xref: /openbmc/linux/drivers/net/phy/sfp.c (revision 06b72824)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/acpi.h>
3 #include <linux/ctype.h>
4 #include <linux/delay.h>
5 #include <linux/gpio/consumer.h>
6 #include <linux/hwmon.h>
7 #include <linux/i2c.h>
8 #include <linux/interrupt.h>
9 #include <linux/jiffies.h>
10 #include <linux/module.h>
11 #include <linux/mutex.h>
12 #include <linux/of.h>
13 #include <linux/phy.h>
14 #include <linux/platform_device.h>
15 #include <linux/rtnetlink.h>
16 #include <linux/slab.h>
17 #include <linux/workqueue.h>
18 
19 #include "mdio-i2c.h"
20 #include "sfp.h"
21 #include "swphy.h"
22 
23 enum {
24 	GPIO_MODDEF0,
25 	GPIO_LOS,
26 	GPIO_TX_FAULT,
27 	GPIO_TX_DISABLE,
28 	GPIO_RATE_SELECT,
29 	GPIO_MAX,
30 
31 	SFP_F_PRESENT = BIT(GPIO_MODDEF0),
32 	SFP_F_LOS = BIT(GPIO_LOS),
33 	SFP_F_TX_FAULT = BIT(GPIO_TX_FAULT),
34 	SFP_F_TX_DISABLE = BIT(GPIO_TX_DISABLE),
35 	SFP_F_RATE_SELECT = BIT(GPIO_RATE_SELECT),
36 
37 	SFP_E_INSERT = 0,
38 	SFP_E_REMOVE,
39 	SFP_E_DEV_ATTACH,
40 	SFP_E_DEV_DETACH,
41 	SFP_E_DEV_DOWN,
42 	SFP_E_DEV_UP,
43 	SFP_E_TX_FAULT,
44 	SFP_E_TX_CLEAR,
45 	SFP_E_LOS_HIGH,
46 	SFP_E_LOS_LOW,
47 	SFP_E_TIMEOUT,
48 
49 	SFP_MOD_EMPTY = 0,
50 	SFP_MOD_ERROR,
51 	SFP_MOD_PROBE,
52 	SFP_MOD_WAITDEV,
53 	SFP_MOD_HPOWER,
54 	SFP_MOD_WAITPWR,
55 	SFP_MOD_PRESENT,
56 
57 	SFP_DEV_DETACHED = 0,
58 	SFP_DEV_DOWN,
59 	SFP_DEV_UP,
60 
61 	SFP_S_DOWN = 0,
62 	SFP_S_FAIL,
63 	SFP_S_WAIT,
64 	SFP_S_INIT,
65 	SFP_S_INIT_PHY,
66 	SFP_S_INIT_TX_FAULT,
67 	SFP_S_WAIT_LOS,
68 	SFP_S_LINK_UP,
69 	SFP_S_TX_FAULT,
70 	SFP_S_REINIT,
71 	SFP_S_TX_DISABLE,
72 };
73 
74 static const char  * const mod_state_strings[] = {
75 	[SFP_MOD_EMPTY] = "empty",
76 	[SFP_MOD_ERROR] = "error",
77 	[SFP_MOD_PROBE] = "probe",
78 	[SFP_MOD_WAITDEV] = "waitdev",
79 	[SFP_MOD_HPOWER] = "hpower",
80 	[SFP_MOD_WAITPWR] = "waitpwr",
81 	[SFP_MOD_PRESENT] = "present",
82 };
83 
84 static const char *mod_state_to_str(unsigned short mod_state)
85 {
86 	if (mod_state >= ARRAY_SIZE(mod_state_strings))
87 		return "Unknown module state";
88 	return mod_state_strings[mod_state];
89 }
90 
91 static const char * const dev_state_strings[] = {
92 	[SFP_DEV_DETACHED] = "detached",
93 	[SFP_DEV_DOWN] = "down",
94 	[SFP_DEV_UP] = "up",
95 };
96 
97 static const char *dev_state_to_str(unsigned short dev_state)
98 {
99 	if (dev_state >= ARRAY_SIZE(dev_state_strings))
100 		return "Unknown device state";
101 	return dev_state_strings[dev_state];
102 }
103 
104 static const char * const event_strings[] = {
105 	[SFP_E_INSERT] = "insert",
106 	[SFP_E_REMOVE] = "remove",
107 	[SFP_E_DEV_ATTACH] = "dev_attach",
108 	[SFP_E_DEV_DETACH] = "dev_detach",
109 	[SFP_E_DEV_DOWN] = "dev_down",
110 	[SFP_E_DEV_UP] = "dev_up",
111 	[SFP_E_TX_FAULT] = "tx_fault",
112 	[SFP_E_TX_CLEAR] = "tx_clear",
113 	[SFP_E_LOS_HIGH] = "los_high",
114 	[SFP_E_LOS_LOW] = "los_low",
115 	[SFP_E_TIMEOUT] = "timeout",
116 };
117 
118 static const char *event_to_str(unsigned short event)
119 {
120 	if (event >= ARRAY_SIZE(event_strings))
121 		return "Unknown event";
122 	return event_strings[event];
123 }
124 
125 static const char * const sm_state_strings[] = {
126 	[SFP_S_DOWN] = "down",
127 	[SFP_S_FAIL] = "fail",
128 	[SFP_S_WAIT] = "wait",
129 	[SFP_S_INIT] = "init",
130 	[SFP_S_INIT_PHY] = "init_phy",
131 	[SFP_S_INIT_TX_FAULT] = "init_tx_fault",
132 	[SFP_S_WAIT_LOS] = "wait_los",
133 	[SFP_S_LINK_UP] = "link_up",
134 	[SFP_S_TX_FAULT] = "tx_fault",
135 	[SFP_S_REINIT] = "reinit",
136 	[SFP_S_TX_DISABLE] = "rx_disable",
137 };
138 
139 static const char *sm_state_to_str(unsigned short sm_state)
140 {
141 	if (sm_state >= ARRAY_SIZE(sm_state_strings))
142 		return "Unknown state";
143 	return sm_state_strings[sm_state];
144 }
145 
146 static const char *gpio_of_names[] = {
147 	"mod-def0",
148 	"los",
149 	"tx-fault",
150 	"tx-disable",
151 	"rate-select0",
152 };
153 
154 static const enum gpiod_flags gpio_flags[] = {
155 	GPIOD_IN,
156 	GPIOD_IN,
157 	GPIOD_IN,
158 	GPIOD_ASIS,
159 	GPIOD_ASIS,
160 };
161 
162 /* t_start_up (SFF-8431) or t_init (SFF-8472) is the time required for a
163  * non-cooled module to initialise its laser safety circuitry. We wait
164  * an initial T_WAIT period before we check the tx fault to give any PHY
165  * on board (for a copper SFP) time to initialise.
166  */
167 #define T_WAIT			msecs_to_jiffies(50)
168 #define T_START_UP		msecs_to_jiffies(300)
169 #define T_START_UP_BAD_GPON	msecs_to_jiffies(60000)
170 
171 /* t_reset is the time required to assert the TX_DISABLE signal to reset
172  * an indicated TX_FAULT.
173  */
174 #define T_RESET_US		10
175 #define T_FAULT_RECOVER		msecs_to_jiffies(1000)
176 
177 /* N_FAULT_INIT is the number of recovery attempts at module initialisation
178  * time. If the TX_FAULT signal is not deasserted after this number of
179  * attempts at clearing it, we decide that the module is faulty.
180  * N_FAULT is the same but after the module has initialised.
181  */
182 #define N_FAULT_INIT		5
183 #define N_FAULT			5
184 
185 /* T_PHY_RETRY is the time interval between attempts to probe the PHY.
186  * R_PHY_RETRY is the number of attempts.
187  */
188 #define T_PHY_RETRY		msecs_to_jiffies(50)
189 #define R_PHY_RETRY		12
190 
191 /* SFP module presence detection is poor: the three MOD DEF signals are
192  * the same length on the PCB, which means it's possible for MOD DEF 0 to
193  * connect before the I2C bus on MOD DEF 1/2.
194  *
195  * The SFF-8472 specifies t_serial ("Time from power on until module is
196  * ready for data transmission over the two wire serial bus.") as 300ms.
197  */
198 #define T_SERIAL		msecs_to_jiffies(300)
199 #define T_HPOWER_LEVEL		msecs_to_jiffies(300)
200 #define T_PROBE_RETRY_INIT	msecs_to_jiffies(100)
201 #define R_PROBE_RETRY_INIT	10
202 #define T_PROBE_RETRY_SLOW	msecs_to_jiffies(5000)
203 #define R_PROBE_RETRY_SLOW	12
204 
205 /* SFP modules appear to always have their PHY configured for bus address
206  * 0x56 (which with mdio-i2c, translates to a PHY address of 22).
