xref: /freebsd/sys/dev/ichiic/ig4_iic.c (revision cab6a39d7b343596a5823e65c0f7b426551ec22d)
1 /*
2  * Copyright (c) 2014 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com> and was subsequently ported
6  * to FreeBSD by Michael Gmelin <freebsd@grem.de>
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in
16  *    the documentation and/or other materials provided with the
17  *    distribution.
18  * 3. Neither the name of The DragonFly Project nor the names of its
19  *    contributors may be used to endorse or promote products derived
20  *    from this software without specific, prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 /*
40  * Intel fourth generation mobile cpus integrated I2C device.
41  *
42  * See ig4_reg.h for datasheet reference and notes.
43  * See ig4_var.h for locking semantics.
44  */
45 
46 #include "opt_acpi.h"
47 
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/kernel.h>
51 #include <sys/module.h>
52 #include <sys/errno.h>
53 #include <sys/kdb.h>
54 #include <sys/lock.h>
55 #include <sys/mutex.h>
56 #include <sys/proc.h>
57 #include <sys/sx.h>
58 #include <sys/syslog.h>
59 #include <sys/bus.h>
60 #include <sys/sysctl.h>
61 
62 #include <machine/bus.h>
63 #include <sys/rman.h>
64 
65 #ifdef DEV_ACPI
66 #include <contrib/dev/acpica/include/acpi.h>
67 #include <contrib/dev/acpica/include/accommon.h>
68 #include <dev/acpica/acpivar.h>
69 #endif
70 
71 #include <dev/iicbus/iicbus.h>
72 #include <dev/iicbus/iiconf.h>
73 
74 #include <dev/ichiic/ig4_reg.h>
75 #include <dev/ichiic/ig4_var.h>
76 
77 #define DO_POLL(sc)	(cold || kdb_active || SCHEDULER_STOPPED() || sc->poll)
78 
79 /*
80  * tLOW, tHIGH periods of the SCL clock and maximal falling time of both
81  * lines are taken from I2C specifications.
82  */
83 #define	IG4_SPEED_STD_THIGH	4000	/* nsec */
84 #define	IG4_SPEED_STD_TLOW	4700	/* nsec */
85 #define	IG4_SPEED_STD_TF_MAX	300	/* nsec */
86 #define	IG4_SPEED_FAST_THIGH	600	/* nsec */
87 #define	IG4_SPEED_FAST_TLOW	1300	/* nsec */
88 #define	IG4_SPEED_FAST_TF_MAX	300	/* nsec */
89 
90 /*
91  * Ig4 hardware parameters except Haswell are taken from intel_lpss driver
92  */
93 static const struct ig4_hw ig4iic_hw[] = {
94 	[IG4_HASWELL] = {
95 		.ic_clock_rate = 100,	/* MHz */
96 		.sda_hold_time = 90,	/* nsec */
97 		.txfifo_depth = 32,
98 		.rxfifo_depth = 32,
99 	},
100 	[IG4_ATOM] = {
101 		.ic_clock_rate = 100,
102 		.sda_fall_time = 280,
103 		.scl_fall_time = 240,
104 		.sda_hold_time = 60,
105 		.txfifo_depth = 32,
106 		.rxfifo_depth = 32,
107 	},
108 	[IG4_SKYLAKE] = {
109 		.ic_clock_rate = 120,
110 		.sda_hold_time = 230,
111 	},
112 	[IG4_APL] = {
113 		.ic_clock_rate = 133,
114 		.sda_fall_time = 171,
115 		.scl_fall_time = 208,
116 		.sda_hold_time = 207,
117 	},
118 	[IG4_CANNONLAKE] = {
119 		.ic_clock_rate = 216,
120 		.sda_hold_time = 230,
121 	},
122 	[IG4_TIGERLAKE] = {
123 		.ic_clock_rate = 133,
124 		.sda_fall_time = 171,
125 		.scl_fall_time = 208,
126 		.sda_hold_time = 42,
127 	},
128 	[IG4_GEMINILAKE] = {
129 		.ic_clock_rate = 133,
130 		.sda_fall_time = 171,
131 		.scl_fall_time = 290,
132 		.sda_hold_time = 313,
133 	},
134 };
135 
136 static int ig4iic_set_config(ig4iic_softc_t *sc, bool reset);
137 static driver_filter_t ig4iic_intr;
138 static void ig4iic_dump(ig4iic_softc_t *sc);
139 
140 static int ig4_dump;
141 SYSCTL_INT(_debug, OID_AUTO, ig4_dump, CTLFLAG_RW,
142 	   &ig4_dump, 0, "Dump controller registers");
143 
144 /*
145  * Clock registers initialization control
146  * 0 - Try read clock registers from ACPI and fallback to p.1.
147  * 1 - Calculate values based on controller type (IC clock rate).
148  * 2 - Use values inherited from DragonflyBSD driver (old behavior).
149  * 3 - Keep clock registers intact.
