xref: /freebsd/sys/dev/ichiic/ig4_iic.c (revision a2f733abcff64628b7771a47089628b7327a88bd)
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 /*
38  * Intel fourth generation mobile cpus integrated I2C device.
39  *
40  * See ig4_reg.h for datasheet reference and notes.
41  * See ig4_var.h for locking semantics.
42  */
43 
44 #include "opt_acpi.h"
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/kernel.h>
49 #include <sys/module.h>
50 #include <sys/errno.h>
51 #include <sys/kdb.h>
52 #include <sys/lock.h>
53 #include <sys/mutex.h>
54 #include <sys/proc.h>
55 #include <sys/sx.h>
56 #include <sys/syslog.h>
57 #include <sys/bus.h>
58 #include <sys/sysctl.h>
59 
60 #include <machine/bus.h>
61 #include <sys/rman.h>
62 
63 #ifdef DEV_ACPI
64 #include <contrib/dev/acpica/include/acpi.h>
65 #include <contrib/dev/acpica/include/accommon.h>
66 #include <dev/acpica/acpivar.h>
67 #endif
68 
69 #include <dev/iicbus/iicbus.h>
70 #include <dev/iicbus/iiconf.h>
71 
72 #include <dev/ichiic/ig4_reg.h>
73 #include <dev/ichiic/ig4_var.h>
74 
75 #define DO_POLL(sc)	(cold || kdb_active || SCHEDULER_STOPPED() || sc->poll)
76 
77 /*
78  * tLOW, tHIGH periods of the SCL clock and maximal falling time of both
79  * lines are taken from I2C specifications.
80  */
81 #define	IG4_SPEED_STD_THIGH	4000	/* nsec */
82 #define	IG4_SPEED_STD_TLOW	4700	/* nsec */
83 #define	IG4_SPEED_STD_TF_MAX	300	/* nsec */
84 #define	IG4_SPEED_FAST_THIGH	600	/* nsec */
85 #define	IG4_SPEED_FAST_TLOW	1300	/* nsec */
86 #define	IG4_SPEED_FAST_TF_MAX	300	/* nsec */
87 
88 /*
89  * Ig4 hardware parameters except Haswell are taken from intel_lpss driver
90  */
91 static const struct ig4_hw ig4iic_hw[] = {
92 	[IG4_EMAG] = {
93 		.ic_clock_rate = 100,	/* MHz */
94 	},
95 	[IG4_HASWELL] = {
96 		.ic_clock_rate = 100,	/* MHz */
97 		.sda_hold_time = 90,	/* nsec */
98 		.txfifo_depth = 32,
99 		.rxfifo_depth = 32,
100 	},
101 	[IG4_ATOM] = {
102 		.ic_clock_rate = 100,
103 		.sda_fall_time = 280,
104 		.scl_fall_time = 240,
105 		.sda_hold_time = 60,
106 		.txfifo_depth = 32,
107 		.rxfifo_depth = 32,
108 	},
109 	[IG4_SKYLAKE] = {
110 		.ic_clock_rate = 120,
111 		.sda_hold_time = 230,
112 	},
113 	[IG4_APL] = {
114 		.ic_clock_rate = 133,
115 		.sda_fall_time = 171,
116 		.scl_fall_time = 208,
117 		.sda_hold_time = 207,
118 	},
119 	[IG4_CANNONLAKE] = {
120 		.ic_clock_rate = 216,
121 		.sda_hold_time = 230,
122 	},
123 	[IG4_TIGERLAKE] = {
124 		.ic_clock_rate = 133,
125 		.sda_fall_time = 171,
126 		.scl_fall_time = 208,
127 		.sda_hold_time = 42,
128 	},
129 	[IG4_GEMINILAKE] = {
130 		.ic_clock_rate = 133,
131 		.sda_fall_time = 171,
132 		.scl_fall_time = 290,
133 		.sda_hold_time = 313,
134 	},
135 };
136 
137 static int ig4iic_set_config(ig4iic_softc_t *sc, bool reset);
138 static driver_filter_t ig4iic_intr;
139 static void ig4iic_dump(ig4iic_softc_t *sc);
140 
141 static int ig4_dump;
142 SYSCTL_INT(_debug, OID_AUTO, ig4_dump, CTLFLAG_RW,
143 	   &ig4_dump, 0, "Dump controller registers");
144 
145 /*
146  * Clock registers initialization control
147  * 0 - Try read clock registers from ACPI and fallback to p.1.