207  */
208 #define SFP_PHY_ADDR	22
209 
210 struct sff_data {
211 	unsigned int gpios;
212 	bool (*module_supported)(const struct sfp_eeprom_id *id);
213 };
214 
215 struct sfp {
216 	struct device *dev;
217 	struct i2c_adapter *i2c;
218 	struct mii_bus *i2c_mii;
219 	struct sfp_bus *sfp_bus;
220 	struct phy_device *mod_phy;
221 	const struct sff_data *type;
222 	u32 max_power_mW;
223 
224 	unsigned int (*get_state)(struct sfp *);
225 	void (*set_state)(struct sfp *, unsigned int);
226 	int (*read)(struct sfp *, bool, u8, void *, size_t);
227 	int (*write)(struct sfp *, bool, u8, void *, size_t);
228 
229 	struct gpio_desc *gpio[GPIO_MAX];
230 	int gpio_irq[GPIO_MAX];
231 
232 	bool need_poll;
233 
234 	struct mutex st_mutex;			/* Protects state */
235 	unsigned int state_soft_mask;
236 	unsigned int state;
237 	struct delayed_work poll;
238 	struct delayed_work timeout;
239 	struct mutex sm_mutex;			/* Protects state machine */
240 	unsigned char sm_mod_state;
241 	unsigned char sm_mod_tries_init;
242 	unsigned char sm_mod_tries;
243 	unsigned char sm_dev_state;
244 	unsigned short sm_state;
245 	unsigned char sm_fault_retries;
246 	unsigned char sm_phy_retries;
247 
248 	struct sfp_eeprom_id id;
249 	unsigned int module_power_mW;
250 	unsigned int module_t_start_up;
251 
252 #if IS_ENABLED(CONFIG_HWMON)
253 	struct sfp_diag diag;
254 	struct delayed_work hwmon_probe;
255 	unsigned int hwmon_tries;
256 	struct device *hwmon_dev;
257 	char *hwmon_name;
258 #endif
259 
260 };
261 
262 static bool sff_module_supported(const struct sfp_eeprom_id *id)
263 {
264 	return id->base.phys_id == SFF8024_ID_SFF_8472 &&
265 	       id->base.phys_ext_id == SFP_PHYS_EXT_ID_SFP;
266 }
267 
268 static const struct sff_data sff_data = {
269 	.gpios = SFP_F_LOS | SFP_F_TX_FAULT | SFP_F_TX_DISABLE,
270 	.module_supported = sff_module_supported,
271 };
272 
273 static bool sfp_module_supported(const struct sfp_eeprom_id *id)
274 {
275 	return id->base.phys_id == SFF8024_ID_SFP &&
276 	       id->base.phys_ext_id == SFP_PHYS_EXT_ID_SFP;
277 }
278 
279 static const struct sff_data sfp_data = {
280 	.gpios = SFP_F_PRESENT | SFP_F_LOS | SFP_F_TX_FAULT |
281 		 SFP_F_TX_DISABLE | SFP_F_RATE_SELECT,
282 	.module_supported = sfp_module_supported,
283 };
284 
285 static const struct of_device_id sfp_of_match[] = {
286 	{ .compatible = "sff,sff", .data = &sff_data, },
287 	{ .compatible = "sff,sfp", .data = &sfp_data, },
288 	{ },
289 };
290 MODULE_DEVICE_TABLE(of, sfp_of_match);
291 
292 static unsigned long poll_jiffies;
293 
294 static unsigned int sfp_gpio_get_state(struct sfp *sfp)
295 {
296 	unsigned int i, state, v;
297 
298 	for (i = state = 0; i < GPIO_MAX; i++) {
299 		if (gpio_flags[i] != GPIOD_IN || !sfp->gpio[i])
300 			continue;
301 
302 		v = gpiod_get_value_cansleep(sfp->gpio[i]);
303 		if (v)
304 			state |= BIT(i);
305 	}
306 
307 	return state;
308 }
309 
310 static unsigned int sff_gpio_get_state(struct sfp *sfp)
311 {
312 	return sfp_gpio_get_state(sfp) | SFP_F_PRESENT;
313 }
314 
315 static void sfp_gpio_set_state(struct sfp *sfp, unsigned int state)
316 {
317 	if (state & SFP_F_PRESENT) {
318 		/* If the module is present, drive the signals */
319 		if (sfp->gpio[GPIO_TX_DISABLE])
320 			gpiod_direction_output(sfp->gpio[GPIO_TX_DISABLE],
321 					       state & SFP_F_TX_DISABLE);
322 		if (state & SFP_F_RATE_SELECT)
323 			gpiod_direction_output(sfp->gpio[GPIO_RATE_SELECT],
324 					       state & SFP_F_RATE_SELECT);
325 	} else {
326 		/* Otherwise, let them float to the pull-ups */
327 		if (sfp->gpio[GPIO_TX_DISABLE])
328 			gpiod_direction_input(sfp->gpio[GPIO_TX_DISABLE]);
329 		if (state & SFP_F_RATE_SELECT)
330 			gpiod_direction_input(sfp->gpio[GPIO_RATE_SELECT]);
331 	}
332 }
333 
334 static int sfp_i2c_read(struct sfp *sfp, bool a2, u8 dev_addr, void *buf,
335 			size_t len)
336 {
337 	struct i2c_msg msgs[2];
338 	u8 bus_addr = a2 ? 0x51 : 0x50;
339 	size_t this_len;
340 	int ret;
341 
342 	msgs[0].addr = bus_addr;
343 	msgs[0].flags = 0;
344 	msgs[0].len = 1;
345 	msgs[0].buf = &dev_addr;
346 	msgs[1].addr = bus_addr;
347 	msgs[1].flags = I2C_M_RD;
348 	msgs[1].len = len;
349 	msgs[1].buf = buf;
350 
351 	while (len) {
352 		this_len = len;
353 		if (this_len > 16)
354 			this_len = 16;
355 
356 		msgs[1].len = this_len;
357 
358 		ret = i2c_transfer(sfp->i2c, msgs, ARRAY_SIZE(msgs));
359 		if (ret < 0)
360 			return ret;
361 
362 		if (ret != ARRAY_SIZE(msgs))
363 			break;
364 
365 		msgs[1].buf += this_len;
366 		dev_addr += this_len;
367 		len -= this_len;
368 	}
369 
370 	return msgs[1].buf - (u8 *)buf;
371 }
372 
373 static int sfp_i2c_write(struct sfp *sfp, bool a2, u8 dev_addr, void *buf,
374 	size_t len)
375 {
376 	struct i2c_msg msgs[1];
377 	u8 bus_addr = a2 ? 0x51 : 0x50;
378 	int ret;
379 
380 	msgs[0].addr = bus_addr;
381 	msgs[0].flags = 0;
382 	msgs[0].len = 1 + len;
383 	msgs[0].buf = kmalloc(1 + len, GFP_KERNEL);
384 	if (!msgs[0].buf)
385 		return -ENOMEM;
386 
387 	msgs[0].buf[0] = dev_addr;
388 	memcpy(&msgs[0].buf[1], buf, len);
389 
390 	ret = i2c_transfer(sfp->i2c, msgs, ARRAY_SIZE(msgs));
391 
392 	kfree(msgs[0].buf);
393 
394 	if (ret < 0)
395 		return ret;
396 
397 	return ret == ARRAY_SIZE(msgs) ? len : 0;
398 }
399 
400 static int sfp_i2c_configure(struct sfp *sfp, struct i2c_adapter *i2c)
401 {
402 	struct mii_bus *i2c_mii;
403 	int ret;
404 
405 	if (!i2c_check_functionality(i2c, I2C_FUNC_I2C))
406 		return -EINVAL;
407 
408 	sfp->i2c = i2c;
409 	sfp->read = sfp_i2c_read;
410 	sfp->write = sfp_i2c_write;
411 
412 	i2c_mii = mdio_i2c_alloc(sfp->dev, i2c);
413 	if (IS_ERR(i2c_mii))
414 		return PTR_ERR(i2c_mii);
415 
416 	i2c_mii->name = "SFP I2C Bus";
417 	i2c_mii->phy_mask = ~0;
418 
419 	ret = mdiobus_register(i2c_mii);
420 	if (ret < 0) {
421 		mdiobus_free(i2c_mii);
422 		return ret;
423 	}
424 
425 	sfp->i2c_mii = i2c_mii;
426 
427 	return 0;
428 }
429 
430 /* Interface */
431 static int sfp_read(struct sfp *sfp, bool a2, u8 addr, void *buf, size_t len)
432 {
433 	return sfp->read(sfp, a2, addr, buf, len);
434 }
435 
436 static int sfp_write(struct sfp *sfp, bool a2, u8 addr, void *buf, size_t len)
437 {
438 	return sfp->write(sfp, a2, addr, buf, len);
439 }
440 
441 static unsigned int sfp_soft_get_state(struct sfp *sfp)
442 {
443 	unsigned int state = 0;
444 	u8 status;
445 	int ret;
446 
447 	ret = sfp_read(sfp, true, SFP_STATUS, &status, sizeof(status));
448 	if (ret == sizeof(status)) {
449 		if (status & SFP_STATUS_RX_LOS)
450 			state |= SFP_F_LOS;
451 		if (status & SFP_STATUS_TX_FAULT)
452 			state |= SFP_F_TX_FAULT;
453 	} else {
454 		dev_err_ratelimited(sfp->dev,
455 				    "failed to read SFP soft status: %d\n",
456 				    ret);
457 		/* Preserve the current state */
458 		state = sfp->state;
459 	}
460 
461 	return state & sfp->state_soft_mask;
462 }
463 
464 static void sfp_soft_set_state(struct sfp *sfp, unsigned int state)
465 {
466 	u8 status;
467 
468 	if (sfp_read(sfp, true, SFP_STATUS, &status, sizeof(status)) ==
469 		     sizeof(status)) {
470 		if (state & SFP_F_TX_DISABLE)
471 			status |= SFP_STATUS_TX_DISABLE_FORCE;
472 		else
473 			status &= ~SFP_STATUS_TX_DISABLE_FORCE;
474 
475 		sfp_write(sfp, true, SFP_STATUS, &status, sizeof(status));
476 	}
477 }
478 
479 static void sfp_soft_start_poll(struct sfp *sfp)
480 {
481 	const struct sfp_eeprom_id *id = &sfp->id;
482 
483 	sfp->state_soft_mask = 0;
484 	if (id->ext.enhopts & SFP_ENHOPTS_SOFT_TX_DISABLE &&
485 	    !sfp->gpio[GPIO_TX_DISABLE])
486 		sfp->state_soft_mask |= SFP_F_TX_DISABLE;
487 	if (id->ext.enhopts & SFP_ENHOPTS_SOFT_TX_FAULT &&
488 	    !sfp->gpio[GPIO_TX_FAULT])
489 		sfp->state_soft_mask |= SFP_F_TX_FAULT;
490 	if (id->ext.enhopts & SFP_ENHOPTS_SOFT_RX_LOS &&
491 	    !sfp->gpio[GPIO_LOS])
492 		sfp->state_soft_mask |= SFP_F_LOS;
493 
494 	if (sfp->state_soft_mask & (SFP_F_LOS | SFP_F_TX_FAULT) &&
495 	    !sfp->need_poll)
496 		mod_delayed_work(system_wq, &sfp->poll, poll_jiffies);
497 }
498 
499 static void sfp_soft_stop_poll(struct sfp *sfp)
500 {
501 	sfp->state_soft_mask = 0;
502 }
503 
504 static unsigned int sfp_get_state(struct sfp *sfp)
505 {
506 	unsigned int state = sfp->get_state(sfp);
507 
508 	if (state & SFP_F_PRESENT &&
509 	    sfp->state_soft_mask & (SFP_F_LOS | SFP_F_TX_FAULT))
510 		state |= sfp_soft_get_state(sfp);
511 
512 	return state;
513 }
514 
515 static void sfp_set_state(struct sfp *sfp, unsigned int state)
516 {
517 	sfp->set_state(sfp, state);
518 
519 	if (state & SFP_F_PRESENT &&
520 	    sfp->state_soft_mask & SFP_F_TX_DISABLE)
521 		sfp_soft_set_state(sfp, state);
522 }
523 
524 static unsigned int sfp_check(void *buf, size_t len)
525 {
526 	u8 *p, check;
527 
528 	for (p = buf, check = 0; len; p++, len--)
529 		check += *p;
530 
531 	return check;
532 }
533 
534 /* hwmon */
535 #if IS_ENABLED(CONFIG_HWMON)
536 static umode_t sfp_hwmon_is_visible(const void *data,
537 				    enum hwmon_sensor_types type,
538 				    u32 attr, int channel)
539 {
540 	const struct sfp *sfp = data;
541 
542 	switch (type) {
543 	case hwmon_temp:
544 		switch (attr) {
545 		case hwmon_temp_min_alarm:
546 		case hwmon_temp_max_alarm:
547 		case hwmon_temp_lcrit_alarm:
548 		case hwmon_temp_crit_alarm:
549 		case hwmon_temp_min:
550 		case hwmon_temp_max:
551 		case hwmon_temp_lcrit:
552 		case hwmon_temp_crit:
553 			if (!(sfp->id.ext.enhopts & SFP_ENHOPTS_ALARMWARN))
554 				return 0;
555 			/* fall through */
556 		case hwmon_temp_input:
557 		case hwmon_temp_label:
558 			return 0444;
559 		default:
560 			return 0;
561 		}
562 	case hwmon_in:
563 		switch (attr) {
564 		case hwmon_in_min_alarm:
565 		case hwmon_in_max_alarm:
566 		case hwmon_in_lcrit_alarm:
567 		case hwmon_in_crit_alarm:
568 		case hwmon_in_min:
569 		case hwmon_in_max:
570 		case hwmon_in_lcrit:
571 		case hwmon_in_crit:
572 			if (!(sfp->id.ext.enhopts & SFP_ENHOPTS_ALARMWARN))
573 				return 0;
574 			/* fall through */
575 		case hwmon_in_input:
576 		case hwmon_in_label:
577 			return 0444;
578 		default:
579 			return 0;
580 		}
581 	case hwmon_curr:
582 		switch (attr) {
583 		case hwmon_curr_min_alarm:
584 		case hwmon_curr_max_alarm:
585 		case hwmon_curr_lcrit_alarm:
586 		case hwmon_curr_crit_alarm:
587 		case hwmon_curr_min:
588 		case hwmon_curr_max:
589 		case hwmon_curr_lcrit:
590 		case hwmon_curr_crit:
591 			if (!(sfp->id.ext.enhopts & SFP_ENHOPTS_ALARMWARN))
592 				return 0;
593 			/* fall through */
594 		case hwmon_curr_input:
595 		case hwmon_curr_label:
596 			return 0444;
597 		default:
598 			return 0;
599 		}
600 	case hwmon_power:
601 		/* External calibration of receive power requires
602 		 * floating point arithmetic. Doing that in the kernel
603 		 * is not easy, so just skip it. If the module does
604 		 * not require external calibration, we can however
605 		 * show receiver power, since FP is then not needed.