150  */
151 static int ig4_timings;
152 SYSCTL_INT(_debug, OID_AUTO, ig4_timings, CTLFLAG_RDTUN, &ig4_timings, 0,
153     "Controller timings 0=ACPI, 1=predefined, 2=legacy, 3=do not change");
154 
155 /*
156  * Low-level inline support functions
157  */
158 static __inline void
159 reg_write(ig4iic_softc_t *sc, uint32_t reg, uint32_t value)
160 {
161 	bus_write_4(sc->regs_res, reg, value);
162 	bus_barrier(sc->regs_res, reg, 4, BUS_SPACE_BARRIER_WRITE);
163 }
164 
165 static __inline uint32_t
166 reg_read(ig4iic_softc_t *sc, uint32_t reg)
167 {
168 	uint32_t value;
169 
170 	bus_barrier(sc->regs_res, reg, 4, BUS_SPACE_BARRIER_READ);
171 	value = bus_read_4(sc->regs_res, reg);
172 	return (value);
173 }
174 
175 static void
176 ig4iic_set_intr_mask(ig4iic_softc_t *sc, uint32_t val)
177 {
178 	if (sc->intr_mask != val) {
179 		reg_write(sc, IG4_REG_INTR_MASK, val);
180 		sc->intr_mask = val;
181 	}
182 }
183 
184 static int
185 intrstat2iic(ig4iic_softc_t *sc, uint32_t val)
186 {
187 	uint32_t src;
188 
189 	if (val & IG4_INTR_RX_UNDER)
190 		reg_read(sc, IG4_REG_CLR_RX_UNDER);
191 	if (val & IG4_INTR_RX_OVER)
192 		reg_read(sc, IG4_REG_CLR_RX_OVER);
193 	if (val & IG4_INTR_TX_OVER)
194 		reg_read(sc, IG4_REG_CLR_TX_OVER);
195 
196 	if (val & IG4_INTR_TX_ABRT) {
197 		src = reg_read(sc, IG4_REG_TX_ABRT_SOURCE);
198 		reg_read(sc, IG4_REG_CLR_TX_ABORT);
199 		/* User-requested abort. Not really a error */
200 		if (src & IG4_ABRTSRC_TRANSFER)
201 			return (IIC_ESTATUS);
202 		/* Master has lost arbitration */
203 		if (src & IG4_ABRTSRC_ARBLOST)
204 			return (IIC_EBUSBSY);
205 		/* Did not receive an acknowledge from the remote slave */
206 		if (src & (IG4_ABRTSRC_TXNOACK_ADDR7 |
207 			   IG4_ABRTSRC_TXNOACK_ADDR10_1 |
208 			   IG4_ABRTSRC_TXNOACK_ADDR10_2 |
209 			   IG4_ABRTSRC_TXNOACK_DATA |
210 			   IG4_ABRTSRC_GENCALL_NOACK))
211 			return (IIC_ENOACK);
212 		/* Programming errors */
213 		if (src & (IG4_ABRTSRC_GENCALL_READ |
214 			   IG4_ABRTSRC_NORESTART_START |
215 			   IG4_ABRTSRC_NORESTART_10))
216 			return (IIC_ENOTSUPP);
217 		/* Other errors */
218 		if (src & IG4_ABRTSRC_ACKED_START)
219 			return (IIC_EBUSERR);
220 	}
221 	/*
222 	 * TX_OVER, RX_OVER and RX_UNDER are caused by wrong RX/TX FIFO depth
223 	 * detection or driver's read/write pipelining errors.
224 	 */
225 	if (val & (IG4_INTR_TX_OVER | IG4_INTR_RX_OVER))
226 		return (IIC_EOVERFLOW);
227 	if (val & IG4_INTR_RX_UNDER)
228 		return (IIC_EUNDERFLOW);
229 
230 	return (IIC_NOERR);
231 }
232 
233 /*
234  * Enable or disable the controller and wait for the controller to acknowledge
235  * the state change.
236  */
237 static int
238 set_controller(ig4iic_softc_t *sc, uint32_t ctl)
239 {
240 	int retry;
241 	int error;
242 	uint32_t v;
243 
244 	/*
245 	 * When the controller is enabled, interrupt on STOP detect
246 	 * or receive character ready and clear pending interrupts.
247 	 */
248 	ig4iic_set_intr_mask(sc, 0);
249 	if (ctl & IG4_I2C_ENABLE)
250 		reg_read(sc, IG4_REG_CLR_INTR);
251 
252 	reg_write(sc, IG4_REG_I2C_EN, ctl);
253 	error = IIC_ETIMEOUT;
254 
255 	for (retry = 100; retry > 0; --retry) {
256 		v = reg_read(sc, IG4_REG_ENABLE_STATUS);
257 		if (((v ^ ctl) & IG4_I2C_ENABLE) == 0) {
258 			error = 0;
259 			break;
260 		}
261 		pause("i2cslv", 1);
262 	}
263 	return (error);
264 }
265 
266 /*
267  * Wait up to 25ms for the requested interrupt using a 25uS polling loop.
268  */
269 static int
270 wait_intr(ig4iic_softc_t *sc, uint32_t intr)
271 {
272 	uint32_t v;
273 	int error;
274 	int txlvl = -1;
275 	u_int count_us = 0;
276 	u_int limit_us = 1000000; /* 1sec */
277 
278 	for (;;) {
279 		/*
280 		 * Check requested status
281 		 */
282 		v = reg_read(sc, IG4_REG_RAW_INTR_STAT);
283 		error = intrstat2iic(sc, v & IG4_INTR_ERR_MASK);
284 		if (error || (v & intr))
285 			break;
286 
287 		/*
288 		 * When waiting for the transmit FIFO to become empty,
289 		 * reset the timeout if we see a change in the transmit
290 		 * FIFO level as progress is being made.
291 		 */
292 		if (intr & (IG4_INTR_TX_EMPTY | IG4_INTR_STOP_DET)) {
293 			v = reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK;
294 			if (txlvl != v) {
295 				txlvl = v;
296 				count_us = 0;
297 			}
298 		}
299 
300 		/*
301 		 * Stop if we've run out of time.
302 		 */
303 		if (count_us >= limit_us) {
304 			error = IIC_ETIMEOUT;
305 			break;
306 		}
307 
308 		/*
309 		 * When polling is not requested let the interrupt do its work.
310 		 */
311 		if (!DO_POLL(sc)) {
312 			mtx_lock_spin(&sc->io_lock);
313 			ig4iic_set_intr_mask(sc, intr | IG4_INTR_ERR_MASK);
314 			msleep_spin(sc, &sc->io_lock, "i2cwait",
315 				  (hz + 99) / 100); /* sleep up to 10ms */
316 			ig4iic_set_intr_mask(sc, 0);
317 			mtx_unlock_spin(&sc->io_lock);
318 			count_us += 10000;
319 		} else {
320 			DELAY(25);
321 			count_us += 25;
322 		}
323 	}
324 
325 	return (error);
326 }
327 
328 /*
329  * Set the slave address.  The controller must be disabled when
330  * changing the address.
331  *
332  * This operation does not issue anything to the I2C bus but sets
333  * the target address for when the controller later issues a START.
334  */
335 static void
336 set_slave_addr(ig4iic_softc_t *sc, uint8_t slave)
337 {
338 	uint32_t tar;
339 	uint32_t ctl;
340 	int use_10bit;
341 
342 	use_10bit = 0;
343 	if (sc->slave_valid && sc->last_slave == slave &&
344 	    sc->use_10bit == use_10bit) {
345 		return;
346 	}
347 	sc->use_10bit = use_10bit;
348 
349 	/*
350 	 * Wait for TXFIFO to drain before disabling the controller.