148  * 1 - Calculate values based on controller type (IC clock rate).
149  * 2 - Use values inherited from DragonflyBSD driver (old behavior).
150  * 3 - Keep clock registers intact.
151  */
152 static int ig4_timings;
153 SYSCTL_INT(_debug, OID_AUTO, ig4_timings, CTLFLAG_RDTUN, &ig4_timings, 0,
154     "Controller timings 0=ACPI, 1=predefined, 2=legacy, 3=do not change");
155 
156 /*
157  * Low-level inline support functions
158  */
159 static __inline void
160 reg_write(ig4iic_softc_t *sc, uint32_t reg, uint32_t value)
161 {
162 	bus_write_4(sc->regs_res, reg, value);
163 	bus_barrier(sc->regs_res, reg, 4, BUS_SPACE_BARRIER_WRITE);
164 }
165 
166 static __inline uint32_t
167 reg_read(ig4iic_softc_t *sc, uint32_t reg)
168 {
169 	uint32_t value;
170 
171 	bus_barrier(sc->regs_res, reg, 4, BUS_SPACE_BARRIER_READ);
172 	value = bus_read_4(sc->regs_res, reg);
173 	return (value);
174 }
175 
176 static void
177 ig4iic_set_intr_mask(ig4iic_softc_t *sc, uint32_t val)
178 {
179 	if (sc->intr_mask != val) {
180 		reg_write(sc, IG4_REG_INTR_MASK, val);
181 		sc->intr_mask = val;
182 	}
183 }
184 
185 static int
186 intrstat2iic(ig4iic_softc_t *sc, uint32_t val)
187 {
188 	uint32_t src;
189 
190 	if (val & IG4_INTR_RX_UNDER)
191 		reg_read(sc, IG4_REG_CLR_RX_UNDER);
192 	if (val & IG4_INTR_RX_OVER)
193 		reg_read(sc, IG4_REG_CLR_RX_OVER);
194 	if (val & IG4_INTR_TX_OVER)
195 		reg_read(sc, IG4_REG_CLR_TX_OVER);
196 
197 	if (val & IG4_INTR_TX_ABRT) {
198 		src = reg_read(sc, IG4_REG_TX_ABRT_SOURCE);
199 		reg_read(sc, IG4_REG_CLR_TX_ABORT);
200 		/* User-requested abort. Not really a error */
201 		if (src & IG4_ABRTSRC_TRANSFER)
202 			return (IIC_ESTATUS);
203 		/* Master has lost arbitration */
204 		if (src & IG4_ABRTSRC_ARBLOST)
205 			return (IIC_EBUSBSY);
206 		/* Did not receive an acknowledge from the remote slave */
207 		if (src & (IG4_ABRTSRC_TXNOACK_ADDR7 |
208 			   IG4_ABRTSRC_TXNOACK_ADDR10_1 |
209 			   IG4_ABRTSRC_TXNOACK_ADDR10_2 |
210 			   IG4_ABRTSRC_TXNOACK_DATA |
211 			   IG4_ABRTSRC_GENCALL_NOACK))
212 			return (IIC_ENOACK);
213 		/* Programming errors */
214 		if (src & (IG4_ABRTSRC_GENCALL_READ |
215 			   IG4_ABRTSRC_NORESTART_START |
216 			   IG4_ABRTSRC_NORESTART_10))
217 			return (IIC_ENOTSUPP);
218 		/* Other errors */
219 		if (src & IG4_ABRTSRC_ACKED_START)
220 			return (IIC_EBUSERR);
221 	}
222 	/*
223 	 * TX_OVER, RX_OVER and RX_UNDER are caused by wrong RX/TX FIFO depth
224 	 * detection or driver's read/write pipelining errors.