606 		 */
607 		if (sfp->id.ext.diagmon & SFP_DIAGMON_EXT_CAL &&
608 		    channel == 1)
609 			return 0;
610 		switch (attr) {
611 		case hwmon_power_min_alarm:
612 		case hwmon_power_max_alarm:
613 		case hwmon_power_lcrit_alarm:
614 		case hwmon_power_crit_alarm:
615 		case hwmon_power_min:
616 		case hwmon_power_max:
617 		case hwmon_power_lcrit:
618 		case hwmon_power_crit:
619 			if (!(sfp->id.ext.enhopts & SFP_ENHOPTS_ALARMWARN))
620 				return 0;
621 			/* fall through */
622 		case hwmon_power_input:
623 		case hwmon_power_label:
624 			return 0444;
625 		default:
626 			return 0;
627 		}
628 	default:
629 		return 0;
630 	}
631 }
632 
633 static int sfp_hwmon_read_sensor(struct sfp *sfp, int reg, long *value)
634 {
635 	__be16 val;
636 	int err;
637 
638 	err = sfp_read(sfp, true, reg, &val, sizeof(val));
639 	if (err < 0)
640 		return err;
641 
642 	*value = be16_to_cpu(val);
643 
644 	return 0;
645 }
646 
647 static void sfp_hwmon_to_rx_power(long *value)
648 {
649 	*value = DIV_ROUND_CLOSEST(*value, 10);
650 }
651 
652 static void sfp_hwmon_calibrate(struct sfp *sfp, unsigned int slope, int offset,
653 				long *value)
654 {
655 	if (sfp->id.ext.diagmon & SFP_DIAGMON_EXT_CAL)
656 		*value = DIV_ROUND_CLOSEST(*value * slope, 256) + offset;
657 }
658 
659 static void sfp_hwmon_calibrate_temp(struct sfp *sfp, long *value)
660 {
661 	sfp_hwmon_calibrate(sfp, be16_to_cpu(sfp->diag.cal_t_slope),
662 			    be16_to_cpu(sfp->diag.cal_t_offset), value);
663 
664 	if (*value >= 0x8000)
665 		*value -= 0x10000;
666 
667 	*value = DIV_ROUND_CLOSEST(*value * 1000, 256);
668 }
669 
670 static void sfp_hwmon_calibrate_vcc(struct sfp *sfp, long *value)
671 {
672 	sfp_hwmon_calibrate(sfp, be16_to_cpu(sfp->diag.cal_v_slope),
673 			    be16_to_cpu(sfp->diag.cal_v_offset), value);
674 
675 	*value = DIV_ROUND_CLOSEST(*value, 10);
676 }
677 
678 static void sfp_hwmon_calibrate_bias(struct sfp *sfp, long *value)
679 {
680 	sfp_hwmon_calibrate(sfp, be16_to_cpu(sfp->diag.cal_txi_slope),
681 			    be16_to_cpu(sfp->diag.cal_txi_offset), value);
682 
683 	*value = DIV_ROUND_CLOSEST(*value, 500);
684 }
685 
686 static void sfp_hwmon_calibrate_tx_power(struct sfp *sfp, long *value)
687 {
688 	sfp_hwmon_calibrate(sfp, be16_to_cpu(sfp->diag.cal_txpwr_slope),
689 			    be16_to_cpu(sfp->diag.cal_txpwr_offset), value);
690 
691 	*value = DIV_ROUND_CLOSEST(*value, 10);
692 }
693 
694 static int sfp_hwmon_read_temp(struct sfp *sfp, int reg, long *value)
695 {
696 	int err;
697 
698 	err = sfp_hwmon_read_sensor(sfp, reg, value);
699 	if (err < 0)
700 		return err;
701 
702 	sfp_hwmon_calibrate_temp(sfp, value);
703 
704 	return 0;
705 }
706 
707 static int sfp_hwmon_read_vcc(struct sfp *sfp, int reg, long *value)
708 {
709 	int err;
710 
711 	err = sfp_hwmon_read_sensor(sfp, reg, value);
712 	if (err < 0)
713 		return err;
714 
715 	sfp_hwmon_calibrate_vcc(sfp, value);
716 
717 	return 0;
718 }
719 
720 static int sfp_hwmon_read_bias(struct sfp *sfp, int reg, long *value)
721 {
722 	int err;
723 
724 	err = sfp_hwmon_read_sensor(sfp, reg, value);
725 	if (err < 0)
726 		return err;
727 
728 	sfp_hwmon_calibrate_bias(sfp, value);
729 
730 	return 0;
731 }
732 
733 static int sfp_hwmon_read_tx_power(struct sfp *sfp, int reg, long *value)
734 {
735 	int err;
736 
737 	err = sfp_hwmon_read_sensor(sfp, reg, value);
738 	if (err < 0)
739 		return err;
740 
741 	sfp_hwmon_calibrate_tx_power(sfp, value);
742 
743 	return 0;
744 }
745 
746 static int sfp_hwmon_read_rx_power(struct sfp *sfp, int reg, long *value)
747 {
748 	int err;
749 
750 	err = sfp_hwmon_read_sensor(sfp, reg, value);
751 	if (err < 0)
752 		return err;
753 
754 	sfp_hwmon_to_rx_power(value);
755 
756 	return 0;
757 }
758 
759 static int sfp_hwmon_temp(struct sfp *sfp, u32 attr, long *value)
760 {
761 	u8 status;
762 	int err;
763 
764 	switch (attr) {
765 	case hwmon_temp_input:
766 		return sfp_hwmon_read_temp(sfp, SFP_TEMP, value);
767 
768 	case hwmon_temp_lcrit:
769 		*value = be16_to_cpu(sfp->diag.temp_low_alarm);
770 		sfp_hwmon_calibrate_temp(sfp, value);
771 		return 0;
772 
773 	case hwmon_temp_min:
774 		*value = be16_to_cpu(sfp->diag.temp_low_warn);
775 		sfp_hwmon_calibrate_temp(sfp, value);
776 		return 0;
777 	case hwmon_temp_max:
778 		*value = be16_to_cpu(sfp->diag.temp_high_warn);
779 		sfp_hwmon_calibrate_temp(sfp, value);
780 		return 0;
781 
782 	case hwmon_temp_crit:
783 		*value = be16_to_cpu(sfp->diag.temp_high_alarm);
784 		sfp_hwmon_calibrate_temp(sfp, value);
785 		return 0;
786 
787 	case hwmon_temp_lcrit_alarm:
788 		err = sfp_read(sfp, true, SFP_ALARM0, &status, sizeof(status));
789 		if (err < 0)
790 			return err;
791 
792 		*value = !!(status & SFP_ALARM0_TEMP_LOW);
793 		return 0;
794 
795 	case hwmon_temp_min_alarm:
796 		err = sfp_read(sfp, true, SFP_WARN0, &status, sizeof(status));
797 		if (err < 0)
798 			return err;
799 
800 		*value = !!(status & SFP_WARN0_TEMP_LOW);
801 		return 0;
802 
803 	case hwmon_temp_max_alarm:
804 		err = sfp_read(sfp, true, SFP_WARN0, &status, sizeof(status));
805 		if (err < 0)
806 			return err;
807 
808 		*value = !!(status & SFP_WARN0_TEMP_HIGH);
809 		return 0;
810 
811 	case hwmon_temp_crit_alarm:
812 		err = sfp_read(sfp, true, SFP_ALARM0, &status, sizeof(status));
813 		if (err < 0)
814 			return err;
815 
816 		*value = !!(status & SFP_ALARM0_TEMP_HIGH);
817 		return 0;
818 	default:
819 		return -EOPNOTSUPP;
820 	}
821 
822 	return -EOPNOTSUPP;
823 }
824 
825 static int sfp_hwmon_vcc(struct sfp *sfp, u32 attr, long *value)
826 {
827 	u8 status;
828 	int err;
829 
830 	switch (attr) {
831 	case hwmon_in_input:
832 		return sfp_hwmon_read_vcc(sfp, SFP_VCC, value);
833 
834 	case hwmon_in_lcrit:
835 		*value = be16_to_cpu(sfp->diag.volt_low_alarm);
836 		sfp_hwmon_calibrate_vcc(sfp, value);
837 		return 0;
838 
839 	case hwmon_in_min:
840 		*value = be16_to_cpu(sfp->diag.volt_low_warn);
841 		sfp_hwmon_calibrate_vcc(sfp, value);
842 		return 0;
843 
844 	case hwmon_in_max:
845 		*value = be16_to_cpu(sfp->diag.volt_high_warn);
846 		sfp_hwmon_calibrate_vcc(sfp, value);
847 		return 0;
848 
849 	case hwmon_in_crit:
850 		*value = be16_to_cpu(sfp->diag.volt_high_alarm);
851 		sfp_hwmon_calibrate_vcc(sfp, value);
852 		return 0;
853 
854 	case hwmon_in_lcrit_alarm:
855 		err = sfp_read(sfp, true, SFP_ALARM0, &status, sizeof(status));
856 		if (err < 0)
857 			return err;
858 
859 		*value = !!(status & SFP_ALARM0_VCC_LOW);
860 		return 0;
861 
862 	case hwmon_in_min_alarm:
863 		err = sfp_read(sfp, true, SFP_WARN0, &status, sizeof(status));
864 		if (err < 0)
865 			return err;
866 
867 		*value = !!(status & SFP_WARN0_VCC_LOW);
868 		return 0;
869 
870 	case hwmon_in_max_alarm:
871 		err = sfp_read(sfp, true, SFP_WARN0, &status, sizeof(status));
872 		if (err < 0)
873 			return err;
874 
875 		*value = !!(status & SFP_WARN0_VCC_HIGH);
876 		return 0;
877 
878 	case hwmon_in_crit_alarm:
879 		err = sfp_read(sfp, true, SFP_ALARM0, &status, sizeof(status));
880 		if (err < 0)
881 			return err;
882 
883 		*value = !!(status & SFP_ALARM0_VCC_HIGH);
884 		return 0;
885 	default:
886 		return -EOPNOTSUPP;
887 	}
888 
889 	return -EOPNOTSUPP;
890 }
891 
892 static int sfp_hwmon_bias(struct sfp *sfp, u32 attr, long *value)
893 {
894 	u8 status;
895 	int err;
896 
897 	switch (attr) {
898 	case hwmon_curr_input:
899 		return sfp_hwmon_read_bias(sfp, SFP_TX_BIAS, value);
900 
901 	case hwmon_curr_lcrit:
902 		*value = be16_to_cpu(sfp->diag.bias_low_alarm);
903 		sfp_hwmon_calibrate_bias(sfp, value);
904 		return 0;
905 
906 	case hwmon_curr_min:
907 		*value = be16_to_cpu(sfp->diag.bias_low_warn);
908 		sfp_hwmon_calibrate_bias(sfp, value);
909 		return 0;
910 
911 	case hwmon_curr_max:
912 		*value = be16_to_cpu(sfp->diag.bias_high_warn);
913 		sfp_hwmon_calibrate_bias(sfp, value);
914 		return 0;
915 
916 	case hwmon_curr_crit:
917 		*value = be16_to_cpu(sfp->diag.bias_high_alarm);
918 		sfp_hwmon_calibrate_bias(sfp, value);
919 		return 0;
920 
921 	case hwmon_curr_lcrit_alarm:
922 		err = sfp_read(sfp, true, SFP_ALARM0, &status, sizeof(status));
923 		if (err < 0)
924 			return err;
925 
926 		*value = !!(status & SFP_ALARM0_TX_BIAS_LOW);
927 		return 0;
928 
929 	case hwmon_curr_min_alarm:
930 		err = sfp_read(sfp, true, SFP_WARN0, &status, sizeof(status));
931 		if (err < 0)
932 			return err;
933 
934 		*value = !!(status & SFP_WARN0_TX_BIAS_LOW);
935 		return 0;
936 
937 	case hwmon_curr_max_alarm:
938 		err = sfp_read(sfp, true, SFP_WARN0, &status, sizeof(status));
939 		if (err < 0)
940 			return err;
941 
942 		*value = !!(status & SFP_WARN0_TX_BIAS_HIGH);
943 		return 0;
944 
945 	case hwmon_curr_crit_alarm:
946 		err = sfp_read(sfp, true, SFP_ALARM0, &status, sizeof(status));
947 		if (err < 0)
948 			return err;
949 
950 		*value = !!(status & SFP_ALARM0_TX_BIAS_HIGH);
951 		return 0;
952 	default:
953 		return -EOPNOTSUPP;
954 	}
955 
956 	return -EOPNOTSUPP;
957 }
958 
959 static int sfp_hwmon_tx_power(struct sfp *sfp, u32 attr, long *value)
960 {
961 	u8 status;
962 	int err;
963 
964 	switch (attr) {
965 	case hwmon_power_input:
966 		return sfp_hwmon_read_tx_power(sfp, SFP_TX_POWER, value);
967 
968 	case hwmon_power_lcrit:
969 		*value = be16_to_cpu(sfp->diag.txpwr_low_alarm);
970 		sfp_hwmon_calibrate_tx_power(sfp, value);
971 		return 0;
972 
973 	case hwmon_power_min:
974 		*value = be16_to_cpu(sfp->diag.txpwr_low_warn);
975 		sfp_hwmon_calibrate_tx_power(sfp, value);
976 		return 0;
977 
978 	case hwmon_power_max:
979 		*value = be16_to_cpu(sfp->diag.txpwr_high_warn);
980 		sfp_hwmon_calibrate_tx_power(sfp, value);
981 		return 0;
982 
983 	case hwmon_power_crit:
984 		*value = be16_to_cpu(sfp->diag.txpwr_high_alarm);
985 		sfp_hwmon_calibrate_tx_power(sfp, value);
986 		return 0;
987 
988 	case hwmon_power_lcrit_alarm:
989 		err = sfp_read(sfp, true, SFP_ALARM0, &status, sizeof(status));
990 		if (err < 0)
991 			return err;
992 
993 		*value = !!(status & SFP_ALARM0_TXPWR_LOW);
994 		return 0;
995 
996 	case hwmon_power_min_alarm:
997 		err = sfp_read(sfp, true, SFP_WARN0, &status, sizeof(status));
998 		if (err < 0)
999 			return err;
1000 
1001 		*value = !!(status & SFP_WARN0_TXPWR_LOW);
1002 		return 0;
1003 
1004 	case hwmon_power_max_alarm:
1005 		err = sfp_read(sfp, true, SFP_WARN0, &status, sizeof(status));
1006 		if (err < 0)
1007 			return err;
1008 
1009 		*value = !!(status & SFP_WARN0_TXPWR_HIGH);
1010 		return 0;
1011 
1012 	case hwmon_power_crit_alarm:
1013 		err = sfp_read(sfp, true, SFP_ALARM0, &status, sizeof(status));
1014 		if (err < 0)
1015 			return err;
1016 
1017 		*value = !!(status & SFP_ALARM0_TXPWR_HIGH);
1018 		return 0;
1019 	default:
1020 		return -EOPNOTSUPP;
1021 	}
1022 
1023 	return -EOPNOTSUPP;
1024 }
1025 
1026 static int sfp_hwmon_rx_power(struct sfp *sfp, u32 attr, long *value)
1027 {
1028 	u8 status;
1029 	int err;
1030 
1031 	switch (attr) {
1032 	case hwmon_power_input:
1033 		return sfp_hwmon_read_rx_power(sfp, SFP_RX_POWER, value);
1034 
1035 	case hwmon_power_lcrit:
1036 		*value = be16_to_cpu(sfp->diag.rxpwr_low_alarm);
1037 		sfp_hwmon_to_rx_power(value);
1038 		return 0;
1039 
1040 	case hwmon_power_min:
1041 		*value = be16_to_cpu(sfp->diag.rxpwr_low_warn);
1042 		sfp_hwmon_to_rx_power(value);
1043 		return 0;
1044 
1045 	case hwmon_power_max:
1046 		*value = be16_to_cpu(sfp->diag.rxpwr_high_warn);
1047 		sfp_hwmon_to_rx_power(value);
1048 		return 0;
1049 
1050 	case hwmon_power_crit:
1051 		*value = be16_to_cpu(sfp->diag.rxpwr_high_alarm);
1052 		sfp_hwmon_to_rx_power(value);
1053 		return 0;
1054 
1055 	case hwmon_power_lcrit_alarm:
1056 		err = sfp_read(sfp, true, SFP_ALARM1, &status, sizeof(status));
1057 		if (err < 0)
1058 			return err;
1059 
1060 		*value = !!(status & SFP_ALARM1_RXPWR_LOW);
1061 		return 0;
1062 
1063 	case hwmon_power_min_alarm:
1064 		err = sfp_read(sfp, true, SFP_WARN1, &status, sizeof(status));
1065 		if (err < 0)
1066 			return err;
1067 
1068 		*value = !!(status & SFP_WARN1_RXPWR_LOW);
1069 		return 0;
1070 
1071 	case hwmon_power_max_alarm:
1072 		err = sfp_read(sfp, true, SFP_WARN1, &status, sizeof(status));
1073 		if (err < 0)
1074 			return err;
1075 
1076 		*value = !!(status & SFP_WARN1_RXPWR_HIGH);
1077 		return 0;
1078 
1079 	case hwmon_power_crit_alarm:
1080 		err = sfp_read(sfp, true, SFP_ALARM1, &status, sizeof(status));
1081 		if (err < 0)
1082 			return err;
1083 
1084 		*value = !!(status & SFP_ALARM1_RXPWR_HIGH);
1085 		return 0;
1086 	default:
1087 		return -EOPNOTSUPP;
1088 	}
1089 
1090 	return -EOPNOTSUPP;
1091 }
1092 
1093 static int sfp_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
1094 			  u32 attr, int channel, long *value)
1095 {
1096 	struct sfp *sfp = dev_get_drvdata(dev);
1097 
1098 	switch (type) {
1099 	case hwmon_temp:
1100 		return sfp_hwmon_temp(sfp, attr, value);
1101 	case hwmon_in:
1102 		return sfp_hwmon_vcc(sfp, attr, value);
1103 	case hwmon_curr:
1104 		return sfp_hwmon_bias(sfp, attr, value);
1105 	case hwmon_power:
1106 		switch (channel) {
1107 		case 0:
1108 			return sfp_hwmon_tx_power(sfp, attr, value);
1109 		case 1:
1110 			return sfp_hwmon_rx_power(sfp, attr, value);
1111 		default:
1112 			return -EOPNOTSUPP;
1113 		}
1114 	default:
1115 		return -EOPNOTSUPP;
1116 	}
1117 }
1118 
1119 static const char *const sfp_hwmon_power_labels[] = {
1120 	"TX_power",
1121 	"RX_power",
1122 };
1123 
1124 static int sfp_hwmon_read_string(struct device *dev,
1125 				 enum hwmon_sensor_types type,
1126 				 u32 attr, int channel, const char **str)
1127 {
1128 	switch (type) {
1129 	case hwmon_curr:
1130 		switch (attr) {
1131 		case hwmon_curr_label:
1132 			*str = "bias";
1133 			return 0;
1134 		default:
1135 			return -EOPNOTSUPP;
1136 		}
1137 		break;
1138 	case hwmon_temp:
1139 		switch (attr) {
1140 		case hwmon_temp_label:
1141 			*str = "temperature";
1142 			return 0;
1143 		default:
1144 			return -EOPNOTSUPP;
1145 		}
1146 		break;
1147 	case hwmon_in:
1148 		switch (attr) {
1149 		case hwmon_in_label:
1150 			*str = "VCC";
1151 			return 0;
1152 		default:
1153 			return -EOPNOTSUPP;
1154 		}
1155 		break;
1156 	case hwmon_power:
1157 		switch (attr) {
1158 		case hwmon_power_label:
1159 			*str = sfp_hwmon_power_labels[channel];
1160 			return 0;
1161 		default:
1162 			return -EOPNOTSUPP;
1163 		}
1164 		break;
1165 	default:
1166 		return -EOPNOTSUPP;
1167 	}
1168 
1169 	return -EOPNOTSUPP;
1170 }
1171 
1172 static const struct hwmon_ops sfp_hwmon_ops = {
1173 	.is_visible = sfp_hwmon_is_visible,
1174 	.read = sfp_hwmon_read,
1175 	.read_string = sfp_hwmon_read_string,
1176 };
1177 
1178 static u32 sfp_hwmon_chip_config[] = {
1179 	HWMON_C_REGISTER_TZ,
1180 	0,
1181 };
1182 
1183 static const struct hwmon_channel_info sfp_hwmon_chip = {
1184 	.type = hwmon_chip,
1185 	.config = sfp_hwmon_chip_config,
1186 };
1187 
1188 static u32 sfp_hwmon_temp_config[] = {
1189 	HWMON_T_INPUT |
1190 	HWMON_T_MAX | HWMON_T_MIN |
1191 	HWMON_T_MAX_ALARM | HWMON_T_MIN_ALARM |
1192 	HWMON_T_CRIT | HWMON_T_LCRIT |
1193 	HWMON_T_CRIT_ALARM | HWMON_T_LCRIT_ALARM |
1194 	HWMON_T_LABEL,
1195 	0,
1196 };
1197 
1198 static const struct hwmon_channel_info sfp_hwmon_temp_channel_info = {
1199 	.type = hwmon_temp,
1200 	.config = sfp_hwmon_temp_config,
1201 };
1202 
1203 static u32 sfp_hwmon_vcc_config[] = {
1204 	HWMON_I_INPUT |
1205 	HWMON_I_MAX | HWMON_I_MIN |
1206 	HWMON_I_MAX_ALARM | HWMON_I_MIN_ALARM |
1207 	HWMON_I_CRIT | HWMON_I_LCRIT |
1208 	HWMON_I_CRIT_ALARM | HWMON_I_LCRIT_ALARM |
1209 	HWMON_I_LABEL,
1210 	0,
1211 };
1212 
1213 static const struct hwmon_channel_info sfp_hwmon_vcc_channel_info = {
1214 	.type = hwmon_in,
1215 	.config = sfp_hwmon_vcc_config,
1216 };
1217 
1218 static u32 sfp_hwmon_bias_config[] = {
1219 	HWMON_C_INPUT |
1220 	HWMON_C_MAX | HWMON_C_MIN |
1221 	HWMON_C_MAX_ALARM | HWMON_C_MIN_ALARM |
1222 	HWMON_C_CRIT | HWMON_C_LCRIT |
1223 	HWMON_C_CRIT_ALARM | HWMON_C_LCRIT_ALARM |
1224 	HWMON_C_LABEL,
1225 	0,
1226 };
1227 
1228 static const struct hwmon_channel_info sfp_hwmon_bias_channel_info = {
1229 	.type = hwmon_curr,
1230 	.config = sfp_hwmon_bias_config,
1231 };
1232 
1233 static u32 sfp_hwmon_power_config[] = {
1234 	/* Transmit power */
1235 	HWMON_P_INPUT |
1236 	HWMON_P_MAX | HWMON_P_MIN |
1237 	HWMON_P_MAX_ALARM | HWMON_P_MIN_ALARM |
1238 	HWMON_P_CRIT | HWMON_P_LCRIT |
1239 	HWMON_P_CRIT_ALARM | HWMON_P_LCRIT_ALARM |
1240 	HWMON_P_LABEL,
1241 	/* Receive power */
1242 	HWMON_P_INPUT |
1243 	HWMON_P_MAX | HWMON_P_MIN |
1244 	HWMON_P_MAX_ALARM | HWMON_P_MIN_ALARM |
1245 	HWMON_P_CRIT | HWMON_P_LCRIT |
1246 	HWMON_P_CRIT_ALARM | HWMON_P_LCRIT_ALARM |
1247 	HWMON_P_LABEL,
1248 	0,
1249 };
1250 
1251 static const struct hwmon_channel_info sfp_hwmon_power_channel_info = {
1252 	.type = hwmon_power,
1253 	.config = sfp_hwmon_power_config,
1254 };
1255 
1256 static const struct hwmon_channel_info *sfp_hwmon_info[] = {
1257 	&sfp_hwmon_chip,
1258 	&sfp_hwmon_vcc_channel_info,
1259 	&sfp_hwmon_temp_channel_info,
1260 	&sfp_hwmon_bias_channel_info,
1261 	&sfp_hwmon_power_channel_info,
1262 	NULL,
1263 };
1264 
1265 static const struct hwmon_chip_info sfp_hwmon_chip_info = {
1266 	.ops = &sfp_hwmon_ops,
1267 	.info = sfp_hwmon_info,
1268 };
1269 
1270 static void sfp_hwmon_probe(struct work_struct *work)
1271 {
1272 	struct sfp *sfp = container_of(work, struct sfp, hwmon_probe.work);
1273 	int err, i;
1274 
1275 	err = sfp_read(sfp, true, 0, &sfp->diag, sizeof(sfp->diag));
1276 	if (err < 0) {
1277 		if (sfp->hwmon_tries--) {
1278 			mod_delayed_work(system_wq, &sfp->hwmon_probe,
1279 					 T_PROBE_RETRY_SLOW);
1280 		} else {
1281 			dev_warn(sfp->dev, "hwmon probe failed: %d\n", err);
1282 		}
1283 		return;
1284 	}
1285 
1286 	sfp->hwmon_name = kstrdup(dev_name(sfp->dev), GFP_KERNEL);
1287 	if (!sfp->hwmon_name) {
1288 		dev_err(sfp->dev, "out of memory for hwmon name\n");
1289 		return;
1290 	}
1291 
1292 	for (i = 0; sfp->hwmon_name[i]; i++)
1293 		if (hwmon_is_bad_char(sfp->hwmon_name[i]))
1294 			sfp->hwmon_name[i] = '_';
1295 
1296 	sfp->hwmon_dev = hwmon_device_register_with_info(sfp->dev,
1297 							 sfp->hwmon_name, sfp,
1298 							 &sfp_hwmon_chip_info,
1299 							 NULL);
1300 	if (IS_ERR(sfp->hwmon_dev))
1301 		dev_err(sfp->dev, "failed to register hwmon device: %ld\n",
1302 			PTR_ERR(sfp->hwmon_dev));
1303 }
1304 
1305 static int sfp_hwmon_insert(struct sfp *sfp)
1306 {
1307 	if (sfp->id.ext.sff8472_compliance == SFP_SFF8472_COMPLIANCE_NONE)
1308 		return 0;
1309 
1310 	if (!(sfp->id.ext.diagmon & SFP_DIAGMON_DDM))
1311 		return 0;
1312 
1313 	if (sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE)
1314 		/* This driver in general does not support address
1315 		 * change.
