp *sfp)
129 {
130 	unsigned int i, state, v;
131 
132 	for (i = state = 0; i < GPIO_MAX; i++) {
133 		if (gpio_flags[i] != GPIOD_IN || !sfp->gpio[i])
134 			continue;
135 
136 		v = gpiod_get_value_cansleep(sfp->gpio[i]);
137 		if (v)
138 			state |= BIT(i);
139 	}
140 
141 	return state;
142 }
143 
144 static void sfp_gpio_set_state(struct sfp *sfp, unsigned int state)
145 {
146 	if (state & SFP_F_PRESENT) {
147 		/* If the module is present, drive the signals */
148 		if (sfp->gpio[GPIO_TX_DISABLE])
149 			gpiod_direction_output(sfp->gpio[GPIO_TX_DISABLE],
150 					       state & SFP_F_TX_DISABLE);
151 		if (state & SFP_F_RATE_SELECT)
152 			gpiod_direction_output(sfp->gpio[GPIO_RATE_SELECT],
153 					       state & SFP_F_RATE_SELECT);
154 	} else {
155 		/* Otherwise, let them float to the pull-ups */
156 		if (sfp->gpio[GPIO_TX_DISABLE])
157 			gpiod_direction_input(sfp->gpio[GPIO_TX_DISABLE]);
158 		if (state & SFP_F_RATE_SELECT)
159 			gpiod_direction_input(sfp->gpio[GPIO_RATE_SELECT]);
160 	}
161 }
162 
163 static int sfp__i2c_read(struct i2c_adapter *i2c, u8 bus_addr, u8 dev_addr,
164 			 void *buf, size_t len)
165 {
166 	struct i2c_msg msgs[2];
167 	int ret;
168 
169 	msgs[0].addr = bus_addr;
170 	msgs[0].flags = 0;
171 	msgs[0].len = 1;
172 	msgs[0].buf = &dev_addr;
173 	msgs[1].addr = bus_addr;
174 	msgs[1].flags = I2C_M_RD;
175 	msgs[1].len = len;
176 	msgs[1].buf = buf;
177 
178 	ret = i2c_transfer(i2c, msgs, ARRAY_SIZE(msgs));
179 	if (ret < 0)
180 		return ret;
181 
182 	return ret == ARRAY_SIZE(msgs) ? len : 0;
183 }
184 
185 static int sfp_i2c_read(struct sfp *sfp, bool a2, u8 addr, void *buf,
186 			size_t len)
187 {
188 	return sfp__i2c_read(sfp->i2c, a2 ? 0x51 : 0x50, addr, buf, len);
189 }
190 
191 static int sfp_i2c_configure(struct sfp *sfp, struct i2c_adapter *i2c)
192 {
193 	struct mii_bus *i2c_mii;
194 	int ret;
195 
196 	if (!i2c_check_functionality(i2c, I2C_FUNC_I2C))
197 		return -EINVAL;
198 
199 	sfp->i2c = i2c;
200 	sfp->read = sfp_i2c_read;
201 
202 	i2c_mii = mdio_i2c_alloc(sfp->dev, i2c);
203 	if (IS_ERR(i2c_mii))
204 		return PTR_ERR(i2c_mii);
205 
206 	i2c_mii->name = "SFP I2C Bus";
207 	i2c_mii->phy_mask = ~0;
208 
209 	ret = mdiobus_register(i2c_mii);
210 	if (ret < 0) {
211 		mdiobus_free(i2c_mii);
212 		return ret;
213 	}
214 
215 	sfp->i2c_mii = i2c_mii;
216 
217 	return 0;
218 }
219 
220 /* Interface */
221 static unsigned int sfp_get_state(struct sfp *sfp)
222 {
223 	return sfp->get_state(sfp);
224 }
225 
226 static void sfp_set_state(struct sfp *sfp, unsigned int state)
227 {
228 	sfp->set_state(sfp, state);
229 }
230 
231 static int sfp_read(struct sfp *sfp, bool a2, u8 addr, void *buf, size_t len)
232 {
233 	return sfp->read(sfp, a2, addr, buf, len);
234 }
235 
236 static unsigned int sfp_check(void *buf, size_t len)
237 {
238 	u8 *p, check;
239 
240 	for (p = buf, check = 0; len; p++, len--)