351 	 */
352 	wait_intr(sc, IG4_INTR_TX_EMPTY);
353 
354 	set_controller(sc, 0);
355 	ctl = reg_read(sc, IG4_REG_CTL);
356 	ctl &= ~IG4_CTL_10BIT;
357 	ctl |= IG4_CTL_RESTARTEN;
358 
359 	tar = slave;
360 	if (sc->use_10bit) {
361 		tar |= IG4_TAR_10BIT;
362 		ctl |= IG4_CTL_10BIT;
363 	}
364 	reg_write(sc, IG4_REG_CTL, ctl);
365 	reg_write(sc, IG4_REG_TAR_ADD, tar);
366 	set_controller(sc, IG4_I2C_ENABLE);
367 	sc->slave_valid = 1;
368 	sc->last_slave = slave;
369 }
370 
371 /*
372  *				IICBUS API FUNCTIONS
373  */
374 static int
375 ig4iic_xfer_start(ig4iic_softc_t *sc, uint16_t slave, bool repeated_start)
376 {
377 	set_slave_addr(sc, slave >> 1);
378 
379 	if (!repeated_start) {
380 		/*
381 		 * Clear any previous TX/RX FIFOs overflow/underflow bits
382 		 * and I2C bus STOP condition.
383 		 */
384 		reg_read(sc, IG4_REG_CLR_INTR);
385 	}
386 
387 	return (0);
388 }
389 
390 static bool
391 ig4iic_xfer_is_started(ig4iic_softc_t *sc)
392 {
393 	/*
394 	 * It requires that no IG4_REG_CLR_INTR or IG4_REG_CLR_START/STOP_DET
395 	 * register reads is issued after START condition.
396 	 */
397 	return ((reg_read(sc, IG4_REG_RAW_INTR_STAT) &
398 	    (IG4_INTR_START_DET | IG4_INTR_STOP_DET)) == IG4_INTR_START_DET);
399 }
400 
401 static int
402 ig4iic_xfer_abort(ig4iic_softc_t *sc)
403 {
404 	int error;
405 
406 	/* Request send of STOP condition and flush of TX FIFO */
407 	set_controller(sc, IG4_I2C_ABORT | IG4_I2C_ENABLE);
408 	/*
409 	 * Wait for the TX_ABRT interrupt with ABRTSRC_TRANSFER
410 	 * bit set in TX_ABRT_SOURCE register.
411 	 */
412 	error = wait_intr(sc, IG4_INTR_STOP_DET);
413 	set_controller(sc, IG4_I2C_ENABLE);
414 
415 	return (error == IIC_ESTATUS ? 0 : error);
416 }
417 
418 /*
419  * Amount of unread data before next burst to get better I2C bus utilization.
420  * 2 bytes is enough in FAST mode. 8 bytes is better in FAST+ and HIGH modes.
421  * Intel-recommended value is 16 for DMA transfers with 64-byte depth FIFOs.
422  */
423 #define	IG4_FIFO_LOWAT	2
424 
425 static int
426 ig4iic_read(ig4iic_softc_t *sc, uint8_t *buf, uint16_t len,
427     bool repeated_start, bool stop)
428 {
429 	uint32_t cmd;
430 	int requested = 0;
431 	int received = 0;
432 	int burst, target, lowat = 0;
433 	int error;
434 
435 	if (len == 0)
436 		return (0);
437 
438 	while (received < len) {
439 		burst = sc->cfg.txfifo_depth -
440 		    (reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
441 		if (burst <= 0) {
442 			error = wait_intr(sc, IG4_INTR_TX_EMPTY);
443 			if (error)
444 				break;
445 			burst = sc->cfg.txfifo_depth;
446 		}
447 		/* Ensure we have enough free space in RXFIFO */
448 		burst = MIN(burst, sc->cfg.rxfifo_depth - lowat);
449 		target = MIN(requested + burst, (int)len);
450 		while (requested < target) {
451 			cmd = IG4_DATA_COMMAND_RD;
452 			if (repeated_start && requested == 0)
453 				cmd |= IG4_DATA_RESTART;
454 			if (stop && requested == len - 1)
455 				cmd |= IG4_DATA_STOP;
456 			reg_write(sc, IG4_REG_DATA_CMD, cmd);
457 			requested++;
458 		}
459 		/* Leave some data queued to maintain the hardware pipeline */
460 		lowat = 0;
461 		if (requested != len && requested - received > IG4_FIFO_LOWAT)
462 			lowat = IG4_FIFO_LOWAT;
463 		/* After TXFLR fills up, clear it by reading available data */
464 		while (received < requested - lowat) {
465 			burst = MIN((int)len - received,
466 			    reg_read(sc, IG4_REG_RXFLR) & IG4_FIFOLVL_MASK);
467 			if (burst > 0) {
468 				while (burst--)
469 					buf[received++] = 0xFF &
470 					    reg_read(sc, IG4_REG_DATA_CMD);
471 			} else {
472 				error = wait_intr(sc, IG4_INTR_RX_FULL);
473 				if (error)
474 					goto out;
475 			}
476 		}
477 	}
478 out:
479 	return (error);
480 }
481 
482 static int
483 ig4iic_write(ig4iic_softc_t *sc, uint8_t *buf, uint16_t len,
484     bool repeated_start, bool stop)
485 {
486 	uint32_t cmd;
487 	int sent = 0;
488 	int burst, target;
489 	int error;
490 	bool lowat_set = false;
491 
492 	if (len == 0)
493 		return (0);
494 
495 	while (sent < len) {
496 		burst = sc->cfg.txfifo_depth -
497 		    (reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
498 		target = MIN(sent + burst, (int)len);
499 		/* Leave some data queued to maintain the hardware pipeline */
500 		if (!lowat_set && target != len) {
501 			lowat_set = true;
502 			reg_write(sc, IG4_REG_TX_TL, IG4_FIFO_LOWAT);
503 		}
504 		while(sent < target) {
505 			cmd = buf[sent];
506 			if (repeated_start && sent == 0)
507 				cmd |= IG4_DATA_RESTART;
508 			if (stop && sent == len - 1)
509 				cmd |= IG4_DATA_STOP;
510 			reg_write(sc, IG4_REG_DATA_CMD, cmd);
511 			sent++;
512 		}
513 		if (sent < len) {
514 			error = wait_intr(sc, IG4_INTR_TX_EMPTY);
515 			if (error)
516 				break;
517 		}
518 	}
519 	if (lowat_set)
520 		reg_write(sc, IG4_REG_TX_TL, 0);
521 
522 	return (error);
523 }
524 
525 int
526 ig4iic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
527 {
528 	ig4iic_softc_t *sc = device_get_softc(dev);
529 	const char *reason = NULL;
530 	uint32_t i;
531 	int error;
532 	int unit;
533 	bool rpstart;
534 	bool stop;
535 	bool allocated;
536 
537 	/*
538 	 * The hardware interface imposes limits on allowed I2C messages.
