xref: /openbmc/linux/drivers/net/phy/sfp.c (revision 711aab1d)
1 #include <linux/delay.h>
2 #include <linux/gpio.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 /*
92  * SFP modules appear to always have their PHY configured for bus address
93  * 0x56 (which with mdio-i2c, translates to a PHY address of 22).
94  */
95 #define SFP_PHY_ADDR	22
96 
97 /*
98  * Give this long for the PHY to reset.
99  */
100 #define T_PHY_RESET_MS	50
101 
102 static DEFINE_MUTEX(sfp_mutex);
103 
104 struct sfp {
105 	struct device *dev;
106 	struct i2c_adapter *i2c;
107 	struct mii_bus *i2c_mii;
108 	struct sfp_bus *sfp_bus;
109 	struct phy_device *mod_phy;
110 
111 	unsigned int (*get_state)(struct sfp *);
112 	void (*set_state)(struct sfp *, unsigned int);
113 	int (*read)(struct sfp *, bool, u8, void *, size_t);
114 
115 	struct gpio_desc *gpio[GPIO_MAX];
116 
117 	unsigned int state;
118 	struct delayed_work poll;
119 	struct delayed_work timeout;
120 	struct mutex sm_mutex;
121 	unsigned char sm_mod_state;
122 	unsigned char sm_dev_state;
123 	unsigned short sm_state;
124 	unsigned int sm_retries;
125 
126 	struct sfp_eeprom_id id;
127 };
128 
129 static unsigned long poll_jiffies;
130 
131 static unsigned int sfp_gpio_get_state(struct sfp *sfp)
132 {
133 	unsigned int i, state, v;
134 
135 	for (i = state = 0; i < GPIO_MAX; i++) {
136 		if (gpio_flags[i] != GPIOD_IN || !sfp->gpio[i])
137 			continue;
138 
139 		v = gpiod_get_value_cansleep(sfp->gpio[i]);
140 		if (v)
141 			state |= BIT(i);
142 	}
143 
144 	return state;
145 }
146 
147 static void sfp_gpio_set_state(struct sfp *sfp, unsigned int state)
148 {
149 	if (state & SFP_F_PRESENT) {
150 		/* If the module is present, drive the signals */
151 		if (sfp->gpio[GPIO_TX_DISABLE])
152 			gpiod_direction_output(sfp->gpio[GPIO_TX_DISABLE],
153 						state & SFP_F_TX_DISABLE);
154 		if (state & SFP_F_RATE_SELECT)
155 			gpiod_direction_output(sfp->gpio[GPIO_RATE_SELECT],
156 						state & SFP_F_RATE_SELECT);
157 	} else {
158 		/* Otherwise, let them float to the pull-ups */
159 		if (sfp->gpio[GPIO_TX_DISABLE])
160 			gpiod_direction_input(sfp->gpio[GPIO_TX_DISABLE]);
161 		if (state & SFP_F_RATE_SELECT)
162 			gpiod_direction_input(sfp->gpio[GPIO_RATE_SELECT]);
163 	}
164 }
165 
166 static int sfp__i2c_read(struct i2c_adapter *i2c, u8 bus_addr, u8 dev_addr,
167 	void *buf, size_t len)
168 {
169 	struct i2c_msg msgs[2];
170 	int ret;
171 
172 	msgs[0].addr = bus_addr;
173 	msgs[0].flags = 0;
174 	msgs[0].len = 1;
175 	msgs[0].buf = &dev_addr;
176 	msgs[1].addr = bus_addr;
177 	msgs[1].flags = I2C_M_RD;
178 	msgs[1].len = len;
179 	msgs[1].buf = buf;
180 
181 	ret = i2c_transfer(i2c, msgs, ARRAY_SIZE(msgs));
182 	if (ret < 0)
183 		return ret;
184 
185 	return ret == ARRAY_SIZE(msgs) ? len : 0;
186 }