241 		check += *p;
242 
243 	return check;
244 }
245 
246 /* Helpers */
247 static void sfp_module_tx_disable(struct sfp *sfp)
248 {
249 	dev_dbg(sfp->dev, "tx disable %u -> %u\n",
250 		sfp->state & SFP_F_TX_DISABLE ? 1 : 0, 1);
251 	sfp->state |= SFP_F_TX_DISABLE;
252 	sfp_set_state(sfp, sfp->state);
253 }
254 
255 static void sfp_module_tx_enable(struct sfp *sfp)
256 {
257 	dev_dbg(sfp->dev, "tx disable %u -> %u\n",
258 		sfp->state & SFP_F_TX_DISABLE ? 1 : 0, 0);
259 	sfp->state &= ~SFP_F_TX_DISABLE;
260 	sfp_set_state(sfp, sfp->state);
261 }
262 
263 static void sfp_module_tx_fault_reset(struct sfp *sfp)
264 {
265 	unsigned int state = sfp->state;
266 
267 	if (state & SFP_F_TX_DISABLE)
268 		return;
269 
270 	sfp_set_state(sfp, state | SFP_F_TX_DISABLE);
271 
272 	udelay(T_RESET_US);
273 
274 	sfp_set_state(sfp, state);
275 }
276 
277 /* SFP state machine */
278 static void sfp_sm_set_timer(struct sfp *sfp, unsigned int timeout)
279 {
280 	if (timeout)
281 		mod_delayed_work(system_power_efficient_wq, &sfp->timeout,
282 				 timeout);
283 	else
284 		cancel_delayed_work(&sfp->timeout);
285 }
286 
287 static void sfp_sm_next(struct sfp *sfp, unsigned int state,
288 			unsigned int timeout)
289 {
290 	sfp->sm_state = state;
291 	sfp_sm_set_timer(sfp, timeout);
292 }
293 
294 static void sfp_sm_ins_next(struct sfp *sfp, unsigned int state,
295 			    unsigned int timeout)
296 {
297 	sfp->sm_mod_state = state;
298 	sfp_sm_set_timer(sfp, timeout);
299 }
300 
301 static void sfp_sm_phy_detach(struct sfp *sfp)
302 {
303 	phy_stop(sfp->mod_phy);
304 	sfp_remove_phy(sfp->sfp_bus);
305 	phy_device_remove(sfp->mod_phy);
306 	phy_device_free(sfp->mod_phy);
307 	sfp->mod_phy = NULL;
308 }
309 
310 static void sfp_sm_probe_phy(struct sfp *sfp)
311 {
312 	struct phy_device *phy;
313 	int err;
314 
315 	msleep(T_PHY_RESET_MS);
316 
317 	phy = mdiobus_scan(sfp->i2c_mii, SFP_PHY_ADDR);
318 	if (IS_ERR(phy)) {
319 		dev_err(sfp->dev, "mdiobus scan returned %ld\n", PTR_ERR(phy));
320 		return;
321 	}
322 	if (!phy) {
323 		dev_info(sfp->dev, "no PHY detected\n");
324 		return;
325 	}
326 
327 	err = sfp_add_phy(sfp->sfp_bus, phy);
328 	if (err) {
329 		phy_device_remove(phy);
330 		phy_device_free(phy);
331 		dev_err(sfp->dev, "sfp_add_phy failed: %d\n", err);
332 		return;
333 	}
334 
335 	sfp->mod_phy = phy;
336 	phy_start(phy);
337 }
338 
339 static void sfp_sm_link_up(struct sfp *sfp)
340 {
341 	sfp_link_up(sfp->sfp_bus);
342 	sfp_sm_next(sfp, SFP_S_LINK_UP, 0);
343 }
344 
345 static void sfp_sm_link_down(struct sfp *sfp)
346 {
347 	sfp_link_down(sfp->sfp_bus);
348 }
349 
350 static void sfp_sm_link_check_los(struct sfp *sfp)
351 {
352 	unsigned int los = sfp->state & SFP_F_LOS;
353 
354 	/* If neither SFP_OPTIONS_LOS_INVERTED nor SFP_OPTIONS_LOS_NORMAL
355 	 * are set, we assume that no LOS signal is available.