539 	 * It is not possible to explicitly send a start or stop.
540 	 * They are automatically sent (or not sent, depending on the
541 	 * configuration) when a data byte is transferred.
542 	 * For this reason it's impossible to send a message with no data
543 	 * at all (like an SMBus quick message).
544 	 * The start condition is automatically generated after the stop
545 	 * condition, so it's impossible to not have a start after a stop.
546 	 * The repeated start condition is automatically sent if a change
547 	 * of the transfer direction happens, so it's impossible to have
548 	 * a change of direction without a (repeated) start.
549 	 * The repeated start can be forced even without the change of
550 	 * direction.
551 	 * Changing the target slave address requires resetting the hardware
552 	 * state, so it's impossible to do that without the stop followed
553 	 * by the start.
554 	 */
555 	for (i = 0; i < nmsgs; i++) {
556 #if 0
557 		if (i == 0 && (msgs[i].flags & IIC_M_NOSTART) != 0) {
558 			reason = "first message without start";
559 			break;
560 		}
561 		if (i == nmsgs - 1 && (msgs[i].flags & IIC_M_NOSTOP) != 0) {
562 			reason = "last message without stop";
563 			break;
564 		}
565 #endif
566 		if (msgs[i].len == 0) {
567 			reason = "message with no data";
568 			break;
569 		}
570 		if (i > 0) {
571 			if ((msgs[i].flags & IIC_M_NOSTART) != 0 &&
572 			    (msgs[i - 1].flags & IIC_M_NOSTOP) == 0) {
573 				reason = "stop not followed by start";
574 				break;
575 			}
576 			if ((msgs[i - 1].flags & IIC_M_NOSTOP) != 0 &&
577 			    msgs[i].slave != msgs[i - 1].slave) {
578 				reason = "change of slave without stop";
579 				break;
580 			}
581 			if ((msgs[i].flags & IIC_M_NOSTART) != 0 &&
582 			    (msgs[i].flags & IIC_M_RD) !=
583 			    (msgs[i - 1].flags & IIC_M_RD)) {
584 				reason = "change of direction without repeated"
585 				    " start";
586 				break;
587 			}
588 		}
589 	}
590 	if (reason != NULL) {
591 		if (bootverbose)
592 			device_printf(dev, "%s\n", reason);
593 		return (IIC_ENOTSUPP);
594 	}
595 
596 	/* Check if device is already allocated with iicbus_request_bus() */
597 	allocated = sx_xlocked(&sc->call_lock) != 0;
598 	if (!allocated)
599 		sx_xlock(&sc->call_lock);
600 
601 	/* Debugging - dump registers. */
602 	if (ig4_dump) {
603 		unit = device_get_unit(dev);
604 		if (ig4_dump & (1 << unit)) {
605 			ig4_dump &= ~(1 << unit);
606 			ig4iic_dump(sc);
607 		}
608 	}
609 
610 	/*
611 	 * Clear any previous abort condition that may have been holding
612 	 * the txfifo in reset.
613 	 */
614 	reg_read(sc, IG4_REG_CLR_TX_ABORT);
615 
616 	rpstart = false;
617 	error = 0;
618 	for (i = 0; i < nmsgs; i++) {
619 		if ((msgs[i].flags & IIC_M_NOSTART) == 0) {
620 			error = ig4iic_xfer_start(sc, msgs[i].slave, rpstart);
621 		} else {
622 			if (!sc->slave_valid ||
623 			    (msgs[i].slave >> 1) != sc->last_slave) {
624 				device_printf(dev, "start condition suppressed"
625 				    "but slave address is not set up");
626 				error = EINVAL;
627 				break;
628 			}
629 			rpstart = false;
630 		}
631 		if (error != 0)
632 			break;
633 
634 		stop = (msgs[i].flags & IIC_M_NOSTOP) == 0;
635 		if (msgs[i].flags & IIC_M_RD)
636 			error = ig4iic_read(sc, msgs[i].buf, msgs[i].len,
637 			    rpstart, stop);
638 		else
639 			error = ig4iic_write(sc, msgs[i].buf, msgs[i].len,
640 			    rpstart, stop);
641 
642 		/* Wait for error or stop condition occurred on the I2C bus */
643 		if (stop && error == 0) {
644 			error = wait_intr(sc, IG4_INTR_STOP_DET);
645 			if (error == 0)
646 				reg_read(sc, IG4_REG_CLR_INTR);
647 		}
648 
649 		if (error != 0) {
650 			/*
651 			 * Send STOP condition if it's not done yet and flush
652 			 * both FIFOs. Do a controller soft reset if transfer
653 			 * abort is failed.
654 			 */
655 			if (ig4iic_xfer_is_started(sc) &&
656 			    ig4iic_xfer_abort(sc) != 0) {
657 				device_printf(sc->dev, "Failed to abort "
658 				    "transfer. Do the controller reset.\n");
659 				ig4iic_set_config(sc, true);
660 			} else {
661 				while (reg_read(sc, IG4_REG_I2C_STA) &
662 				    IG4_STATUS_RX_NOTEMPTY)
663 					reg_read(sc, IG4_REG_DATA_CMD);
664 				reg_read(sc, IG4_REG_TX_ABRT_SOURCE);
665 				reg_read(sc, IG4_REG_CLR_INTR);
666 			}
667 			break;
668 		}
669 
670 		rpstart = !stop;
671 	}
672 
673 	if (!allocated)
674 		sx_unlock(&sc->call_lock);
675 	return (error);
676 }
677 
678 int
679 ig4iic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
680 {
681 	ig4iic_softc_t *sc = device_get_softc(dev);
682 	bool allocated;
683 
684 	allocated = sx_xlocked(&sc->call_lock) != 0;
685 	if (!allocated)
686 		sx_xlock(&sc->call_lock);
687 
688 	/* TODO handle speed configuration? */
689 	if (oldaddr != NULL)
690 		*oldaddr = sc->last_slave << 1;
691 	set_slave_addr(sc, addr >> 1);
692 	if (addr == IIC_UNKNOWN)
693 		sc->slave_valid = false;
694 
695 	if (!allocated)
696 		sx_unlock(&sc->call_lock);
697 	return (0);
698 }
699 
700 int
701 ig4iic_callback(device_t dev, int index, caddr_t data)
702 {
703 	ig4iic_softc_t *sc = device_get_softc(dev);
704 	int error = 0;
705 	int how;
706 
707 	switch (index) {
708 	case IIC_REQUEST_BUS:
709 		/* force polling if ig4iic is requested with IIC_DONTWAIT */
710 		how = *(int *)data;
711 		if ((how & IIC_WAIT) == 0) {
712 			if (sx_try_xlock(&sc->call_lock) == 0)
713 				error = IIC_EBUSBSY;
714 			else
715 				sc->poll = true;
716 		} else
717 			sx_xlock(&sc->call_lock);
718 		break;
719 
720 	case IIC_RELEASE_BUS:
721 		sc->poll = false;
722 		sx_unlock(&sc->call_lock);
723 		break;
724 
725 	default:
726 		error = errno2iic(EINVAL);
727 	}
728 
729 	return (error);
730 }
731 
732 /*
733  * Clock register values can be calculated with following rough equations:
734  * SCL_HCNT = ceil(IC clock rate * tHIGH)
735  * SCL_LCNT = ceil(IC clock rate * tLOW)
736  * SDA_HOLD = ceil(IC clock rate * SDA hold time)
737  * Precise equations take signal's falling, rising and spike suppression
738  * times in to account. They can be found in Synopsys or Intel documentation.