187 
188 static int sfp_i2c_read(struct sfp *sfp, bool a2, u8 addr, void *buf,
189 	size_t len)
190 {
191 	return sfp__i2c_read(sfp->i2c, a2 ? 0x51 : 0x50, addr, buf, len);
192 }
193 
194 static int sfp_i2c_configure(struct sfp *sfp, struct i2c_adapter *i2c)
195 {
196 	struct mii_bus *i2c_mii;
197 	int ret;
198 
199 	if (!i2c_check_functionality(i2c, I2C_FUNC_I2C))
200 		return -EINVAL;
201 
202 	sfp->i2c = i2c;
203 	sfp->read = sfp_i2c_read;
204 
205 	i2c_mii = mdio_i2c_alloc(sfp->dev, i2c);
206 	if (IS_ERR(i2c_mii))
207 		return PTR_ERR(i2c_mii);
208 
209 	i2c_mii->name = "SFP I2C Bus";
210 	i2c_mii->phy_mask = ~0;
211 
212 	ret = mdiobus_register(i2c_mii);
213 	if (ret < 0) {
214 		mdiobus_free(i2c_mii);
215 		return ret;
216 	}
217 
218 	sfp->i2c_mii = i2c_mii;
219 
220 	return 0;
221 }
222 
223 
224 /* Interface */
225 static unsigned int sfp_get_state(struct sfp *sfp)
226 {
227 	return sfp->get_state(sfp);
228 }
229 
230 static void sfp_set_state(struct sfp *sfp, unsigned int state)
231 {
232 	sfp->set_state(sfp, state);
233 }
234 
235 static int sfp_read(struct sfp *sfp, bool a2, u8 addr, void *buf, size_t len)
236 {
237 	return sfp->read(sfp, a2, addr, buf, len);
238 }
239 
240 static unsigned int sfp_check(void *buf, size_t len)
241 {
242 	u8 *p, check;
243 
244 	for (p = buf, check = 0; len; p++, len--)
245 		check += *p;
246 
247 	return check;
248 }
249 
250 /* Helpers */
251 static void sfp_module_tx_disable(struct sfp *sfp)
252 {
253 	dev_dbg(sfp->dev, "tx disable %u -> %u\n",
254 		sfp->state & SFP_F_TX_DISABLE ? 1 : 0, 1);
255 	sfp->state |= SFP_F_TX_DISABLE;
256 	sfp_set_state(sfp, sfp->state);
257 }
258 
259 static void sfp_module_tx_enable(struct sfp *sfp)
260 {
261 	dev_dbg(sfp->dev, "tx disable %u -> %u\n",
262 		sfp->state & SFP_F_TX_DISABLE ? 1 : 0, 0);
263 	sfp->state &= ~SFP_F_TX_DISABLE;
264 	sfp_set_state(sfp, sfp->state);
265 }
266 
267 static void sfp_module_tx_fault_reset(struct sfp *sfp)
268 {
269 	unsigned int state = sfp->state;
270 
271 	if (state & SFP_F_TX_DISABLE)
272 		return;
273 
274 	sfp_set_state(sfp, state | SFP_F_TX_DISABLE);
275 
276 	udelay(T_RESET_US);
277 
278 	sfp_set_state(sfp, state);
279 }
280 
281 /* SFP state machine */
282 static void sfp_sm_set_timer(struct sfp *sfp, unsigned int timeout)
283 {
284 	if (timeout)
285 		mod_delayed_work(system_power_efficient_wq, &sfp->timeout,
286 				 timeout);
287 	else
288 		cancel_delayed_work(&sfp->timeout);
289 }
290 
291 static void sfp_sm_next(struct sfp *sfp, unsigned int state,
292 			unsigned int timeout)
293 {
294 	sfp->sm_state = state;
295 	sfp_sm_set_timer(sfp, timeout);
296 }
297 
298 static void sfp_sm_ins_next(struct sfp *sfp, unsigned int state, unsigned int timeout)
299 {
300 	sfp->sm_mod_state = state;
301 	sfp_sm_set_timer(sfp, timeout);