225 	 */
226 	if (val & (IG4_INTR_TX_OVER | IG4_INTR_RX_OVER))
227 		return (IIC_EOVERFLOW);
228 	if (val & IG4_INTR_RX_UNDER)
229 		return (IIC_EUNDERFLOW);
230 
231 	return (IIC_NOERR);
232 }
233 
234 /*
235  * Enable or disable the controller and wait for the controller to acknowledge
236  * the state change.
237  */
238 static int
239 set_controller(ig4iic_softc_t *sc, uint32_t ctl)
240 {
241 	int retry;
242 	int error;
243 	uint32_t v;
244 
245 	/*
246 	 * When the controller is enabled, interrupt on STOP detect
247 	 * or receive character ready and clear pending interrupts.
248 	 */
249 	ig4iic_set_intr_mask(sc, 0);
250 	if (ctl & IG4_I2C_ENABLE)
251 		reg_read(sc, IG4_REG_CLR_INTR);
252 
253 	reg_write(sc, IG4_REG_I2C_EN, ctl);
254 	error = IIC_ETIMEOUT;
255 
256 	for (retry = 100; retry > 0; --retry) {
257 		v = reg_read(sc, IG4_REG_ENABLE_STATUS);
258 		if (((v ^ ctl) & IG4_I2C_ENABLE) == 0) {
259 			error = 0;
260 			break;
261 		}
262 		pause("i2cslv", 1);
263 	}
264 	return (error);
265 }
266 
267 /*
268  * Wait up to 25ms for the requested interrupt using a 25uS polling loop.
269  */
270 static int
271 wait_intr(ig4iic_softc_t *sc, uint32_t intr)
272 {
273 	uint32_t v;
274 	int error;
275 	int txlvl = -1;
276 	u_int count_us = 0;
277 	u_int limit_us = 1000000; /* 1sec */
278 
279 	for (;;) {
280 		/*
281 		 * Check requested status
282 		 */
283 		v = reg_read(sc, IG4_REG_RAW_INTR_STAT);
284 		error = intrstat2iic(sc, v & IG4_INTR_ERR_MASK);
285 		if (error || (v & intr))
286 			break;
287 
288 		/*
289 		 * When waiting for the transmit FIFO to become empty,
290 		 * reset the timeout if we see a change in the transmit
291 		 * FIFO level as progress is being made.
292 		 */
293 		if (intr & (IG4_INTR_TX_EMPTY | IG4_INTR_STOP_DET)) {
294 			v = reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK;
295 			if (txlvl != v) {
296 				txlvl = v;
297 				count_us = 0;
298 			}
299 		}
300 
301 		/*
302 		 * Stop if we've run out of time.
303 		 */
304 		if (count_us >= limit_us) {
305 			error = IIC_ETIMEOUT;
306 			break;
307 		}
308 
309 		/*
310 		 * When polling is not requested let the interrupt do its work.
311 		 */
312 		if (!DO_POLL(sc)) {
313 			mtx_lock_spin(&sc->io_lock);
314 			ig4iic_set_intr_mask(sc, intr | IG4_INTR_ERR_MASK);
315 			msleep_spin(sc, &sc->io_lock, "i2cwait",
316 				  (hz + 99) / 100); /* sleep up to 10ms */
317 			ig4iic_set_intr_mask(sc, 0);
318 			mtx_unlock_spin(&sc->io_lock);
319 			count_us += 10000;
320 		} else {
321 			DELAY(25);
322 			count_us += 25;
323 		}
324 	}
325 
326 	return (error);
327 }
328 
329 /*
330  * Set the slave address.  The controller must be disabled when
331  * changing the address.