739  *
740  * Here we snarf formulas and defaults from Linux driver to be able to use
741  * timing values provided by Intel LPSS driver "as is".
742  */
743 static int
744 ig4iic_clk_params(const struct ig4_hw *hw, int speed,
745     uint16_t *scl_hcnt, uint16_t *scl_lcnt, uint16_t *sda_hold)
746 {
747 	uint32_t thigh, tlow, tf_max;	/* nsec */
748 	uint32_t sda_fall_time;		/* nsec */
749         uint32_t scl_fall_time;		/* nsec */
750 
751 	switch (speed) {
752 	case IG4_CTL_SPEED_STD:
753 		thigh = IG4_SPEED_STD_THIGH;
754 		tlow = IG4_SPEED_STD_TLOW;
755 		tf_max = IG4_SPEED_STD_TF_MAX;
756 		break;
757 
758 	case IG4_CTL_SPEED_FAST:
759 		thigh = IG4_SPEED_FAST_THIGH;
760 		tlow = IG4_SPEED_FAST_TLOW;
761 		tf_max = IG4_SPEED_FAST_TF_MAX;
762 		break;
763 
764 	default:
765 		return (EINVAL);
766 	}
767 
768 	/* Use slowest falling time defaults to be on the safe side */
769 	sda_fall_time = hw->sda_fall_time == 0 ? tf_max : hw->sda_fall_time;
770 	*scl_hcnt = (uint16_t)
771 	    ((hw->ic_clock_rate * (thigh + sda_fall_time) + 500) / 1000 - 3);
772 
773 	scl_fall_time = hw->scl_fall_time == 0 ? tf_max : hw->scl_fall_time;
774 	*scl_lcnt = (uint16_t)
775 	    ((hw->ic_clock_rate * (tlow + scl_fall_time) + 500) / 1000 - 1);
776 
777 	/*
778 	 * There is no "known good" default value for tHD;DAT so keep SDA_HOLD
779 	 * intact if sda_hold_time value is not provided.
780 	 */
781 	if (hw->sda_hold_time != 0)
782 		*sda_hold = (uint16_t)
783 		    ((hw->ic_clock_rate * hw->sda_hold_time + 500) / 1000);
784 
785 	return (0);
786 }
787 
788 #ifdef DEV_ACPI
789 static ACPI_STATUS
790 ig4iic_acpi_params(ACPI_HANDLE handle, char *method,
791     uint16_t *scl_hcnt, uint16_t *scl_lcnt, uint16_t *sda_hold)
792 {
793 	ACPI_BUFFER buf;
794 	ACPI_OBJECT *obj, *elems;
795 	ACPI_STATUS status;
796 
797 	buf.Pointer = NULL;
798 	buf.Length = ACPI_ALLOCATE_BUFFER;
799 
800 	status = AcpiEvaluateObject(handle, method, NULL, &buf);
801 	if (ACPI_FAILURE(status))
802 		return (status);
803 
804 	status = AE_TYPE;
805 	obj = (ACPI_OBJECT *)buf.Pointer;
806 	if (obj->Type == ACPI_TYPE_PACKAGE && obj->Package.Count == 3) {
807 		elems = obj->Package.Elements;
808 		*scl_hcnt = elems[0].Integer.Value & IG4_SCL_CLOCK_MASK;
809 		*scl_lcnt = elems[1].Integer.Value & IG4_SCL_CLOCK_MASK;
810 		*sda_hold = elems[2].Integer.Value & IG4_SDA_TX_HOLD_MASK;
811 		status = AE_OK;
812 	}
813 
814 	AcpiOsFree(obj);
815 
816 	return (status);
817 }
818 #endif /* DEV_ACPI */
819 
820 static void
821 ig4iic_get_config(ig4iic_softc_t *sc)
822 {
823 	const struct ig4_hw *hw;
824 	uint32_t v;
825 #ifdef DEV_ACPI
826 	ACPI_HANDLE handle;
827 #endif
828 	/* Fetch default hardware config from controller */
829 	sc->cfg.version = reg_read(sc, IG4_REG_COMP_VER);
830 	sc->cfg.bus_speed = reg_read(sc, IG4_REG_CTL) & IG4_CTL_SPEED_MASK;
831 	sc->cfg.ss_scl_hcnt =
832 	    reg_read(sc, IG4_REG_SS_SCL_HCNT) & IG4_SCL_CLOCK_MASK;
833 	sc->cfg.ss_scl_lcnt =
834 	    reg_read(sc, IG4_REG_SS_SCL_LCNT) & IG4_SCL_CLOCK_MASK;
835 	sc->cfg.fs_scl_hcnt =
836 	    reg_read(sc, IG4_REG_FS_SCL_HCNT) & IG4_SCL_CLOCK_MASK;
837 	sc->cfg.fs_scl_lcnt =
838 	    reg_read(sc, IG4_REG_FS_SCL_LCNT) & IG4_SCL_CLOCK_MASK;
839 	sc->cfg.ss_sda_hold = sc->cfg.fs_sda_hold =
840 	    reg_read(sc, IG4_REG_SDA_HOLD) & IG4_SDA_TX_HOLD_MASK;
841 
842 	if (sc->cfg.bus_speed != IG4_CTL_SPEED_STD)
843 		sc->cfg.bus_speed = IG4_CTL_SPEED_FAST;
844 
845 	/* REG_COMP_PARAM1 is not documented in latest Intel specs */
846 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
847 		v = reg_read(sc, IG4_REG_COMP_PARAM1);
848 		if (IG4_PARAM1_TXFIFO_DEPTH(v) != 0)
849 			sc->cfg.txfifo_depth = IG4_PARAM1_TXFIFO_DEPTH(v);
850 		if (IG4_PARAM1_RXFIFO_DEPTH(v) != 0)
851 			sc->cfg.rxfifo_depth = IG4_PARAM1_RXFIFO_DEPTH(v);
852 	} else {
853 		/*
854 		 * Hardware does not allow FIFO Threshold Levels value to be
855 		 * set larger than the depth of the buffer. If an attempt is
856 		 * made to do that, the actual value set will be the maximum
857 		 * depth of the buffer.