302 }
303 
304 static void sfp_sm_phy_detach(struct sfp *sfp)
305 {
306 	phy_stop(sfp->mod_phy);
307 	sfp_remove_phy(sfp->sfp_bus);
308 	phy_device_remove(sfp->mod_phy);
309 	phy_device_free(sfp->mod_phy);
310 	sfp->mod_phy = NULL;
311 }
312 
313 static void sfp_sm_probe_phy(struct sfp *sfp)
314 {
315 	struct phy_device *phy;
316 	int err;
317 
318 	msleep(T_PHY_RESET_MS);
319 
320 	phy = mdiobus_scan(sfp->i2c_mii, SFP_PHY_ADDR);
321 	if (IS_ERR(phy)) {
322 		dev_err(sfp->dev, "mdiobus scan returned %ld\n", PTR_ERR(phy));
323 		return;
324 	}
325 	if (!phy) {
326 		dev_info(sfp->dev, "no PHY detected\n");
327 		return;
328 	}
329 
330 	err = sfp_add_phy(sfp->sfp_bus, phy);
331 	if (err) {
332 		phy_device_remove(phy);
333 		phy_device_free(phy);
334 		dev_err(sfp->dev, "sfp_add_phy failed: %d\n", err);
335 		return;
336 	}
337 
338 	sfp->mod_phy = phy;
339 	phy_start(phy);
340 }
341 
342 static void sfp_sm_link_up(struct sfp *sfp)
343 {
344 	sfp_link_up(sfp->sfp_bus);
345 	sfp_sm_next(sfp, SFP_S_LINK_UP, 0);
346 }
347 
348 static void sfp_sm_link_down(struct sfp *sfp)
349 {
350 	sfp_link_down(sfp->sfp_bus);
351 }
352 
353 static void sfp_sm_link_check_los(struct sfp *sfp)
354 {
355 	unsigned int los = sfp->state & SFP_F_LOS;
356 
357 	/* FIXME: what if neither SFP_OPTIONS_LOS_INVERTED nor
358 	 * SFP_OPTIONS_LOS_NORMAL are set?  For now, we assume
359 	 * the same as SFP_OPTIONS_LOS_NORMAL set.
360 	 */
361 	if (sfp->id.ext.options & SFP_OPTIONS_LOS_INVERTED)
362 		los ^= SFP_F_LOS;
363 
364 	if (los)
365 		sfp_sm_next(sfp, SFP_S_WAIT_LOS, 0);
366 	else
367 		sfp_sm_link_up(sfp);
368 }
369 
370 static void sfp_sm_fault(struct sfp *sfp, bool warn)
371 {
372 	if (sfp->sm_retries && !--sfp->sm_retries) {
373 		dev_err(sfp->dev, "module persistently indicates fault, disabling\n");
374 		sfp_sm_next(sfp, SFP_S_TX_DISABLE, 0);
375 	} else {
376 		if (warn)
377 			dev_err(sfp->dev, "module transmit fault indicated\n");
378 
379 		sfp_sm_next(sfp, SFP_S_TX_FAULT, T_FAULT_RECOVER);
380 	}
381 }
382 
383 static void sfp_sm_mod_init(struct sfp *sfp)
384 {
385 	sfp_module_tx_enable(sfp);
386 
387 	/* Wait t_init before indicating that the link is up, provided the
388 	 * current state indicates no TX_FAULT.  If TX_FAULT clears before
389 	 * this time, that's fine too.
390 	 */
391 	sfp_sm_next(sfp, SFP_S_INIT, T_INIT_JIFFIES);
392 	sfp->sm_retries = 5;
393 
394 	/* Setting the serdes link mode is guesswork: there's no
395 	 * field in the EEPROM which indicates what mode should
396 	 * be used.
397 	 *
398 	 * If it's a gigabit-only fiber module, it probably does
399 	 * not have a PHY, so switch to 802.3z negotiation mode.
400 	 * Otherwise, switch to SGMII mode (which is required to
401 	 * support non-gigabit speeds) and probe for a PHY.