1316 		 */
1317 		return 0;
1318 
1319 	mod_delayed_work(system_wq, &sfp->hwmon_probe, 1);
1320 	sfp->hwmon_tries = R_PROBE_RETRY_SLOW;
1321 
1322 	return 0;
1323 }
1324 
1325 static void sfp_hwmon_remove(struct sfp *sfp)
1326 {
1327 	cancel_delayed_work_sync(&sfp->hwmon_probe);
1328 	if (!IS_ERR_OR_NULL(sfp->hwmon_dev)) {
1329 		hwmon_device_unregister(sfp->hwmon_dev);
1330 		sfp->hwmon_dev = NULL;
1331 		kfree(sfp->hwmon_name);
1332 	}
1333 }
1334 
1335 static int sfp_hwmon_init(struct sfp *sfp)
1336 {
1337 	INIT_DELAYED_WORK(&sfp->hwmon_probe, sfp_hwmon_probe);
1338 
1339 	return 0;
1340 }
1341 
1342 static void sfp_hwmon_exit(struct sfp *sfp)
1343 {
1344 	cancel_delayed_work_sync(&sfp->hwmon_probe);
1345 }
1346 #else
1347 static int sfp_hwmon_insert(struct sfp *sfp)
1348 {
1349 	return 0;
1350 }
1351 
1352 static void sfp_hwmon_remove(struct sfp *sfp)
1353 {
1354 }
1355 
1356 static int sfp_hwmon_init(struct sfp *sfp)
1357 {
1358 	return 0;
1359 }
1360 
1361 static void sfp_hwmon_exit(struct sfp *sfp)
1362 {
1363 }
1364 #endif
1365 
1366 /* Helpers */
1367 static void sfp_module_tx_disable(struct sfp *sfp)
1368 {
1369 	dev_dbg(sfp->dev, "tx disable %u -> %u\n",
1370 		sfp->state & SFP_F_TX_DISABLE ? 1 : 0, 1);
1371 	sfp->state |= SFP_F_TX_DISABLE;
1372 	sfp_set_state(sfp, sfp->state);
1373 }
1374 
1375 static void sfp_module_tx_enable(struct sfp *sfp)
1376 {
1377 	dev_dbg(sfp->dev, "tx disable %u -> %u\n",
1378 		sfp->state & SFP_F_TX_DISABLE ? 1 : 0, 0);
1379 	sfp->state &= ~SFP_F_TX_DISABLE;
1380 	sfp_set_state(sfp, sfp->state);
1381 }
1382 
1383 static void sfp_module_tx_fault_reset(struct sfp *sfp)
1384 {
1385 	unsigned int state = sfp->state;
1386 
1387 	if (state & SFP_F_TX_DISABLE)
1388 		return;
1389 
1390 	sfp_set_state(sfp, state | SFP_F_TX_DISABLE);
1391 
1392 	udelay(T_RESET_US);
1393 
1394 	sfp_set_state(sfp, state);
1395 }
1396 
1397 /* SFP state machine */
1398 static void sfp_sm_set_timer(struct sfp *sfp, unsigned int timeout)
1399 {
1400 	if (timeout)
1401 		mod_delayed_work(system_power_efficient_wq, &sfp->timeout,
1402 				 timeout);
1403 	else
1404 		cancel_delayed_work(&sfp->timeout);
1405 }
1406 
1407 static void sfp_sm_next(struct sfp *sfp, unsigned int state,
1408 			unsigned int timeout)
1409 {
1410 	sfp->sm_state = state;
1411 	sfp_sm_set_timer(sfp, timeout);
1412 }
1413 
1414 static void sfp_sm_mod_next(struct sfp *sfp, unsigned int state,
1415 			    unsigned int timeout)
1416 {
1417 	sfp->sm_mod_state = state;
1418 	sfp_sm_set_timer(sfp, timeout);
1419 }
1420 
1421 static void sfp_sm_phy_detach(struct sfp *sfp)
1422 {
1423 	sfp_remove_phy(sfp->sfp_bus);
1424 	phy_device_remove(sfp->mod_phy);
1425 	phy_device_free(sfp->mod_phy);
1426 	sfp->mod_phy = NULL;
1427 }
1428 
1429 static int sfp_sm_probe_phy(struct sfp *sfp, bool is_c45)
1430 {
1431 	struct phy_device *phy;
1432 	int err;
1433 
1434 	phy = get_phy_device(sfp->i2c_mii, SFP_PHY_ADDR, is_c45);
1435 	if (phy == ERR_PTR(-ENODEV))
1436 		return PTR_ERR(phy);
1437 	if (IS_ERR(phy)) {
1438 		dev_err(sfp->dev, "mdiobus scan returned %ld\n", PTR_ERR(phy));
1439 		return PTR_ERR(phy);
1440 	}
1441 
1442 	err = phy_device_register(phy);
1443 	if (err) {
1444 		phy_device_free(phy);
1445 		dev_err(sfp->dev, "phy_device_register failed: %d\n", err);
1446 		return err;
1447 	}
1448 
1449 	err = sfp_add_phy(sfp->sfp_bus, phy);
1450 	if (err) {
1451 		phy_device_remove(phy);
1452 		phy_device_free(phy);
1453 		dev_err(sfp->dev, "sfp_add_phy failed: %d\n", err);
1454 		return err;
1455 	}
1456 
1457 	sfp->mod_phy = phy;
1458 
1459 	return 0;
1460 }
1461 
1462 static void sfp_sm_link_up(struct sfp *sfp)
1463 {
1464 	sfp_link_up(sfp->sfp_bus);
1465 	sfp_sm_next(sfp, SFP_S_LINK_UP, 0);
1466 }
1467 
1468 static void sfp_sm_link_down(struct sfp *sfp)
1469 {
1470 	sfp_link_down(sfp->sfp_bus);
1471 }
1472 
1473 static void sfp_sm_link_check_los(struct sfp *sfp)
1474 {
1475 	unsigned int los = sfp->state & SFP_F_LOS;
1476 
1477 	/* If neither SFP_OPTIONS_LOS_INVERTED nor SFP_OPTIONS_LOS_NORMAL
1478 	 * are set, we assume that no LOS signal is available.
1479 	 */
1480 	if (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_INVERTED))
1481 		los ^= SFP_F_LOS;
1482 	else if (!(sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_NORMAL)))
1483 		los = 0;
1484 
1485 	if (los)
1486 		sfp_sm_next(sfp, SFP_S_WAIT_LOS, 0);
1487 	else
1488 		sfp_sm_link_up(sfp);
1489 }
1490 
1491 static bool sfp_los_event_active(struct sfp *sfp, unsigned int event)
1492 {
1493 	return (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_INVERTED) &&
1494 		event == SFP_E_LOS_LOW) ||
1495 	       (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_NORMAL) &&
1496 		event == SFP_E_LOS_HIGH);
1497 }
1498 
1499 static bool sfp_los_event_inactive(struct sfp *sfp, unsigned int event)
1500 {
1501 	return (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_INVERTED) &&
1502 		event == SFP_E_LOS_HIGH) ||
1503 	       (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_LOS_NORMAL) &&
1504 		event == SFP_E_LOS_LOW);
1505 }
1506 
1507 static void sfp_sm_fault(struct sfp *sfp, unsigned int next_state, bool warn)
1508 {
1509 	if (sfp->sm_fault_retries && !--sfp->sm_fault_retries) {
1510 		dev_err(sfp->dev,
1511 			"module persistently indicates fault, disabling\n");
1512 		sfp_sm_next(sfp, SFP_S_TX_DISABLE, 0);
1513 	} else {
1514 		if (warn)
1515 			dev_err(sfp->dev, "module transmit fault indicated\n");
1516 
1517 		sfp_sm_next(sfp, next_state, T_FAULT_RECOVER);
1518 	}
1519 }
1520 
1521 /* Probe a SFP for a PHY device if the module supports copper - the PHY
1522  * normally sits at I2C bus address 0x56, and may either be a clause 22
1523  * or clause 45 PHY.
1524  *
1525  * Clause 22 copper SFP modules normally operate in Cisco SGMII mode with
1526  * negotiation enabled, but some may be in 1000base-X - which is for the
1527  * PHY driver to determine.
1528  *
1529  * Clause 45 copper SFP+ modules (10G) appear to switch their interface
1530  * mode according to the negotiated line speed.
1531  */
1532 static int sfp_sm_probe_for_phy(struct sfp *sfp)
1533 {
1534 	int err = 0;
1535 
1536 	switch (sfp->id.base.extended_cc) {
1537 	case SFF8024_ECC_10GBASE_T_SFI:
1538 	case SFF8024_ECC_10GBASE_T_SR:
1539 	case SFF8024_ECC_5GBASE_T:
1540 	case SFF8024_ECC_2_5GBASE_T:
1541 		err = sfp_sm_probe_phy(sfp, true);
1542 		break;
1543 
1544 	default:
1545 		if (sfp->id.base.e1000_base_t)
1546 			err = sfp_sm_probe_phy(sfp, false);
1547 		break;
1548 	}
1549 	return err;
1550 }
1551 
1552 static int sfp_module_parse_power(struct sfp *sfp)
1553 {
1554 	u32 power_mW = 1000;
1555 
1556 	if (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_POWER_DECL))
1557 		power_mW = 1500;
1558 	if (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_HIGH_POWER_LEVEL))
1559 		power_mW = 2000;
1560 
1561 	if (power_mW > sfp->max_power_mW) {
1562 		/* Module power specification exceeds the allowed maximum. */
1563 		if (sfp->id.ext.sff8472_compliance ==
1564 			SFP_SFF8472_COMPLIANCE_NONE &&
1565 		    !(sfp->id.ext.diagmon & SFP_DIAGMON_DDM)) {
1566 			/* The module appears not to implement bus address
1567 			 * 0xa2, so assume that the module powers up in the
1568 			 * indicated mode.