858 		 */
859 		v = reg_read(sc, IG4_REG_TX_TL);
860 		reg_write(sc, IG4_REG_TX_TL, v | IG4_FIFO_MASK);
861 		sc->cfg.txfifo_depth =
862 		    (reg_read(sc, IG4_REG_TX_TL) & IG4_FIFO_MASK) + 1;
863 		reg_write(sc, IG4_REG_TX_TL, v);
864 		v = reg_read(sc, IG4_REG_RX_TL);
865 		reg_write(sc, IG4_REG_RX_TL, v | IG4_FIFO_MASK);
866 		sc->cfg.rxfifo_depth =
867 		    (reg_read(sc, IG4_REG_RX_TL) & IG4_FIFO_MASK) + 1;
868 		reg_write(sc, IG4_REG_RX_TL, v);
869 	}
870 
871 	/* Override hardware config with IC_clock-based counter values */
872 	if (ig4_timings < 2 && sc->version < nitems(ig4iic_hw)) {
873 		hw = &ig4iic_hw[sc->version];
874 		sc->cfg.bus_speed = IG4_CTL_SPEED_FAST;
875 		ig4iic_clk_params(hw, IG4_CTL_SPEED_STD, &sc->cfg.ss_scl_hcnt,
876 		    &sc->cfg.ss_scl_lcnt, &sc->cfg.ss_sda_hold);
877 		ig4iic_clk_params(hw, IG4_CTL_SPEED_FAST, &sc->cfg.fs_scl_hcnt,
878 		    &sc->cfg.fs_scl_lcnt, &sc->cfg.fs_sda_hold);
879 		if (hw->txfifo_depth != 0)
880 			sc->cfg.txfifo_depth = hw->txfifo_depth;
881 		if (hw->rxfifo_depth != 0)
882 			sc->cfg.rxfifo_depth = hw->rxfifo_depth;
883 	} else if (ig4_timings == 2) {
884 		/*
885 		 * Timings of original ig4 driver:
886 		 * Program based on a 25000 Hz clock.  This is a bit of a
887 		 * hack (obviously).  The defaults are 400 and 470 for standard
888 		 * and 60 and 130 for fast.  The defaults for standard fail
889 		 * utterly (presumably cause an abort) because the clock time
890 		 * is ~18.8ms by default.  This brings it down to ~4ms.
891 		 */
892 		sc->cfg.bus_speed = IG4_CTL_SPEED_STD;
893 		sc->cfg.ss_scl_hcnt = sc->cfg.fs_scl_hcnt = 100;
894 		sc->cfg.ss_scl_lcnt = sc->cfg.fs_scl_lcnt = 125;
895 		if (sc->version == IG4_SKYLAKE)
896 			sc->cfg.ss_sda_hold = sc->cfg.fs_sda_hold = 28;
897 	}
898 
899 #ifdef DEV_ACPI
900 	/* Evaluate SSCN and FMCN ACPI methods to fetch timings */
901 	if (ig4_timings == 0 && (handle = acpi_get_handle(sc->dev)) != NULL) {
902 		ig4iic_acpi_params(handle, "SSCN", &sc->cfg.ss_scl_hcnt,
903 		    &sc->cfg.ss_scl_lcnt, &sc->cfg.ss_sda_hold);
904 		ig4iic_acpi_params(handle, "FMCN", &sc->cfg.fs_scl_hcnt,
905 		    &sc->cfg.fs_scl_lcnt, &sc->cfg.fs_sda_hold);
906 	}
907 #endif
908 
909 	if (bootverbose) {
910 		device_printf(sc->dev, "Controller parameters:\n");
911 		printf("  Speed: %s\n",
912 		    sc->cfg.bus_speed == IG4_CTL_SPEED_STD ? "Std" : "Fast");
913 		printf("  Regs:  HCNT  :LCNT  :SDAHLD\n");
914 		printf("  Std:   0x%04hx:0x%04hx:0x%04hx\n",
915 		    sc->cfg.ss_scl_hcnt, sc->cfg.ss_scl_lcnt,
916 		    sc->cfg.ss_sda_hold);
917 		printf("  Fast:  0x%04hx:0x%04hx:0x%04hx\n",
918 		    sc->cfg.fs_scl_hcnt, sc->cfg.fs_scl_lcnt,
919 		    sc->cfg.fs_sda_hold);
920 		printf("  FIFO:  RX:0x%04x: TX:0x%04x\n",
921 		    sc->cfg.rxfifo_depth, sc->cfg.txfifo_depth);
922 	}
923 }
924 
925 static int
926 ig4iic_set_config(ig4iic_softc_t *sc, bool reset)
927 {
928 	uint32_t v;
929 
930 	v = reg_read(sc, IG4_REG_DEVIDLE_CTRL);
931 	if (IG4_HAS_ADDREGS(sc->version) && (v & IG4_RESTORE_REQUIRED)) {
932 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, IG4_DEVICE_IDLE | IG4_RESTORE_REQUIRED);
933 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, 0);
934 		pause("i2crst", 1);
935 		reset = true;
936 	}
937 
938 	if ((sc->version == IG4_HASWELL || sc->version == IG4_ATOM) && reset) {
939 		reg_write(sc, IG4_REG_RESETS_HSW, IG4_RESETS_ASSERT_HSW);
940 		reg_write(sc, IG4_REG_RESETS_HSW, IG4_RESETS_DEASSERT_HSW);
941 	} else if (IG4_HAS_ADDREGS(sc->version) && reset) {
942 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_ASSERT_SKL);
943 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_DEASSERT_SKL);
944 	}
945 
946 	if (sc->version == IG4_ATOM)
947 		v = reg_read(sc, IG4_REG_COMP_TYPE);
948 
949 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
950 		v = reg_read(sc, IG4_REG_COMP_PARAM1);
951 		v = reg_read(sc, IG4_REG_GENERAL);
952 		/*
953 		 * The content of IG4_REG_GENERAL is different for each
954 		 * controller version.