402 	 */
403 	if (sfp->id.base.e1000_base_t ||
404 	    sfp->id.base.e100_base_lx ||
405 	    sfp->id.base.e100_base_fx)
406 		sfp_sm_probe_phy(sfp);
407 }
408 
409 static int sfp_sm_mod_probe(struct sfp *sfp)
410 {
411 	/* SFP module inserted - read I2C data */
412 	struct sfp_eeprom_id id;
413 	char vendor[17];
414 	char part[17];
415 	char sn[17];
416 	char date[9];
417 	char rev[5];
418 	u8 check;
419 	int err;
420 
421 	err = sfp_read(sfp, false, 0, &id, sizeof(id));
422 	if (err < 0) {
423 		dev_err(sfp->dev, "failed to read EEPROM: %d\n", err);
424 		return -EAGAIN;
425 	}
426 
427 	if (err != sizeof(id)) {
428 		dev_err(sfp->dev, "EEPROM short read: %d\n", err);
429 		return -EAGAIN;
430 	}
431 
432 	/* Validate the checksum over the base structure */
433 	check = sfp_check(&id.base, sizeof(id.base) - 1);
434 	if (check != id.base.cc_base) {
435 		dev_err(sfp->dev,
436 			"EEPROM base structure checksum failure: 0x%02x\n",
437 			check);
438 		print_hex_dump(KERN_ERR, "sfp EE: ", DUMP_PREFIX_OFFSET,
439 			       16, 1, &id, sizeof(id.base) - 1, true);
440 		return -EINVAL;
441 	}
442 
443 	check = sfp_check(&id.ext, sizeof(id.ext) - 1);
444 	if (check != id.ext.cc_ext) {
445 		dev_err(sfp->dev,
446 			"EEPROM extended structure checksum failure: 0x%02x\n",
447 			check);
448 		memset(&id.ext, 0, sizeof(id.ext));
449 	}
450 
451 	sfp->id = id;
452 
453 	memcpy(vendor, sfp->id.base.vendor_name, 16);
454 	vendor[16] = '\0';
455 	memcpy(part, sfp->id.base.vendor_pn, 16);
456 	part[16] = '\0';
457 	memcpy(rev, sfp->id.base.vendor_rev, 4);
458 	rev[4] = '\0';
459 	memcpy(sn, sfp->id.ext.vendor_sn, 16);
460 	sn[16] = '\0';
461 	memcpy(date, sfp->id.ext.datecode, 8);
462 	date[8] = '\0';
463 
464 	dev_info(sfp->dev, "module %s %s rev %s sn %s dc %s\n", vendor, part, rev, sn, date);
465 
466 	/* We only support SFP modules, not the legacy GBIC modules. */
467 	if (sfp->id.base.phys_id != SFP_PHYS_ID_SFP ||
468 	    sfp->id.base.phys_ext_id != SFP_PHYS_EXT_ID_SFP) {
469 		dev_err(sfp->dev, "module is not SFP - phys id 0x%02x 0x%02x\n",
470 			sfp->id.base.phys_id, sfp->id.base.phys_ext_id);
471 		return -EINVAL;
472 	}
473 
474 	return sfp_module_insert(sfp->sfp_bus, &sfp->id);
475 }
476 
477 static void sfp_sm_mod_remove(struct sfp *sfp)
478 {
479 	sfp_module_remove(sfp->sfp_bus);
480 
481 	if (sfp->mod_phy)
482 		sfp_sm_phy_detach(sfp);
483 
484 	sfp_module_tx_disable(sfp);
485 
486 	memset(&sfp->id, 0, sizeof(sfp->id));
487 
488 	dev_info(sfp->dev, "module removed\n");
489 }
490 
491 static void sfp_sm_event(struct sfp *sfp, unsigned int event)
492 {
493 	mutex_lock(&sfp->sm_mutex);
494 
495 	dev_dbg(sfp->dev, "SM: enter %u:%u:%u event %u\n",
496 		sfp->sm_mod_state, sfp->sm_dev_state, sfp->sm_state, event);
497 
498 	/* This state machine tracks the insert/remove state of
499 	 * the module, and handles probing the on-board EEPROM.