356 	 */
357 	if (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_INVERTED))
358 		los ^= SFP_F_LOS;
359 	else if (!(sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_NORMAL)))
360 		los = 0;
361 
362 	if (los)
363 		sfp_sm_next(sfp, SFP_S_WAIT_LOS, 0);
364 	else
365 		sfp_sm_link_up(sfp);
366 }
367 
368 static bool sfp_los_event_active(struct sfp *sfp, unsigned int event)
369 {
370 	return (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_INVERTED) &&
371 		event == SFP_E_LOS_LOW) ||
372 	       (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_NORMAL) &&
373 		event == SFP_E_LOS_HIGH);
374 }
375 
376 static bool sfp_los_event_inactive(struct sfp *sfp, unsigned int event)
377 {
378 	return (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_INVERTED) &&
379 		event == SFP_E_LOS_HIGH) ||
380 	       (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_NORMAL) &&
381 		event == SFP_E_LOS_LOW);
382 }
383 
384 static void sfp_sm_fault(struct sfp *sfp, bool warn)
385 {
386 	if (sfp->sm_retries && !--sfp->sm_retries) {
387 		dev_err(sfp->dev,
388 			"module persistently indicates fault, disabling\n");
389 		sfp_sm_next(sfp, SFP_S_TX_DISABLE, 0);
390 	} else {
391 		if (warn)
392 			dev_err(sfp->dev, "module transmit fault indicated\n");
393 
394 		sfp_sm_next(sfp, SFP_S_TX_FAULT, T_FAULT_RECOVER);
395 	}
396 }
397 
398 static void sfp_sm_mod_init(struct sfp *sfp)
399 {
400 	sfp_module_tx_enable(sfp);
401 
402 	/* Wait t_init before indicating that the link is up, provided the
403 	 * current state indicates no TX_FAULT.  If TX_FAULT clears before
404 	 * this time, that's fine too.
405 	 */
406 	sfp_sm_next(sfp, SFP_S_INIT, T_INIT_JIFFIES);
407 	sfp->sm_retries = 5;
408 
409 	/* Setting the serdes link mode is guesswork: there's no
410 	 * field in the EEPROM which indicates what mode should
411 	 * be used.
412 	 *
413 	 * If it's a gigabit-only fiber module, it probably does
414 	 * not have a PHY, so switch to 802.3z negotiation mode.
415 	 * Otherwise, switch to SGMII mode (which is required to
416 	 * support non-gigabit speeds) and probe for a PHY.