955 		 */
956 		if (sc->version == IG4_HASWELL &&
957 		    (v & IG4_GENERAL_SWMODE) == 0) {
958 			v |= IG4_GENERAL_SWMODE;
959 			reg_write(sc, IG4_REG_GENERAL, v);
960 			v = reg_read(sc, IG4_REG_GENERAL);
961 		}
962 	}
963 
964 	if (sc->version == IG4_HASWELL) {
965 		v = reg_read(sc, IG4_REG_SW_LTR_VALUE);
966 		v = reg_read(sc, IG4_REG_AUTO_LTR_VALUE);
967 	} else if (IG4_HAS_ADDREGS(sc->version)) {
968 		v = reg_read(sc, IG4_REG_ACTIVE_LTR_VALUE);
969 		v = reg_read(sc, IG4_REG_IDLE_LTR_VALUE);
970 	}
971 
972 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
973 		v = reg_read(sc, IG4_REG_COMP_VER);
974 		if (v < IG4_COMP_MIN_VER)
975 			return(ENXIO);
976 	}
977 
978 	if (set_controller(sc, 0)) {
979 		device_printf(sc->dev, "controller error during attach-1\n");
980 		return (ENXIO);
981 	}
982 
983 	reg_read(sc, IG4_REG_CLR_INTR);
984 	reg_write(sc, IG4_REG_INTR_MASK, 0);
985 	sc->intr_mask = 0;
986 
987 	reg_write(sc, IG4_REG_SS_SCL_HCNT, sc->cfg.ss_scl_hcnt);
988 	reg_write(sc, IG4_REG_SS_SCL_LCNT, sc->cfg.ss_scl_lcnt);
989 	reg_write(sc, IG4_REG_FS_SCL_HCNT, sc->cfg.fs_scl_hcnt);
990 	reg_write(sc, IG4_REG_FS_SCL_LCNT, sc->cfg.fs_scl_lcnt);
991 	reg_write(sc, IG4_REG_SDA_HOLD,
992 	    (sc->cfg.bus_speed  & IG4_CTL_SPEED_MASK) == IG4_CTL_SPEED_STD ?
993 	      sc->cfg.ss_sda_hold : sc->cfg.fs_sda_hold);
994 
995 	/*
996 	 * Use a threshold of 1 so we get interrupted on each character,
997 	 * allowing us to use mtx_sleep() in our poll code.  Not perfect
998 	 * but this is better than using DELAY() for receiving data.
999 	 *
1000 	 * See ig4_var.h for details on interrupt handler synchronization.
1001 	 */
1002 	reg_write(sc, IG4_REG_RX_TL, 0);
1003 	reg_write(sc, IG4_REG_TX_TL, 0);
1004 
1005 	reg_write(sc, IG4_REG_CTL,
1006 		  IG4_CTL_MASTER |
1007 		  IG4_CTL_SLAVE_DISABLE |
1008 		  IG4_CTL_RESTARTEN |
1009 		  (sc->cfg.bus_speed & IG4_CTL_SPEED_MASK));
1010 
1011 	/* Force setting of the target address on the next transfer */
1012 	sc->slave_valid = 0;
1013 
1014 	return (0);
1015 }
1016 
1017 /*
1018  * Called from ig4iic_pci_attach/detach()
1019  */
1020 int
1021 ig4iic_attach(ig4iic_softc_t *sc)
1022 {
1023 	int error;
1024 
1025 	mtx_init(&sc->io_lock, "IG4 I/O lock", NULL, MTX_SPIN);
1026 	sx_init(&sc->call_lock, "IG4 call lock");
1027 
1028 	ig4iic_get_config(sc);
1029 
1030 	error = ig4iic_set_config(sc, IG4_HAS_ADDREGS(sc->version));
1031 	if (error)
1032 		goto done;
1033 
1034 	sc->iicbus = device_add_child(sc->dev, "iicbus", -1);
1035 	if (sc->iicbus == NULL) {
1036 		device_printf(sc->dev, "iicbus driver not found\n");
1037 		error = ENXIO;
1038 		goto done;
1039 	}
1040 
1041 	if (set_controller(sc, IG4_I2C_ENABLE)) {
1042 		device_printf(sc->dev, "controller error during attach-2\n");
1043 		error = ENXIO;
1044 		goto done;
1045 	}
1046 	if (set_controller(sc, 0)) {
1047 		device_printf(sc->dev, "controller error during attach-3\n");
1048 		error = ENXIO;
1049 		goto done;
1050 	}
1051 	error = bus_setup_intr(sc->dev, sc->intr_res, INTR_TYPE_MISC | INTR_MPSAFE,
1052 			       ig4iic_intr, NULL, sc, &sc->intr_handle);
1053 	if (error) {
1054 		device_printf(sc->dev,
1055 			      "Unable to setup irq: error %d\n", error);
1056 	}
1057 
1058 	error = bus_generic_attach(sc->dev);
1059 	if (error) {
1060 		device_printf(sc->dev,
1061 			      "failed to attach child: error %d\n", error);
1062 	}
1063 
1064 done:
1065 	return (error);
1066 }
1067 
1068 int
1069 ig4iic_detach(ig4iic_softc_t *sc)
1070 {
1071 	int error;
1072 
1073 	if (device_is_attached(sc->dev)) {
1074 		error = bus_generic_detach(sc->dev);
1075 		if (error)
1076 			return (error);
1077 	}
1078 	if (sc->iicbus)
1079 		device_delete_child(sc->dev, sc->iicbus);
1080 	if (sc->intr_handle)
1081 		bus_teardown_intr(sc->dev, sc->intr_res, sc->intr_handle);
1082 
1083 	sx_xlock(&sc->call_lock);
1084 
1085 	sc->iicbus = NULL;
1086 	sc->intr_handle = NULL;
1087 	reg_write(sc, IG4_REG_INTR_MASK, 0);
1088 	set_controller(sc, 0);
1089 
1090 	sx_xunlock(&sc->call_lock);
1091 
1092 	mtx_destroy(&sc->io_lock);
1093 	sx_destroy(&sc->call_lock);
1094 
1095 	return (0);
1096 }
1097 
1098 int
1099 ig4iic_suspend(ig4iic_softc_t *sc)
1100 {
1101 	int error;
1102 
1103 	/* suspend all children */
1104 	error = bus_generic_suspend(sc->dev);
1105 
1106 	sx_xlock(&sc->call_lock);
1107 	set_controller(sc, 0);
1108 	if (IG4_HAS_ADDREGS(sc->version)) {
1109 		/*
1110 		 * Place the device in the idle state, just to be safe
1111 		 */
1112 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, IG4_DEVICE_IDLE);
1113 		/*
1114 		 * Controller can become dysfunctional if I2C lines are pulled
1115 		 * down when suspend procedure turns off power to I2C device.