500 	 */
501 	switch (sfp->sm_mod_state) {
502 	default:
503 		if (event == SFP_E_INSERT) {
504 			sfp_module_tx_disable(sfp);
505 			sfp_sm_ins_next(sfp, SFP_MOD_PROBE, T_PROBE_INIT);
506 		}
507 		break;
508 
509 	case SFP_MOD_PROBE:
510 		if (event == SFP_E_REMOVE) {
511 			sfp_sm_ins_next(sfp, SFP_MOD_EMPTY, 0);
512 		} else if (event == SFP_E_TIMEOUT) {
513 			int err = sfp_sm_mod_probe(sfp);
514 
515 			if (err == 0)
516 				sfp_sm_ins_next(sfp, SFP_MOD_PRESENT, 0);
517 			else if (err == -EAGAIN)
518 				sfp_sm_set_timer(sfp, T_PROBE_RETRY);
519 			else
520 				sfp_sm_ins_next(sfp, SFP_MOD_ERROR, 0);
521 		}
522 		break;
523 
524 	case SFP_MOD_PRESENT:
525 	case SFP_MOD_ERROR:
526 		if (event == SFP_E_REMOVE) {
527 			sfp_sm_mod_remove(sfp);
528 			sfp_sm_ins_next(sfp, SFP_MOD_EMPTY, 0);
529 		}
530 		break;
531 	}
532 
533 	/* This state machine tracks the netdev up/down state */
534 	switch (sfp->sm_dev_state) {
535 	default:
536 		if (event == SFP_E_DEV_UP)
537 			sfp->sm_dev_state = SFP_DEV_UP;
538 		break;
539 
540 	case SFP_DEV_UP:
541 		if (event == SFP_E_DEV_DOWN) {
542 			/* If the module has a PHY, avoid raising TX disable
543 			 * as this resets the PHY. Otherwise, raise it to
544 			 * turn the laser off.
545 			 */
546 			if (!sfp->mod_phy)
547 				sfp_module_tx_disable(sfp);
548 			sfp->sm_dev_state = SFP_DEV_DOWN;
549 		}
550 		break;
551 	}
552 
553 	/* Some events are global */
554 	if (sfp->sm_state != SFP_S_DOWN &&
555 	    (sfp->sm_mod_state != SFP_MOD_PRESENT ||
556 	     sfp->sm_dev_state != SFP_DEV_UP)) {
557 		if (sfp->sm_state == SFP_S_LINK_UP &&
558 		    sfp->sm_dev_state == SFP_DEV_UP)
559 			sfp_sm_link_down(sfp);
560 		if (sfp->mod_phy)
561 			sfp_sm_phy_detach(sfp);
562 		sfp_sm_next(sfp, SFP_S_DOWN, 0);
563 		mutex_unlock(&sfp->sm_mutex);
564 		return;
565 	}
566 
567 	/* The main state machine */
568 	switch (sfp->sm_state) {
569 	case SFP_S_DOWN:
570 		if (sfp->sm_mod_state == SFP_MOD_PRESENT &&
571 		    sfp->sm_dev_state == SFP_DEV_UP)
572 			sfp_sm_mod_init(sfp);
573 		break;
574 
575 	case SFP_S_INIT:
576 		if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT)
577 			sfp_sm_fault(sfp, true);
578 		else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR)
579 			sfp_sm_link_check_los(sfp);
580 		break;
581 
582 	case SFP_S_WAIT_LOS:
583 		if (event == SFP_E_TX_FAULT)
584 			sfp_sm_fault(sfp, true);
585 		else if (event ==
586 			 (sfp->id.ext.options & SFP_OPTIONS_LOS_INVERTED ?
587 			  SFP_E_LOS_HIGH : SFP_E_LOS_LOW))
588 			sfp_sm_link_up(sfp);
589 		break;
590 
591 	case SFP_S_LINK_UP:
592 		if (event == SFP_E_TX_FAULT) {
593 			sfp_sm_link_down(sfp);
594 			sfp_sm_fault(sfp, true);
595 		} else if (event ==
596 			   (sfp->id.ext.options & SFP_OPTIONS_LOS_INVERTED ?