1569 			 */
1570 			dev_err(sfp->dev,
1571 				"Host does not support %u.%uW modules\n",
1572 				power_mW / 1000, (power_mW / 100) % 10);
1573 			return -EINVAL;
1574 		} else {
1575 			dev_warn(sfp->dev,
1576 				 "Host does not support %u.%uW modules, module left in power mode 1\n",
1577 				 power_mW / 1000, (power_mW / 100) % 10);
1578 			return 0;
1579 		}
1580 	}
1581 
1582 	/* If the module requires a higher power mode, but also requires
1583 	 * an address change sequence, warn the user that the module may
1584 	 * not be functional.
1585 	 */
1586 	if (sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE && power_mW > 1000) {
1587 		dev_warn(sfp->dev,
1588 			 "Address Change Sequence not supported but module requires %u.%uW, module may not be functional\n",
1589 			 power_mW / 1000, (power_mW / 100) % 10);
1590 		return 0;
1591 	}
1592 
1593 	sfp->module_power_mW = power_mW;
1594 
1595 	return 0;
1596 }
1597 
1598 static int sfp_sm_mod_hpower(struct sfp *sfp, bool enable)
1599 {
1600 	u8 val;
1601 	int err;
1602 
1603 	err = sfp_read(sfp, true, SFP_EXT_STATUS, &val, sizeof(val));
1604 	if (err != sizeof(val)) {
1605 		dev_err(sfp->dev, "Failed to read EEPROM: %d\n", err);
1606 		return -EAGAIN;
1607 	}
1608 
1609 	/* DM7052 reports as a high power module, responds to reads (with
1610 	 * all bytes 0xff) at 0x51 but does not accept writes.  In any case,
1611 	 * if the bit is already set, we're already in high power mode.
1612 	 */
1613 	if (!!(val & BIT(0)) == enable)
1614 		return 0;
1615 
1616 	if (enable)
1617 		val |= BIT(0);
1618 	else
1619 		val &= ~BIT(0);
1620 
1621 	err = sfp_write(sfp, true, SFP_EXT_STATUS, &val, sizeof(val));
1622 	if (err != sizeof(val)) {
1623 		dev_err(sfp->dev, "Failed to write EEPROM: %d\n", err);
1624 		return -EAGAIN;
1625 	}
1626 
1627 	if (enable)
1628 		dev_info(sfp->dev, "Module switched to %u.%uW power level\n",
1629 			 sfp->module_power_mW / 1000,
1630 			 (sfp->module_power_mW / 100) % 10);
1631 
1632 	return 0;
1633 }
1634 
1635 static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
1636 {
1637 	/* SFP module inserted - read I2C data */
1638 	struct sfp_eeprom_id id;
1639 	bool cotsworks;
1640 	u8 check;
1641 	int ret;
1642 
1643 	ret = sfp_read(sfp, false, 0, &id, sizeof(id));
1644 	if (ret < 0) {
1645 		if (report)
1646 			dev_err(sfp->dev, "failed to read EEPROM: %d\n", ret);
1647 		return -EAGAIN;
1648 	}
1649 
1650 	if (ret != sizeof(id)) {
1651 		dev_err(sfp->dev, "EEPROM short read: %d\n", ret);
1652 		return -EAGAIN;
1653 	}
1654 
1655 	/* Cotsworks do not seem to update the checksums when they
1656 	 * do the final programming with the final module part number,
1657 	 * serial number and date code.
1658 	 */
1659 	cotsworks = !memcmp(id.base.vendor_name, "COTSWORKS       ", 16);
1660 
1661 	/* Validate the checksum over the base structure */
1662 	check = sfp_check(&id.base, sizeof(id.base) - 1);
1663 	if (check != id.base.cc_base) {
1664 		if (cotsworks) {
1665 			dev_warn(sfp->dev,
1666 				 "EEPROM base structure checksum failure (0x%02x != 0x%02x)\n",
1667 				 check, id.base.cc_base);
1668 		} else {
1669 			dev_err(sfp->dev,
1670 				"EEPROM base structure checksum failure: 0x%02x != 0x%02x\n",
1671 				check, id.base.cc_base);
1672 			print_hex_dump(KERN_ERR, "sfp EE: ", DUMP_PREFIX_OFFSET,
1673 				       16, 1, &id, sizeof(id), true);
1674 			return -EINVAL;
1675 		}
1676 	}
1677 
1678 	check = sfp_check(&id.ext, sizeof(id.ext) - 1);
1679 	if (check != id.ext.cc_ext) {
1680 		if (cotsworks) {
1681 			dev_warn(sfp->dev,
1682 				 "EEPROM extended structure checksum failure (0x%02x != 0x%02x)\n",
1683 				 check, id.ext.cc_ext);
1684 		} else {
1685 			dev_err(sfp->dev,
1686 				"EEPROM extended structure checksum failure: 0x%02x != 0x%02x\n",
1687 				check, id.ext.cc_ext);
1688 			print_hex_dump(KERN_ERR, "sfp EE: ", DUMP_PREFIX_OFFSET,
1689 				       16, 1, &id, sizeof(id), true);
1690 			memset(&id.ext, 0, sizeof(id.ext));
1691 		}
1692 	}
1693 
1694 	sfp->id = id;
1695 
1696 	dev_info(sfp->dev, "module %.*s %.*s rev %.*s sn %.*s dc %.*s\n",
1697 		 (int)sizeof(id.base.vendor_name), id.base.vendor_name,
1698 		 (int)sizeof(id.base.vendor_pn), id.base.vendor_pn,
1699 		 (int)sizeof(id.base.vendor_rev), id.base.vendor_rev,
1700 		 (int)sizeof(id.ext.vendor_sn), id.ext.vendor_sn,
1701 		 (int)sizeof(id.ext.datecode), id.ext.datecode);
1702 
1703 	/* Check whether we support this module */
1704 	if (!sfp->type->module_supported(&id)) {
1705 		dev_err(sfp->dev,
1706 			"module is not supported - phys id 0x%02x 0x%02x\n",
1707 			sfp->id.base.phys_id, sfp->id.base.phys_ext_id);
1708 		return -EINVAL;
1709 	}
1710 
1711 	/* If the module requires address swap mode, warn about it */
1712 	if (sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE)
1713 		dev_warn(sfp->dev,
1714 			 "module address swap to access page 0xA2 is not supported.\n");
1715 
1716 	/* Parse the module power requirement */
1717 	ret = sfp_module_parse_power(sfp);
1718 	if (ret < 0)
1719 		return ret;
1720 
1721 	if (!memcmp(id.base.vendor_name, "ALCATELLUCENT   ", 16) &&
1722 	    !memcmp(id.base.vendor_pn, "3FE46541AA      ", 16))
1723 		sfp->module_t_start_up = T_START_UP_BAD_GPON;
1724 	else
1725 		sfp->module_t_start_up = T_START_UP;
1726 
1727 	return 0;
1728 }
1729 
1730 static void sfp_sm_mod_remove(struct sfp *sfp)
1731 {
1732 	if (sfp->sm_mod_state > SFP_MOD_WAITDEV)
1733 		sfp_module_remove(sfp->sfp_bus);
1734 
1735 	sfp_hwmon_remove(sfp);
1736 
1737 	memset(&sfp->id, 0, sizeof(sfp->id));
1738 	sfp->module_power_mW = 0;
1739 
1740 	dev_info(sfp->dev, "module removed\n");
1741 }
1742 
1743 /* This state machine tracks the upstream's state */
1744 static void sfp_sm_device(struct sfp *sfp, unsigned int event)
1745 {
1746 	switch (sfp->sm_dev_state) {
1747 	default:
1748 		if (event == SFP_E_DEV_ATTACH)
1749 			sfp->sm_dev_state = SFP_DEV_DOWN;
1750 		break;
1751 
1752 	case SFP_DEV_DOWN:
1753 		if (event == SFP_E_DEV_DETACH)
1754 			sfp->sm_dev_state = SFP_DEV_DETACHED;
1755 		else if (event == SFP_E_DEV_UP)
1756 			sfp->sm_dev_state = SFP_DEV_UP;
1757 		break;
1758 
1759 	case SFP_DEV_UP:
1760 		if (event == SFP_E_DEV_DETACH)
1761 			sfp->sm_dev_state = SFP_DEV_DETACHED;
1762 		else if (event == SFP_E_DEV_DOWN)
1763 			sfp->sm_dev_state = SFP_DEV_DOWN;
1764 		break;
1765 	}
1766 }
1767 
1768 /* This state machine tracks the insert/remove state of the module, probes
1769  * the on-board EEPROM, and sets up the power level.
1770  */
1771 static void sfp_sm_module(struct sfp *sfp, unsigned int event)
1772 {
1773 	int err;
1774 
1775 	/* Handle remove event globally, it resets this state machine */
1776 	if (event == SFP_E_REMOVE) {
1777 		if (sfp->sm_mod_state > SFP_MOD_PROBE)
1778 			sfp_sm_mod_remove(sfp);
1779 		sfp_sm_mod_next(sfp, SFP_MOD_EMPTY, 0);
1780 		return;
1781 	}
1782 
1783 	/* Handle device detach globally */
1784 	if (sfp->sm_dev_state < SFP_DEV_DOWN &&
1785 	    sfp->sm_mod_state > SFP_MOD_WAITDEV) {
1786 		if (sfp->module_power_mW > 1000 &&
1787 		    sfp->sm_mod_state > SFP_MOD_HPOWER)
1788 			sfp_sm_mod_hpower(sfp, false);
1789 		sfp_sm_mod_next(sfp, SFP_MOD_WAITDEV, 0);
1790 		return;
1791 	}
1792 
1793 	switch (sfp->sm_mod_state) {
1794 	default:
1795 		if (event == SFP_E_INSERT) {
1796 			sfp_sm_mod_next(sfp, SFP_MOD_PROBE, T_SERIAL);
1797 			sfp->sm_mod_tries_init = R_PROBE_RETRY_INIT;
1798 			sfp->sm_mod_tries = R_PROBE_RETRY_SLOW;
1799 		}
1800 		break;
1801 
1802 	case SFP_MOD_PROBE:
1803 		/* Wait for T_PROBE_INIT to time out */
1804 		if (event != SFP_E_TIMEOUT)
1805 			break;
1806 
1807 		err = sfp_sm_mod_probe(sfp, sfp->sm_mod_tries == 1);
1808 		if (err == -EAGAIN) {
1809 			if (sfp->sm_mod_tries_init &&
1810 			   --sfp->sm_mod_tries_init) {
1811 				sfp_sm_set_timer(sfp, T_PROBE_RETRY_INIT);
1812 				break;
1813 			} else if (sfp->sm_mod_tries && --sfp->sm_mod_tries) {
1814 				if (sfp->sm_mod_tries == R_PROBE_RETRY_SLOW - 1)
1815 					dev_warn(sfp->dev,
1816 						 "please wait, module slow to respond\n");
1817 				sfp_sm_set_timer(sfp, T_PROBE_RETRY_SLOW);
1818 				break;
1819 			}
1820 		}
1821 		if (err < 0) {
1822 			sfp_sm_mod_next(sfp, SFP_MOD_ERROR, 0);
1823 			break;
1824 		}
1825 
1826 		err = sfp_hwmon_insert(sfp);
1827 		if (err)
1828 			dev_warn(sfp->dev, "hwmon probe failed: %d\n", err);
1829 
1830 		sfp_sm_mod_next(sfp, SFP_MOD_WAITDEV, 0);
1831 		/* fall through */
1832 	case SFP_MOD_WAITDEV:
1833 		/* Ensure that the device is attached before proceeding */
1834 		if (sfp->sm_dev_state < SFP_DEV_DOWN)
1835 			break;
1836 
1837 		/* Report the module insertion to the upstream device */
1838 		err = sfp_module_insert(sfp->sfp_bus, &sfp->id);
1839 		if (err < 0) {
1840 			sfp_sm_mod_next(sfp, SFP_MOD_ERROR, 0);
1841 			break;
1842 		}
1843 
1844 		/* If this is a power level 1 module, we are done */
1845 		if (sfp->module_power_mW <= 1000)
1846 			goto insert;
1847 
1848 		sfp_sm_mod_next(sfp, SFP_MOD_HPOWER, 0);
1849 		/* fall through */
1850 	case SFP_MOD_HPOWER:
1851 		/* Enable high power mode */
1852 		err = sfp_sm_mod_hpower(sfp, true);
1853 		if (err < 0) {
1854 			if (err != -EAGAIN) {
1855 				sfp_module_remove(sfp->sfp_bus);
1856 				sfp_sm_mod_next(sfp, SFP_MOD_ERROR, 0);
1857 			} else {
1858 				sfp_sm_set_timer(sfp, T_PROBE_RETRY_INIT);
1859 			}
1860 			break;
1861 		}
1862 
1863 		sfp_sm_mod_next(sfp, SFP_MOD_WAITPWR, T_HPOWER_LEVEL);
1864 		break;
1865 
1866 	case SFP_MOD_WAITPWR:
1867 		/* Wait for T_HPOWER_LEVEL to time out */
1868 		if (event != SFP_E_TIMEOUT)
1869 			break;
1870 
1871 	insert:
1872 		sfp_sm_mod_next(sfp, SFP_MOD_PRESENT, 0);
1873 		break;
1874 
1875 	case SFP_MOD_PRESENT:
1876 	case SFP_MOD_ERROR:
1877 		break;
1878 	}
1879 }
1880 
1881 static void sfp_sm_main(struct sfp *sfp, unsigned int event)
1882 {
1883 	unsigned long timeout;
1884 	int ret;
1885 
1886 	/* Some events are global */
1887 	if (sfp->sm_state != SFP_S_DOWN &&
1888 	    (sfp->sm_mod_state != SFP_MOD_PRESENT ||
1889 	     sfp->sm_dev_state != SFP_DEV_UP)) {
1890 		if (sfp->sm_state == SFP_S_LINK_UP &&
1891 		    sfp->sm_dev_state == SFP_DEV_UP)
1892 			sfp_sm_link_down(sfp);
1893 		if (sfp->sm_state > SFP_S_INIT)
1894 			sfp_module_stop(sfp->sfp_bus);
1895 		if (sfp->mod_phy)
1896 			sfp_sm_phy_detach(sfp);
1897 		sfp_module_tx_disable(sfp);
1898 		sfp_soft_stop_poll(sfp);
1899 		sfp_sm_next(sfp, SFP_S_DOWN, 0);
1900 		return;
1901 	}
1902 
1903 	/* The main state machine */
1904 	switch (sfp->sm_state) {
1905 	case SFP_S_DOWN:
1906 		if (sfp->sm_mod_state != SFP_MOD_PRESENT ||
1907 		    sfp->sm_dev_state != SFP_DEV_UP)
1908 			break;
1909 
1910 		if (!(sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE))
1911 			sfp_soft_start_poll(sfp);
1912 
1913 		sfp_module_tx_enable(sfp);
1914 
1915 		/* Initialise the fault clearance retries */
1916 		sfp->sm_fault_retries = N_FAULT_INIT;
1917 
1918 		/* We need to check the TX_FAULT state, which is not defined
1919 		 * while TX_DISABLE is asserted. The earliest we want to do
1920 		 * anything (such as probe for a PHY) is 50ms.