417 	 */
418 	if (sfp->id.base.e1000_base_t ||
419 	    sfp->id.base.e100_base_lx ||
420 	    sfp->id.base.e100_base_fx)
421 		sfp_sm_probe_phy(sfp);
422 }
423 
424 static int sfp_sm_mod_probe(struct sfp *sfp)
425 {
426 	/* SFP module inserted - read I2C data */
427 	struct sfp_eeprom_id id;
428 	char vendor[17];
429 	char part[17];
430 	char sn[17];
431 	char date[9];
432 	char rev[5];
433 	u8 check;
434 	int err;
435 
436 	err = sfp_read(sfp, false, 0, &id, sizeof(id));
437 	if (err < 0) {
438 		dev_err(sfp->dev, "failed to read EEPROM: %d\n", err);
439 		return -EAGAIN;
440 	}
441 
442 	if (err != sizeof(id)) {
443 		dev_err(sfp->dev, "EEPROM short read: %d\n", err);
444 		return -EAGAIN;
445 	}
446 
447 	/* Validate the checksum over the base structure */
448 	check = sfp_check(&id.base, sizeof(id.base) - 1);
449 	if (check != id.base.cc_base) {
450 		dev_err(sfp->dev,
451 			"EEPROM base structure checksum failure: 0x%02x\n",
452 			check);
453 		print_hex_dump(KERN_ERR, "sfp EE: ", DUMP_PREFIX_OFFSET,
454 			       16, 1, &id, sizeof(id.base) - 1, true);
455 		return -EINVAL;
456 	}
457 
458 	check = sfp_check(&id.ext, sizeof(id.ext) - 1);
459 	if (check != id.ext.cc_ext) {
460 		dev_err(sfp->dev,
461 			"EEPROM extended structure checksum failure: 0x%02x\n",
462 			check);
463 		memset(&id.ext, 0, sizeof(id.ext));
464 	}
465 
466 	sfp->id = id;
467 
468 	memcpy(vendor, sfp->id.base.vendor_name, 16);
469 	vendor[16] = '\0';
470 	memcpy(part, sfp->id.base.vendor_pn, 16);
471 	part[16] = '\0';
472 	memcpy(rev, sfp->id.base.vendor_rev, 4);
473 	rev[4] = '\0';
474 	memcpy(sn, sfp->id.ext.vendor_sn, 16);
475 	sn[16] = '\0';
476 	memcpy(date, sfp->id.ext.datecode, 8);
477 	date[8] = '\0';
478 
479 	dev_info(sfp->dev, "module %s %s rev %s sn %s dc %s\n",
480 		 vendor, part, rev, sn, date);
481 
482 	/* We only support SFP modules, not the legacy GBIC modules. */
483 	if (sfp->id.base.phys_id != SFP_PHYS_ID_SFP ||
484 	    sfp->id.base.phys_ext_id != SFP_PHYS_EXT_ID_SFP) {
485 		dev_err(sfp->dev, "module is not SFP - phys id 0x%02x 0x%02x\n",
486 			sfp->id.base.phys_id, sfp->id.base.phys_ext_id);
487 		return -EINVAL;
488 	}
489 
490 	/* If the module requires address swap mode, warn about it */
491 	if (sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE)
492 		dev_warn(sfp->dev,
493 			 "module address swap to access page 0xA2 is not supported.\n");
494 
495 	return sfp_module_insert(sfp->sfp_bus, &sfp->id);
496 }
497 
498 static void sfp_sm_mod_remove(struct sfp *sfp)
499 {
500 	sfp_module_remove(sfp->sfp_bus);
501 
502 	if (sfp->mod_phy)
503 		sfp_sm_phy_detach(sfp);
504 
505 	sfp_module_tx_disable(sfp);
506 
507 	memset(&sfp->id, 0, sizeof(sfp->id));
508 
509 	dev_info(sfp->dev, "module removed\n");
510 }
511 
512 static void sfp_sm_event(struct sfp *sfp, unsigned int event)
513 {
514 	mutex_lock(&sfp->sm_mutex);
515 
516 	dev_dbg(sfp->dev, "SM: enter %u:%u:%u event %u\n",
517 		sfp->sm_mod_state, sfp->sm_dev_state, sfp->sm_state, event);
518 
519 	/* This state machine tracks the insert/remove state of
520 	 * the module, and handles probing the on-board EEPROM.