597 			    SFP_E_LOS_LOW : SFP_E_LOS_HIGH)) {
598 			sfp_sm_link_down(sfp);
599 			sfp_sm_next(sfp, SFP_S_WAIT_LOS, 0);
600 		}
601 		break;
602 
603 	case SFP_S_TX_FAULT:
604 		if (event == SFP_E_TIMEOUT) {
605 			sfp_module_tx_fault_reset(sfp);
606 			sfp_sm_next(sfp, SFP_S_REINIT, T_INIT_JIFFIES);
607 		}
608 		break;
609 
610 	case SFP_S_REINIT:
611 		if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT) {
612 			sfp_sm_fault(sfp, false);
613 		} else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR) {
614 			dev_info(sfp->dev, "module transmit fault recovered\n");
615 			sfp_sm_link_check_los(sfp);
616 		}
617 		break;
618 
619 	case SFP_S_TX_DISABLE:
620 		break;
621 	}
622 
623 	dev_dbg(sfp->dev, "SM: exit %u:%u:%u\n",
624 		sfp->sm_mod_state, sfp->sm_dev_state, sfp->sm_state);
625 
626 	mutex_unlock(&sfp->sm_mutex);
627 }
628 
629 static void sfp_start(struct sfp *sfp)
630 {
631 	sfp_sm_event(sfp, SFP_E_DEV_UP);
632 }
633 
634 static void sfp_stop(struct sfp *sfp)
635 {
636 	sfp_sm_event(sfp, SFP_E_DEV_DOWN);
637 }
638 
639 static int sfp_module_info(struct sfp *sfp, struct ethtool_modinfo *modinfo)
640 {
641 	/* locking... and check module is present */
642 
643 	if (sfp->id.ext.sff8472_compliance) {
644 		modinfo->type = ETH_MODULE_SFF_8472;
645 		modinfo->eeprom_len = ETH_MODULE_SFF_8472_LEN;
646 	} else {
647 		modinfo->type = ETH_MODULE_SFF_8079;
648 		modinfo->eeprom_len = ETH_MODULE_SFF_8079_LEN;
649 	}
650 	return 0;
651 }
652 
653 static int sfp_module_eeprom(struct sfp *sfp, struct ethtool_eeprom *ee,
654 	u8 *data)
655 {
656 	unsigned int first, last, len;
657 	int ret;
658 
659 	if (ee->len == 0)
660 		return -EINVAL;
661 
662 	first = ee->offset;
663 	last = ee->offset + ee->len;
664 	if (first < ETH_MODULE_SFF_8079_LEN) {
665 		len = min_t(unsigned int, last, ETH_MODULE_SFF_8079_LEN);
666 		len -= first;
667 
668 		ret = sfp->read(sfp, false, first, data, len);
669 		if (ret < 0)
670 			return ret;
671 
672 		first += len;
673 		data += len;
674 	}
675 	if (first >= ETH_MODULE_SFF_8079_LEN &&
676 	    first < ETH_MODULE_SFF_8472_LEN) {
677 		len = min_t(unsigned int, last, ETH_MODULE_SFF_8472_LEN);
678 		len -= first;
679 		first -= ETH_MODULE_SFF_8079_LEN;
680 
681 		ret = sfp->read(sfp, true, first, data, len);
682 		if (ret < 0)
683 			return ret;
684 	}
685 	return 0;
686 }
687 
688 static const struct sfp_socket_ops sfp_module_ops = {
689 	.start = sfp_start,
690 	.stop = sfp_stop,
691 	.module_info = sfp_module_info,
692 	.module_eeprom = sfp_module_eeprom,
693 };
694 
695 static void sfp_timeout(struct work_struct *work)
696 {
697 	struct sfp *sfp = container_of(work, struct sfp, timeout.work);
698 
699 	rtnl_lock();
700 	sfp_sm_event(sfp, SFP_E_TIMEOUT);
701 	rtnl_unlock();
702 }
703 
704 static void sfp_check_state(struct sfp *sfp)
705 {
706 	unsigned int state, i, changed;
707 
708 	state = sfp_get_state(sfp);
709 	changed = state ^ sfp->state;
710 	changed &= SFP_F_PRESENT | SFP_F_LOS | SFP_F_TX_FAULT;
711 
712 	for (i = 0; i < GPIO_MAX; i++)
713 		if (changed & BIT(i))
714 			dev_dbg(sfp->dev, "%s %u -> %u\n", gpio_of_names[i],
715 				!!(sfp->state & BIT(i)), !!(state & BIT(i)));
716 
717 	state |= sfp->state & (SFP_F_TX_DISABLE | SFP_F_RATE_SELECT);
718 	sfp->state = state;
719 
720 	rtnl_lock();
721 	if (changed & SFP_F_PRESENT)
722 		sfp_sm_event(sfp, state & SFP_F_PRESENT ?