1921 		 */
1922 		sfp_sm_next(sfp, SFP_S_WAIT, T_WAIT);
1923 		break;
1924 
1925 	case SFP_S_WAIT:
1926 		if (event != SFP_E_TIMEOUT)
1927 			break;
1928 
1929 		if (sfp->state & SFP_F_TX_FAULT) {
1930 			/* Wait up to t_init (SFF-8472) or t_start_up (SFF-8431)
1931 			 * from the TX_DISABLE deassertion for the module to
1932 			 * initialise, which is indicated by TX_FAULT
1933 			 * deasserting.
1934 			 */
1935 			timeout = sfp->module_t_start_up;
1936 			if (timeout > T_WAIT)
1937 				timeout -= T_WAIT;
1938 			else
1939 				timeout = 1;
1940 
1941 			sfp_sm_next(sfp, SFP_S_INIT, timeout);
1942 		} else {
1943 			/* TX_FAULT is not asserted, assume the module has
1944 			 * finished initialising.
1945 			 */
1946 			goto init_done;
1947 		}
1948 		break;
1949 
1950 	case SFP_S_INIT:
1951 		if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT) {
1952 			/* TX_FAULT is still asserted after t_init or
1953 			 * or t_start_up, so assume there is a fault.
1954 			 */
1955 			sfp_sm_fault(sfp, SFP_S_INIT_TX_FAULT,
1956 				     sfp->sm_fault_retries == N_FAULT_INIT);
1957 		} else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR) {
1958 	init_done:
1959 			sfp->sm_phy_retries = R_PHY_RETRY;
1960 			goto phy_probe;
1961 		}
1962 		break;
1963 
1964 	case SFP_S_INIT_PHY:
1965 		if (event != SFP_E_TIMEOUT)
1966 			break;
1967 	phy_probe:
1968 		/* TX_FAULT deasserted or we timed out with TX_FAULT
1969 		 * clear.  Probe for the PHY and check the LOS state.
1970 		 */
1971 		ret = sfp_sm_probe_for_phy(sfp);
1972 		if (ret == -ENODEV) {
1973 			if (--sfp->sm_phy_retries) {
1974 				sfp_sm_next(sfp, SFP_S_INIT_PHY, T_PHY_RETRY);
1975 				break;
1976 			} else {
1977 				dev_info(sfp->dev, "no PHY detected\n");
1978 			}
1979 		} else if (ret) {
1980 			sfp_sm_next(sfp, SFP_S_FAIL, 0);
1981 			break;
1982 		}
1983 		if (sfp_module_start(sfp->sfp_bus)) {
1984 			sfp_sm_next(sfp, SFP_S_FAIL, 0);
1985 			break;
1986 		}
1987 		sfp_sm_link_check_los(sfp);
1988 
1989 		/* Reset the fault retry count */
1990 		sfp->sm_fault_retries = N_FAULT;
1991 		break;
1992 
1993 	case SFP_S_INIT_TX_FAULT:
1994 		if (event == SFP_E_TIMEOUT) {
1995 			sfp_module_tx_fault_reset(sfp);
1996 			sfp_sm_next(sfp, SFP_S_INIT, sfp->module_t_start_up);
1997 		}
1998 		break;
1999 
2000 	case SFP_S_WAIT_LOS:
2001 		if (event == SFP_E_TX_FAULT)
2002 			sfp_sm_fault(sfp, SFP_S_TX_FAULT, true);
2003 		else if (sfp_los_event_inactive(sfp, event))
2004 			sfp_sm_link_up(sfp);
2005 		break;
2006 
2007 	case SFP_S_LINK_UP:
2008 		if (event == SFP_E_TX_FAULT) {
2009 			sfp_sm_link_down(sfp);
2010 			sfp_sm_fault(sfp, SFP_S_TX_FAULT, true);
2011 		} else if (sfp_los_event_active(sfp, event)) {
2012 			sfp_sm_link_down(sfp);
2013 			sfp_sm_next(sfp, SFP_S_WAIT_LOS, 0);
2014 		}
2015 		break;
2016 
2017 	case SFP_S_TX_FAULT:
2018 		if (event == SFP_E_TIMEOUT) {
2019 			sfp_module_tx_fault_reset(sfp);
2020 			sfp_sm_next(sfp, SFP_S_REINIT, sfp->module_t_start_up);
2021 		}
2022 		break;
2023 
2024 	case SFP_S_REINIT:
2025 		if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT) {
2026 			sfp_sm_fault(sfp, SFP_S_TX_FAULT, false);
2027 		} else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR) {
2028 			dev_info(sfp->dev, "module transmit fault recovered\n");
2029 			sfp_sm_link_check_los(sfp);
2030 		}
2031 		break;
2032 
2033 	case SFP_S_TX_DISABLE:
2034 		break;
2035 	}
2036 }
2037 
2038 static void sfp_sm_event(struct sfp *sfp, unsigned int event)
2039 {
2040 	mutex_lock(&sfp->sm_mutex);
2041 
2042 	dev_dbg(sfp->dev, "SM: enter %s:%s:%s event %s\n",
2043 		mod_state_to_str(sfp->sm_mod_state),
2044 		dev_state_to_str(sfp->sm_dev_state),
2045 		sm_state_to_str(sfp->sm_state),
2046 		event_to_str(event));
2047 
2048 	sfp_sm_device(sfp, event);
2049 	sfp_sm_module(sfp, event);
2050 	sfp_sm_main(sfp, event);
2051 
2052 	dev_dbg(sfp->dev, "SM: exit %s:%s:%s\n",
2053 		mod_state_to_str(sfp->sm_mod_state),
2054 		dev_state_to_str(sfp->sm_dev_state),
2055 		sm_state_to_str(sfp->sm_state));
2056 
2057 	mutex_unlock(&sfp->sm_mutex);
2058 }
2059 
2060 static void sfp_attach(struct sfp *sfp)
2061 {
2062 	sfp_sm_event(sfp, SFP_E_DEV_ATTACH);
2063 }
2064 
2065 static void sfp_detach(struct sfp *sfp)
2066 {
2067 	sfp_sm_event(sfp, SFP_E_DEV_DETACH);
2068 }
2069 
2070 static void sfp_start(struct sfp *sfp)
2071 {
2072 	sfp_sm_event(sfp, SFP_E_DEV_UP);
2073 }
2074 
2075 static void sfp_stop(struct sfp *sfp)
2076 {
2077 	sfp_sm_event(sfp, SFP_E_DEV_DOWN);
2078 }
2079 
2080 static int sfp_module_info(struct sfp *sfp, struct ethtool_modinfo *modinfo)
2081 {
2082 	/* locking... and check module is present */
2083 
2084 	if (sfp->id.ext.sff8472_compliance &&
2085 	    !(sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE)) {
2086 		modinfo->type = ETH_MODULE_SFF_8472;
2087 		modinfo->eeprom_len = ETH_MODULE_SFF_8472_LEN;
2088 	} else {
2089 		modinfo->type = ETH_MODULE_SFF_8079;
2090 		modinfo->eeprom_len = ETH_MODULE_SFF_8079_LEN;
2091 	}
2092 	return 0;
2093 }
2094 
2095 static int sfp_module_eeprom(struct sfp *sfp, struct ethtool_eeprom *ee,
2096 			     u8 *data)
2097 {
2098 	unsigned int first, last, len;
2099 	int ret;
2100 
2101 	if (ee->len == 0)
2102 		return -EINVAL;
2103 
2104 	first = ee->offset;
2105 	last = ee->offset + ee->len;
2106 	if (first < ETH_MODULE_SFF_8079_LEN) {
2107 		len = min_t(unsigned int, last, ETH_MODULE_SFF_8079_LEN);
2108 		len -= first;
2109 
2110 		ret = sfp_read(sfp, false, first, data, len);
2111 		if (ret < 0)
2112 			return ret;
2113 
2114 		first += len;
2115 		data += len;
2116 	}
2117 	if (first < ETH_MODULE_SFF_8472_LEN && last > ETH_MODULE_SFF_8079_LEN) {
2118 		len = min_t(unsigned int, last, ETH_MODULE_SFF_8472_LEN);
2119 		len -= first;
2120 		first -= ETH_MODULE_SFF_8079_LEN;
2121 
2122 		ret = sfp_read(sfp, true, first, data, len);
2123 		if (ret < 0)
2124 			return ret;
2125 	}
2126 	return 0;
2127 }
2128 
2129 static const struct sfp_socket_ops sfp_module_ops = {
2130 	.attach = sfp_attach,
2131 	.detach = sfp_detach,
2132 	.start = sfp_start,
2133 	.stop = sfp_stop,
2134 	.module_info = sfp_module_info,
2135 	.module_eeprom = sfp_module_eeprom,
2136 };
2137 
2138 static void sfp_timeout(struct work_struct *work)
2139 {
2140 	struct sfp *sfp = container_of(work, struct sfp, timeout.work);
2141 
2142 	rtnl_lock();
2143 	sfp_sm_event(sfp, SFP_E_TIMEOUT);
2144 	rtnl_unlock();
2145 }
2146 
2147 static void sfp_check_state(struct sfp *sfp)
2148 {
2149 	unsigned int state, i, changed;
2150 
2151 	mutex_lock(&sfp->st_mutex);
2152 	state = sfp_get_state(sfp);
2153 	changed = state ^ sfp->state;
2154 	changed &= SFP_F_PRESENT | SFP_F_LOS | SFP_F_TX_FAULT;
2155 
2156 	for (i = 0; i < GPIO_MAX; i++)
2157 		if (changed & BIT(i))
2158 			dev_dbg(sfp->dev, "%s %u -> %u\n", gpio_of_names[i],
2159 				!!(sfp->state & BIT(i)), !!(state & BIT(i)));
2160 
2161 	state |= sfp->state & (SFP_F_TX_DISABLE | SFP_F_RATE_SELECT);
2162 	sfp->state = state;
2163 
2164 	rtnl_lock();
2165 	if (changed & SFP_F_PRESENT)
2166 		sfp_sm_event(sfp, state & SFP_F_PRESENT ?