521 	 */
522 	switch (sfp->sm_mod_state) {
523 	default:
524 		if (event == SFP_E_INSERT) {
525 			sfp_module_tx_disable(sfp);
526 			sfp_sm_ins_next(sfp, SFP_MOD_PROBE, T_PROBE_INIT);
527 		}
528 		break;
529 
530 	case SFP_MOD_PROBE:
531 		if (event == SFP_E_REMOVE) {
532 			sfp_sm_ins_next(sfp, SFP_MOD_EMPTY, 0);
533 		} else if (event == SFP_E_TIMEOUT) {
534 			int err = sfp_sm_mod_probe(sfp);
535 
536 			if (err == 0)
537 				sfp_sm_ins_next(sfp, SFP_MOD_PRESENT, 0);
538 			else if (err == -EAGAIN)
539 				sfp_sm_set_timer(sfp, T_PROBE_RETRY);
540 			else
541 				sfp_sm_ins_next(sfp, SFP_MOD_ERROR, 0);
542 		}
543 		break;
544 
545 	case SFP_MOD_PRESENT:
546 	case SFP_MOD_ERROR:
547 		if (event == SFP_E_REMOVE) {
548 			sfp_sm_mod_remove(sfp);
549 			sfp_sm_ins_next(sfp, SFP_MOD_EMPTY, 0);
550 		}
551 		break;
552 	}
553 
554 	/* This state machine tracks the netdev up/down state */
555 	switch (sfp->sm_dev_state) {
556 	default:
557 		if (event == SFP_E_DEV_UP)
558 			sfp->sm_dev_state = SFP_DEV_UP;
559 		break;
560 
561 	case SFP_DEV_UP:
562 		if (event == SFP_E_DEV_DOWN) {
563 			/* If the module has a PHY, avoid raising TX disable
564 			 * as this resets the PHY. Otherwise, raise it to
565 			 * turn the laser off.
566 			 */
567 			if (!sfp->mod_phy)
568 				sfp_module_tx_disable(sfp);
569 			sfp->sm_dev_state = SFP_DEV_DOWN;
570 		}
571 		break;
572 	}
573 
574 	/* Some events are global */
575 	if (sfp->sm_state != SFP_S_DOWN &&
576 	    (sfp->sm_mod_state != SFP_MOD_PRESENT ||
577 	     sfp->sm_dev_state != SFP_DEV_UP)) {
578 		if (sfp->sm_state == SFP_S_LINK_UP &&
579 		    sfp->sm_dev_state == SFP_DEV_UP)
580 			sfp_sm_link_down(sfp);
581 		if (sfp->mod_phy)
582 			sfp_sm_phy_detach(sfp);
583 		sfp_sm_next(sfp, SFP_S_DOWN, 0);
584 		mutex_unlock(&sfp->sm_mutex);
585 		return;
586 	}
587 
588 	/* The main state machine */
589 	switch (sfp->sm_state) {
590 	case SFP_S_DOWN:
591 		if (sfp->sm_mod_state == SFP_MOD_PRESENT &&
592 		    sfp->sm_dev_state == SFP_DEV_UP)
593 			sfp_sm_mod_init(sfp);
594 		break;
595 
596 	case SFP_S_INIT:
597 		if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT)
598 			sfp_sm_fault(sfp, true);
599 		else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR)
600 			sfp_sm_link_check_los(sfp);
601 		break;
602 
603 	case SFP_S_WAIT_LOS:
604 		if (event == SFP_E_TX_FAULT)
605 			sfp_sm_fault(sfp, true);
606 		else if (sfp_los_event_inactive(sfp, event))
607 			sfp_sm_link_up(sfp);
608 		break;
609 
610 	case SFP_S_LINK_UP:
611 		if (event == SFP_E_TX_FAULT) {
612 			sfp_sm_link_down(sfp);
613 			sfp_sm_fault(sfp, true);
614 		} else if (sfp_los_event_active(sfp, event)) {
615 			sfp_sm_link_down(sfp);
616 			sfp_sm_next(sfp, SFP_S_WAIT_LOS, 0);
617 		}
618 		break;
619 
620 	case SFP_S_TX_FAULT:
621 		if (event == SFP_E_TIMEOUT) {
622 			sfp_module_tx_fault_reset(sfp);
623 			sfp_sm_next(sfp, SFP_S_REINIT, T_INIT_JIFFIES);
624 		}
625 		break;
626 
627 	case SFP_S_REINIT:
628 		if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT) {