1116 		 * Place device in the reset state to avoid this.
1117 		 */
1118 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_ASSERT_SKL);
1119 	}
1120 	sx_xunlock(&sc->call_lock);
1121 
1122 	return (error);
1123 }
1124 
1125 int ig4iic_resume(ig4iic_softc_t *sc)
1126 {
1127 	int error;
1128 
1129 	sx_xlock(&sc->call_lock);
1130 	if (ig4iic_set_config(sc, IG4_HAS_ADDREGS(sc->version)))
1131 		device_printf(sc->dev, "controller error during resume\n");
1132 	sx_xunlock(&sc->call_lock);
1133 
1134 	error = bus_generic_resume(sc->dev);
1135 
1136 	return (error);
1137 }
1138 
1139 /*
1140  * Interrupt Operation, see ig4_var.h for locking semantics.
1141  */
1142 static int
1143 ig4iic_intr(void *cookie)
1144 {
1145 	ig4iic_softc_t *sc = cookie;
1146 	int retval = FILTER_STRAY;
1147 
1148 	mtx_lock_spin(&sc->io_lock);
1149 	/* Ignore stray interrupts */
1150 	if (sc->intr_mask != 0 && reg_read(sc, IG4_REG_INTR_STAT) != 0) {
1151 		/* Interrupt bits are cleared in wait_intr() loop */
1152 		ig4iic_set_intr_mask(sc, 0);
1153 		wakeup(sc);
1154 		retval = FILTER_HANDLED;
1155 	}
1156 	mtx_unlock_spin(&sc->io_lock);
1157 
1158 	return (retval);
1159 }
1160 
1161 #define REGDUMP(sc, reg)	\
1162 	device_printf(sc->dev, "  %-23s %08x\n", #reg, reg_read(sc, reg))
1163 
1164 static void
1165 ig4iic_dump(ig4iic_softc_t *sc)
1166 {
1167 	device_printf(sc->dev, "ig4iic register dump:\n");
1168 	REGDUMP(sc, IG4_REG_CTL);
1169 	REGDUMP(sc, IG4_REG_TAR_ADD);
1170 	REGDUMP(sc, IG4_REG_SS_SCL_HCNT);
1171 	REGDUMP(sc, IG4_REG_SS_SCL_LCNT);
1172 	REGDUMP(sc, IG4_REG_FS_SCL_HCNT);
1173 	REGDUMP(sc, IG4_REG_FS_SCL_LCNT);
1174 	REGDUMP(sc, IG4_REG_INTR_STAT);
1175 	REGDUMP(sc, IG4_REG_INTR_MASK);
1176 	REGDUMP(sc, IG4_REG_RAW_INTR_STAT);
1177 	REGDUMP(sc, IG4_REG_RX_TL);
1178 	REGDUMP(sc, IG4_REG_TX_TL);
1179 	REGDUMP(sc, IG4_REG_I2C_EN);
1180 	REGDUMP(sc, IG4_REG_I2C_STA);
1181 	REGDUMP(sc, IG4_REG_TXFLR);
1182 	REGDUMP(sc, IG4_REG_RXFLR);
1183 	REGDUMP(sc, IG4_REG_SDA_HOLD);
1184 	REGDUMP(sc, IG4_REG_TX_ABRT_SOURCE);
1185 	REGDUMP(sc, IG4_REG_SLV_DATA_NACK);
1186 	REGDUMP(sc, IG4_REG_DMA_CTRL);
1187 	REGDUMP(sc, IG4_REG_DMA_TDLR);
1188 	REGDUMP(sc, IG4_REG_DMA_RDLR);
1189 	REGDUMP(sc, IG4_REG_SDA_SETUP);
1190 	REGDUMP(sc, IG4_REG_ENABLE_STATUS);
1191 	REGDUMP(sc, IG4_REG_COMP_PARAM1);
1192 	REGDUMP(sc, IG4_REG_COMP_VER);
1193 	if (sc->version == IG4_ATOM) {
1194 		REGDUMP(sc, IG4_REG_COMP_TYPE);
1195 		REGDUMP(sc, IG4_REG_CLK_PARMS);
1196 	}
1197 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
1198 		REGDUMP(sc, IG4_REG_RESETS_HSW);
1199 		REGDUMP(sc, IG4_REG_GENERAL);
1200 	} else if (sc->version == IG4_SKYLAKE) {
1201 		REGDUMP(sc, IG4_REG_RESETS_SKL);
1202 	}
1203 	if (sc->version == IG4_HASWELL) {
1204 		REGDUMP(sc, IG4_REG_SW_LTR_VALUE);
1205 		REGDUMP(sc, IG4_REG_AUTO_LTR_VALUE);
1206 	} else if (IG4_HAS_ADDREGS(sc->version)) {
1207 		REGDUMP(sc, IG4_REG_ACTIVE_LTR_VALUE);
1208 		REGDUMP(sc, IG4_REG_IDLE_LTR_VALUE);
1209 	}
1210 }
1211 #undef REGDUMP
1212 
1213 devclass_t ig4iic_devclass;
1214 
1215 DRIVER_MODULE(iicbus, ig4iic, iicbus_driver, iicbus_devclass, NULL, NULL);
1216 #ifdef DEV_ACPI
1217 DRIVER_MODULE(acpi_iicbus, ig4iic, acpi_iicbus_driver, iicbus_devclass, NULL,
1218     NULL);
1219 #endif
1220 MODULE_DEPEND(ig4iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
1221 MODULE_VERSION(ig4iic, 1);
1222