2167 				SFP_E_INSERT : SFP_E_REMOVE);
2168 
2169 	if (changed & SFP_F_TX_FAULT)
2170 		sfp_sm_event(sfp, state & SFP_F_TX_FAULT ?
2171 				SFP_E_TX_FAULT : SFP_E_TX_CLEAR);
2172 
2173 	if (changed & SFP_F_LOS)
2174 		sfp_sm_event(sfp, state & SFP_F_LOS ?
2175 				SFP_E_LOS_HIGH : SFP_E_LOS_LOW);
2176 	rtnl_unlock();
2177 	mutex_unlock(&sfp->st_mutex);
2178 }
2179 
2180 static irqreturn_t sfp_irq(int irq, void *data)
2181 {
2182 	struct sfp *sfp = data;
2183 
2184 	sfp_check_state(sfp);
2185 
2186 	return IRQ_HANDLED;
2187 }
2188 
2189 static void sfp_poll(struct work_struct *work)
2190 {
2191 	struct sfp *sfp = container_of(work, struct sfp, poll.work);
2192 
2193 	sfp_check_state(sfp);
2194 
2195 	if (sfp->state_soft_mask & (SFP_F_LOS | SFP_F_TX_FAULT) ||
2196 	    sfp->need_poll)
2197 		mod_delayed_work(system_wq, &sfp->poll, poll_jiffies);
2198 }
2199 
2200 static struct sfp *sfp_alloc(struct device *dev)
2201 {
2202 	struct sfp *sfp;
2203 
2204 	sfp = kzalloc(sizeof(*sfp), GFP_KERNEL);
2205 	if (!sfp)
2206 		return ERR_PTR(-ENOMEM);
2207 
2208 	sfp->dev = dev;
2209 
2210 	mutex_init(&sfp->sm_mutex);
2211 	mutex_init(&sfp->st_mutex);
2212 	INIT_DELAYED_WORK(&sfp->poll, sfp_poll);
2213 	INIT_DELAYED_WORK(&sfp->timeout, sfp_timeout);
2214 
2215 	sfp_hwmon_init(sfp);
2216 
2217 	return sfp;
2218 }
2219 
2220 static void sfp_cleanup(void *data)
2221 {
2222 	struct sfp *sfp = data;
2223 
2224 	sfp_hwmon_exit(sfp);
2225 
2226 	cancel_delayed_work_sync(&sfp->poll);
2227 	cancel_delayed_work_sync(&sfp->timeout);
2228 	if (sfp->i2c_mii) {
2229 		mdiobus_unregister(sfp->i2c_mii);
2230 		mdiobus_free(sfp->i2c_mii);
2231 	}
2232 	if (sfp->i2c)
2233 		i2c_put_adapter(sfp->i2c);
2234 	kfree(sfp);
2235 }
2236 
2237 static int sfp_probe(struct platform_device *pdev)
2238 {
2239 	const struct sff_data *sff;
2240 	struct i2c_adapter *i2c;
2241 	struct sfp *sfp;
2242 	int err, i;
2243 
2244 	sfp = sfp_alloc(&pdev->dev);
2245 	if (IS_ERR(sfp))
2246 		return PTR_ERR(sfp);
2247 
2248 	platform_set_drvdata(pdev, sfp);
2249 
2250 	err = devm_add_action(sfp->dev, sfp_cleanup, sfp);
2251 	if (err < 0)
2252 		return err;
2253 
2254 	sff = sfp->type = &sfp_data;
2255 
2256 	if (pdev->dev.of_node) {
2257 		struct device_node *node = pdev->dev.of_node;
2258 		const struct of_device_id *id;
2259 		struct device_node *np;
2260 
2261 		id = of_match_node(sfp_of_match, node);
2262 		if (WARN_ON(!id))
2263 			return -EINVAL;
2264 
2265 		sff = sfp->type = id->data;
2266 
2267 		np = of_parse_phandle(node, "i2c-bus", 0);
2268 		if (!np) {
2269 			dev_err(sfp->dev, "missing 'i2c-bus' property\n");
2270 			return -ENODEV;
2271 		}
2272 
2273 		i2c = of_find_i2c_adapter_by_node(np);
2274 		of_node_put(np);
2275 	} else if (has_acpi_companion(&pdev->dev)) {
2276 		struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
2277 		struct fwnode_handle *fw = acpi_fwnode_handle(adev);
2278 		struct fwnode_reference_args args;
2279 		struct acpi_handle *acpi_handle;
2280 		int ret;
2281 
2282 		ret = acpi_node_get_property_reference(fw, "i2c-bus", 0, &args);
2283 		if (ret || !is_acpi_device_node(args.fwnode)) {
2284 			dev_err(&pdev->dev, "missing 'i2c-bus' property\n");
2285 			return -ENODEV;
2286 		}
2287 
2288 		acpi_handle = ACPI_HANDLE_FWNODE(args.fwnode);
2289 		i2c = i2c_acpi_find_adapter_by_handle(acpi_handle);
2290 	} else {
2291 		return -EINVAL;
2292 	}
2293 
2294 	if (!i2c)
2295 		return -EPROBE_DEFER;
2296 
2297 	err = sfp_i2c_configure(sfp, i2c);
2298 	if (err < 0) {
2299 		i2c_put_adapter(i2c);
2300 		return err;
2301 	}
2302 
2303 	for (i = 0; i < GPIO_MAX; i++)
2304 		if (sff->gpios & BIT(i)) {
2305 			sfp->gpio[i] = devm_gpiod_get_optional(sfp->dev,
2306 					   gpio_of_names[i], gpio_flags[i]);
2307 			if (IS_ERR(sfp->gpio[i]))
2308 				return PTR_ERR(sfp->gpio[i]);
2309 		}
2310 
2311 	sfp->get_state = sfp_gpio_get_state;
2312 	sfp->set_state = sfp_gpio_set_state;
2313 
2314 	/* Modules that have no detect signal are always present */
2315 	if (!(sfp->gpio[GPIO_MODDEF0]))
2316 		sfp->get_state = sff_gpio_get_state;
2317 
2318 	device_property_read_u32(&pdev->dev, "maximum-power-milliwatt",
2319 				 &sfp->max_power_mW);
2320 	if (!sfp->max_power_mW)
2321 		sfp->max_power_mW = 1000;
2322 
2323 	dev_info(sfp->dev, "Host maximum power %u.%uW\n",
2324 		 sfp->max_power_mW / 1000, (sfp->max_power_mW / 100) % 10);
2325 
2326 	/* Get the initial state, and always signal TX disable,
2327 	 * since the network interface will not be up.
2328 	 */
2329 	sfp->state = sfp_get_state(sfp) | SFP_F_TX_DISABLE;
2330 
2331 	if (sfp->gpio[GPIO_RATE_SELECT] &&
2332 	    gpiod_get_value_cansleep(sfp->gpio[GPIO_RATE_SELECT]))
2333 		sfp->state |= SFP_F_RATE_SELECT;
2334 	sfp_set_state(sfp, sfp->state);
2335 	sfp_module_tx_disable(sfp);
2336 	if (sfp->state & SFP_F_PRESENT) {
2337 		rtnl_lock();
2338 		sfp_sm_event(sfp, SFP_E_INSERT);
2339 		rtnl_unlock();
2340 	}
2341 
2342 	for (i = 0; i < GPIO_MAX; i++) {
2343 		if (gpio_flags[i] != GPIOD_IN || !sfp->gpio[i])
2344 			continue;
2345 
2346 		sfp->gpio_irq[i] = gpiod_to_irq(sfp->gpio[i]);
2347 		if (!sfp->gpio_irq[i]) {
2348 			sfp->need_poll = true;
2349 			continue;
2350 		}
2351 
2352 		err = devm_request_threaded_irq(sfp->dev, sfp->gpio_irq[i],
2353 						NULL, sfp_irq,
2354 						IRQF_ONESHOT |
2355 						IRQF_TRIGGER_RISING |
2356 						IRQF_TRIGGER_FALLING,
2357 						dev_name(sfp->dev), sfp);
2358 		if (err) {
2359 			sfp->gpio_irq[i] = 0;
2360 			sfp->need_poll = true;
2361 		}
2362 	}
2363 
2364 	if (sfp->need_poll)
2365 		mod_delayed_work(system_wq, &sfp->poll, poll_jiffies);
2366 
2367 	/* We could have an issue in cases no Tx disable pin is available or
2368 	 * wired as modules using a laser as their light source will continue to
2369 	 * be active when the fiber is removed. This could be a safety issue and
2370 	 * we should at least warn the user about that.
2371 	 */
2372 	if (!sfp->gpio[GPIO_TX_DISABLE])
2373 		dev_warn(sfp->dev,
2374 			 "No tx_disable pin: SFP modules will always be emitting.\n");
2375 
2376 	sfp->sfp_bus = sfp_register_socket(sfp->dev, sfp, &sfp_module_ops);
2377 	if (!sfp->sfp_bus)
2378 		return -ENOMEM;
2379 
2380 	return 0;
2381 }
2382 
2383 static int sfp_remove(struct platform_device *pdev)
2384 {
2385 	struct sfp *sfp = platform_get_drvdata(pdev);
2386 
2387 	sfp_unregister_socket(sfp->sfp_bus);
2388 
2389 	rtnl_lock();
2390 	sfp_sm_event(sfp, SFP_E_REMOVE);
2391 	rtnl_unlock();
2392 
2393 	return 0;
2394 }
2395 
2396 static void sfp_shutdown(struct platform_device *pdev)
2397 {
2398 	struct sfp *sfp = platform_get_drvdata(pdev);
2399 	int i;
2400 
2401 	for (i = 0; i < GPIO_MAX; i++) {
2402 		if (!sfp->gpio_irq[i])
2403 			continue;
2404 
2405 		devm_free_irq(sfp->dev, sfp->gpio_irq[i], sfp);
2406 	}
2407 
2408 	cancel_delayed_work_sync(&sfp->poll);
2409 	cancel_delayed_work_sync(&sfp->timeout);
2410 }
2411 
2412 static struct platform_driver sfp_driver = {
2413 	.probe = sfp_probe,
2414 	.remove = sfp_remove,
2415 	.shutdown = sfp_shutdown,
2416 	.driver = {
2417 		.name = "sfp",
2418 		.of_match_table = sfp_of_match,
2419 	},
2420 };
2421 
2422 static int sfp_init(void)
2423 {
2424 	poll_jiffies = msecs_to_jiffies(100);
2425 
2426 	return platform_driver_register(&sfp_driver);
2427 }
2428 module_init(sfp_init);
2429 
2430 static void sfp_exit(void)
2431 {
2432 	platform_driver_unregister(&sfp_driver);
2433 }
2434 module_exit(sfp_exit);
2435 
2436 MODULE_ALIAS("platform:sfp");
2437 MODULE_AUTHOR("Russell King");
2438 MODULE_LICENSE("GPL v2");
2439