629 			sfp_sm_fault(sfp, false);
630 		} else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR) {
631 			dev_info(sfp->dev, "module transmit fault recovered\n");
632 			sfp_sm_link_check_los(sfp);
633 		}
634 		break;
635 
636 	case SFP_S_TX_DISABLE:
637 		break;
638 	}
639 
640 	dev_dbg(sfp->dev, "SM: exit %u:%u:%u\n",
641 		sfp->sm_mod_state, sfp->sm_dev_state, sfp->sm_state);
642 
643 	mutex_unlock(&sfp->sm_mutex);
644 }
645 
646 static void sfp_start(struct sfp *sfp)
647 {
648 	sfp_sm_event(sfp, SFP_E_DEV_UP);
649 }
650 
651 static void sfp_stop(struct sfp *sfp)
652 {
653 	sfp_sm_event(sfp, SFP_E_DEV_DOWN);
654 }
655 
656 static int sfp_module_info(struct sfp *sfp, struct ethtool_modinfo *modinfo)
657 {
658 	/* locking... and check module is present */
659 
660 	if (sfp->id.ext.sff8472_compliance &&
661 	    !(sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE)) {
662 		modinfo->type = ETH_MODULE_SFF_8472;
663 		modinfo->eeprom_len = ETH_MODULE_SFF_8472_LEN;
664 	} else {
665 		modinfo->type = ETH_MODULE_SFF_8079;
666 		modinfo->eeprom_len = ETH_MODULE_SFF_8079_LEN;
667 	}
668 	return 0;
669 }
670 
671 static int sfp_module_eeprom(struct sfp *sfp, struct ethtool_eeprom *ee,
672 			     u8 *data)
673 {
674 	unsigned int first, last, len;
675 	int ret;
676 
677 	if (ee->len == 0)
678 		return -EINVAL;
679 
680 	first = ee->offset;
681 	last = ee->offset + ee->len;
682 	if (first < ETH_MODULE_SFF_8079_LEN) {
683 		len = min_t(unsigned int, last, ETH_MODULE_SFF_8079_LEN);
684 		len -= first;
685 
686 		ret = sfp->read(sfp, false, first, data, len);
687 		if (ret < 0)
688 			return ret;
689 
690 		first += len;
691 		data += len;
692 	}
693 	if (first >= ETH_MODULE_SFF_8079_LEN &&
694 	    first < ETH_MODULE_SFF_8472_LEN) {
695 		len = min_t(unsigned int, last, ETH_MODULE_SFF_8472_LEN);
696 		len -= first;
697 		first -= ETH_MODULE_SFF_8079_LEN;
698 
699 		ret = sfp->read(sfp, true, first, data, len);
700 		if (ret < 0)
701 			return ret;
702 	}
703 	return 0;
704 }
705 
706 static const struct sfp_socket_ops sfp_module_ops = {
707 	.start = sfp_start,
708 	.stop = sfp_stop,
709 	.module_info = sfp_module_info,
710 	.module_eeprom = sfp_module_eeprom,
711 };
712 
713 static void sfp_timeout(struct work_struct *work)
714 {
715 	struct sfp *sfp = container_of(work, struct sfp, timeout.work);
716 
717 	rtnl_lock();
718 	sfp_sm_event(sfp, SFP_E_TIMEOUT);
719 	rtnl_unlock();
720 }
721 
722 static void sfp_check_state(struct sfp *sfp)
723 {
724 	unsigned int state, i, changed;
725 
726 	state = sfp_get_state(sfp);
727 	changed = state ^ sfp->state;
728 	changed &= SFP_F_PRESENT | SFP_F_LOS | SFP_F_TX_FAULT;
729 
730 	for (i = 0; i < GPIO_MAX; i++)
731 		if (changed & BIT(i))
732 			dev_dbg(sfp->dev, "%s %u -> %u\n", gpio_of_names[i],
733 				!!(sfp->state & BIT(i)), !!(state & BIT(i)));
734 
735 	state |= sfp->state & (SFP_F_TX_DISABLE | SFP_F_RATE_SELECT);
736 	sfp->state = state;
737 
738 	rtnl_lock();
739 	if (changed & SFP_F_PRESENT)
740 		sfp_sm_event(sfp, state & SFP_F_PRESENT ?