723 				SFP_E_INSERT : SFP_E_REMOVE);
724 
725 	if (changed & SFP_F_TX_FAULT)
726 		sfp_sm_event(sfp, state & SFP_F_TX_FAULT ?
727 				SFP_E_TX_FAULT : SFP_E_TX_CLEAR);
728 
729 	if (changed & SFP_F_LOS)
730 		sfp_sm_event(sfp, state & SFP_F_LOS ?
731 				SFP_E_LOS_HIGH : SFP_E_LOS_LOW);
732 	rtnl_unlock();
733 }
734 
735 static irqreturn_t sfp_irq(int irq, void *data)
736 {
737 	struct sfp *sfp = data;
738 
739 	sfp_check_state(sfp);
740 
741 	return IRQ_HANDLED;
742 }
743 
744 static void sfp_poll(struct work_struct *work)
745 {
746 	struct sfp *sfp = container_of(work, struct sfp, poll.work);
747 
748 	sfp_check_state(sfp);
749 	mod_delayed_work(system_wq, &sfp->poll, poll_jiffies);
750 }
751 
752 static struct sfp *sfp_alloc(struct device *dev)
753 {
754 	struct sfp *sfp;
755 
756 	sfp = kzalloc(sizeof(*sfp), GFP_KERNEL);
757 	if (!sfp)
758 		return ERR_PTR(-ENOMEM);
759 
760 	sfp->dev = dev;
761 
762 	mutex_init(&sfp->sm_mutex);
763 	INIT_DELAYED_WORK(&sfp->poll, sfp_poll);
764 	INIT_DELAYED_WORK(&sfp->timeout, sfp_timeout);
765 
766 	return sfp;
767 }
768 
769 static void sfp_cleanup(void *data)
770 {
771 	struct sfp *sfp = data;
772 
773 	cancel_delayed_work_sync(&sfp->poll);
774 	cancel_delayed_work_sync(&sfp->timeout);
775 	if (sfp->i2c_mii) {
776 		mdiobus_unregister(sfp->i2c_mii);
777 		mdiobus_free(sfp->i2c_mii);
778 	}
779 	if (sfp->i2c)
780 		i2c_put_adapter(sfp->i2c);
781 	kfree(sfp);
782 }
783 
784 static int sfp_probe(struct platform_device *pdev)
785 {
786 	struct sfp *sfp;
787 	bool poll = false;
788 	int irq, err, i;
789 
790 	sfp = sfp_alloc(&pdev->dev);
791 	if (IS_ERR(sfp))
792 		return PTR_ERR(sfp);
793 
794 	platform_set_drvdata(pdev, sfp);
795 
796 	err = devm_add_action(sfp->dev, sfp_cleanup, sfp);
797 	if (err < 0)
798 		return err;
799 
800 	if (pdev->dev.of_node) {
801 		struct device_node *node = pdev->dev.of_node;
802 		struct device_node *np;
803 
804 		np = of_parse_phandle(node, "i2c-bus", 0);
805 		if (np) {
806 			struct i2c_adapter *i2c;
807 
808 			i2c = of_find_i2c_adapter_by_node(np);
809 			of_node_put(np);
810 			if (!i2c)
811 				return -EPROBE_DEFER;
812 
813 			err = sfp_i2c_configure(sfp, i2c);
814 			if (err < 0) {
815 				i2c_put_adapter(i2c);
816 				return err;
817 			}
818 		}
819 
820 		for (i = 0; i < GPIO_MAX; i++) {
821 			sfp->gpio[i] = devm_gpiod_get_optional(sfp->dev,