741 				SFP_E_INSERT : SFP_E_REMOVE);
742 
743 	if (changed & SFP_F_TX_FAULT)
744 		sfp_sm_event(sfp, state & SFP_F_TX_FAULT ?
745 				SFP_E_TX_FAULT : SFP_E_TX_CLEAR);
746 
747 	if (changed & SFP_F_LOS)
748 		sfp_sm_event(sfp, state & SFP_F_LOS ?
749 				SFP_E_LOS_HIGH : SFP_E_LOS_LOW);
750 	rtnl_unlock();
751 }
752 
753 static irqreturn_t sfp_irq(int irq, void *data)
754 {
755 	struct sfp *sfp = data;
756 
757 	sfp_check_state(sfp);
758 
759 	return IRQ_HANDLED;
760 }
761 
762 static void sfp_poll(struct work_struct *work)
763 {
764 	struct sfp *sfp = container_of(work, struct sfp, poll.work);
765 
766 	sfp_check_state(sfp);
767 	mod_delayed_work(system_wq, &sfp->poll, poll_jiffies);
768 }
769 
770 static struct sfp *sfp_alloc(struct device *dev)
771 {
772 	struct sfp *sfp;
773 
774 	sfp = kzalloc(sizeof(*sfp), GFP_KERNEL);
775 	if (!sfp)
776 		return ERR_PTR(-ENOMEM);
777 
778 	sfp->dev = dev;
779 
780 	mutex_init(&sfp->sm_mutex);
781 	INIT_DELAYED_WORK(&sfp->poll, sfp_poll);
782 	INIT_DELAYED_WORK(&sfp->timeout, sfp_timeout);
783 
784 	return sfp;
785 }
786 
787 static void sfp_cleanup(void *data)
788 {
789 	struct sfp *sfp = data;
790 
791 	cancel_delayed_work_sync(&sfp->poll);
792 	cancel_delayed_work_sync(&sfp->timeout);
793 	if (sfp->i2c_mii) {
794 		mdiobus_unregister(sfp->i2c_mii);
795 		mdiobus_free(sfp->i2c_mii);
796 	}
797 	if (sfp->i2c)
798 		i2c_put_adapter(sfp->i2c);
799 	kfree(sfp);
800 }
801 
802 static int sfp_probe(struct platform_device *pdev)
803 {
804 	struct sfp *sfp;
805 	bool poll = false;
806 	int irq, err, i;
807 
808 	sfp = sfp_alloc(&pdev->dev);
809 	if (IS_ERR(sfp))
810 		return PTR_ERR(sfp);
811 
812 	platform_set_drvdata(pdev, sfp);
813 
814 	err = devm_add_action(sfp->dev, sfp_cleanup, sfp);
815 	if (err < 0)
816 		return err;
817 
818 	if (pdev->dev.of_node) {
819 		struct device_node *node = pdev->dev.of_node;
820 		struct device_node *np;
821 
822 		np = of_parse_phandle(node, "i2c-bus", 0);
823 		if (np) {
824 			struct i2c_adapter *i2c;
825 
826 			i2c = of_find_i2c_adapter_by_node(np);
827 			of_node_put(np);
828 			if (!i2c)
829 				return -EPROBE_DEFER;
830 
831 			err = sfp_i2c_configure(sfp, i2c);
832 			if (err < 0) {
833 				i2c_put_adapter(i2c);
834 				return err;
835 			}
836 		}
837 
838 		for (i = 0; i < GPIO_MAX; i++) {
839 			sfp->gpio[i] = devm_gpiod_get_optional(sfp->dev,
840 					   gpio_of_names[i], gpio_flags[i]);
841 			if (IS_ERR(sfp->gpio[i]))
842 				return PTR_ERR(sfp->gpio[i]);
843 		}
844 
845 		sfp->get_state = sfp_gpio_get_state;
846 		sfp->set_state = sfp_gpio_set_state;
847 	}
848 
849 	sfp->sfp_bus = sfp_register_socket(sfp->dev, sfp, &sfp_module_ops);
850 	if (!sfp->sfp_bus)
851 		return -ENOMEM;
852 
853 	/* Get the initial state, and always signal TX disable,
854 	 * since the network interface will not be up.
855 	 */
856 	sfp->state = sfp_get_state(sfp) | SFP_F_TX_DISABLE;
857 
858 	if (sfp->gpio[GPIO_RATE_SELECT] &&
859 	    gpiod_get_value_cansleep(sfp->gpio[GPIO_RATE_SELECT]))
860 		sfp->state |= SFP_F_RATE_SELECT;
861 	sfp_set_state(sfp, sfp->state);
862 	sfp_module_tx_disable(sfp);
863 	rtnl_lock();
864 	if (sfp->state & SFP_F_PRESENT)
865 		sfp_sm_event(sfp, SFP_E_INSERT);
866 	rtnl_unlock();
867 
868 	for (i = 0; i < GPIO_MAX; i++) {
869 		if (gpio_flags[i] != GPIOD_IN || !sfp->gpio[i])
870 			continue;
871 
872 		irq = gpiod_to_irq(sfp->gpio[i]);
873 		if (!irq) {
874 			poll = true;
875 			continue;
876 		}
877 
878 		err = devm_request_threaded_irq(sfp->dev, irq, NULL, sfp_irq,
879 						IRQF_ONESHOT |
880 						IRQF_TRIGGER_RISING |
881 						IRQF_TRIGGER_FALLING,
882 						dev_name(sfp->dev), sfp);
883 		if (err)
884 			poll = true;
885 	}
886 
887 	if (poll)
888 		mod_delayed_work(system_wq, &sfp->poll, poll_jiffies);
889 
890 	return 0;
891 }
892 
893 static int sfp_remove(struct platform_device *pdev)
894 {
895 	struct sfp *sfp = platform_get_drvdata(pdev);
896 
897 	sfp_unregister_socket(sfp->sfp_bus);
898 
899 	return 0;
900 }
901 
902 static const struct of_device_id sfp_of_match[] = {
903 	{ .compatible = "sff,sfp", },
904 	{ },
905 };
906 MODULE_DEVICE_TABLE(of, sfp_of_match);
907 
908 static struct platform_driver sfp_driver = {
909 	.probe = sfp_probe,
910 	.remove = sfp_remove,
911 	.driver = {
912 		.name = "sfp",
913 		.of_match_table = sfp_of_match,
914 	},
915 };
916 
917 static int sfp_init(void)
918 {
919 	poll_jiffies = msecs_to_jiffies(100);
920 
921 	return platform_driver_register(&sfp_driver);
922 }
923 module_init(sfp_init);
924 
925 static void sfp_exit(void)
926 {
927 	platform_driver_unregister(&sfp_driver);
928 }
929 module_exit(sfp_exit);
930 
931 MODULE_ALIAS("platform:sfp");
932 MODULE_AUTHOR("Russell King");
933 MODULE_LICENSE("GPL v2");
934