822 					   gpio_of_names[i], gpio_flags[i]);
823 			if (IS_ERR(sfp->gpio[i]))
824 				return PTR_ERR(sfp->gpio[i]);
825 		}
826 
827 		sfp->get_state = sfp_gpio_get_state;
828 		sfp->set_state = sfp_gpio_set_state;
829 	}
830 
831 	sfp->sfp_bus = sfp_register_socket(sfp->dev, sfp, &sfp_module_ops);
832 	if (!sfp->sfp_bus)
833 		return -ENOMEM;
834 
835 	/* Get the initial state, and always signal TX disable,
836 	 * since the network interface will not be up.
837 	 */
838 	sfp->state = sfp_get_state(sfp) | SFP_F_TX_DISABLE;
839 
840 	if (sfp->gpio[GPIO_RATE_SELECT] &&
841 	    gpiod_get_value_cansleep(sfp->gpio[GPIO_RATE_SELECT]))
842 		sfp->state |= SFP_F_RATE_SELECT;
843 	sfp_set_state(sfp, sfp->state);
844 	sfp_module_tx_disable(sfp);
845 	rtnl_lock();
846 	if (sfp->state & SFP_F_PRESENT)
847 		sfp_sm_event(sfp, SFP_E_INSERT);
848 	rtnl_unlock();
849 
850 	for (i = 0; i < GPIO_MAX; i++) {
851 		if (gpio_flags[i] != GPIOD_IN || !sfp->gpio[i])
852 			continue;
853 
854 		irq = gpiod_to_irq(sfp->gpio[i]);
855 		if (!irq) {
856 			poll = true;
857 			continue;
858 		}
859 
860 		err = devm_request_threaded_irq(sfp->dev, irq, NULL, sfp_irq,
861 						IRQF_ONESHOT |
862 						IRQF_TRIGGER_RISING |
863 						IRQF_TRIGGER_FALLING,
864 						dev_name(sfp->dev), sfp);
865 		if (err)
866 			poll = true;
867 	}
868 
869 	if (poll)
870 		mod_delayed_work(system_wq, &sfp->poll, poll_jiffies);
871 
872 	return 0;
873 }
874 
875 static int sfp_remove(struct platform_device *pdev)
876 {
877 	struct sfp *sfp = platform_get_drvdata(pdev);
878 
879 	sfp_unregister_socket(sfp->sfp_bus);
880 
881 	return 0;
882 }
883 
884 static const struct of_device_id sfp_of_match[] = {
885 	{ .compatible = "sff,sfp", },
886 	{ },
887 };
888 MODULE_DEVICE_TABLE(of, sfp_of_match);
889 
890 static struct platform_driver sfp_driver = {
891 	.probe = sfp_probe,
892 	.remove = sfp_remove,
893 	.driver = {
894 		.name = "sfp",
895 		.of_match_table = sfp_of_match,
896 	},
897 };
898 
899 static int sfp_init(void)
900 {
901 	poll_jiffies = msecs_to_jiffies(100);
902 
903 	return platform_driver_register(&sfp_driver);
904 }
905 module_init(sfp_init);
906 
907 static void sfp_exit(void)
908 {
909 	platform_driver_unregister(&sfp_driver);
910 }
911 module_exit(sfp_exit);
912 
913 MODULE_ALIAS("platform:sfp");
914 MODULE_AUTHOR("Russell King");
915 MODULE_LICENSE("GPL v2");
916