332  *
333  * This operation does not issue anything to the I2C bus but sets
334  * the target address for when the controller later issues a START.
335  */
336 static void
337 set_slave_addr(ig4iic_softc_t *sc, uint8_t slave)
338 {
339 	uint32_t tar;
340 	uint32_t ctl;
341 	bool use_10bit;
342 
343 	use_10bit = false;
344 	if (sc->slave_valid && sc->last_slave == slave &&
345 	    sc->use_10bit == use_10bit) {
346 		return;
347 	}
348 	sc->use_10bit = use_10bit;
349 
350 	/*
351 	 * Wait for TXFIFO to drain before disabling the controller.
352 	 */
353 	wait_intr(sc, IG4_INTR_TX_EMPTY);
354 
355 	set_controller(sc, 0);
356 	ctl = reg_read(sc, IG4_REG_CTL);
357 	ctl &= ~IG4_CTL_10BIT;
358 	ctl |= IG4_CTL_RESTARTEN;
359 
360 	tar = slave;
361 	if (sc->use_10bit) {
362 		tar |= IG4_TAR_10BIT;
363 		ctl |= IG4_CTL_10BIT;
364 	}
365 	reg_write(sc, IG4_REG_CTL, ctl);
366 	reg_write(sc, IG4_REG_TAR_ADD, tar);
367 	set_controller(sc, IG4_I2C_ENABLE);
368 	sc->slave_valid = true;
369 	sc->last_slave = slave;
370 }
371 
372 /*
373  *				IICBUS API FUNCTIONS
374  */
375 static int
376 ig4iic_xfer_start(ig4iic_softc_t *sc, uint16_t slave, bool repeated_start)
377 {
378 	set_slave_addr(sc, slave >> 1);
379 
380 	if (!repeated_start) {
381 		/*
382 		 * Clear any previous TX/RX FIFOs overflow/underflow bits
383 		 * and I2C bus STOP condition.
384 		 */
385 		reg_read(sc, IG4_REG_CLR_INTR);
386 	}
387 
388 	return (0);
389 }
390 
391 static bool
392 ig4iic_xfer_is_started(ig4iic_softc_t *sc)
393 {
394 	/*
395 	 * It requires that no IG4_REG_CLR_INTR or IG4_REG_CLR_START/STOP_DET
396 	 * register reads is issued after START condition.
397 	 */
398 	return ((reg_read(sc, IG4_REG_RAW_INTR_STAT) &
399 	    (IG4_INTR_START_DET | IG4_INTR_STOP_DET)) == IG4_INTR_START_DET);
400 }
401 
402 static int
403 ig4iic_xfer_abort(ig4iic_softc_t *sc)
404 {
405 	int error;
406 
407 	/* Request send of STOP condition and flush of TX FIFO */
408 	set_controller(sc, IG4_I2C_ABORT | IG4_I2C_ENABLE);
409 	/*
410 	 * Wait for the TX_ABRT interrupt with ABRTSRC_TRANSFER
411 	 * bit set in TX_ABRT_SOURCE register.
412 	 */
413 	error = wait_intr(sc, IG4_INTR_STOP_DET);
414 	set_controller(sc, IG4_I2C_ENABLE);
415 
416 	return (error == IIC_ESTATUS ? 0 : error);
417 }
418 
419 /*
420  * Amount of unread data before next burst to get better I2C bus utilization.
421  * 2 bytes is enough in FAST mode. 8 bytes is better in FAST+ and HIGH modes.
422  * Intel-recommended value is 16 for DMA transfers with 64-byte depth FIFOs.
423  */
424 #define	IG4_FIFO_LOWAT	2
425 
426 static int
427 ig4iic_read(ig4iic_softc_t *sc, uint8_t *buf, uint16_t len,
428     bool repeated_start, bool stop)
429 {
430 	uint32_t cmd;
431 	int requested = 0;
432 	int received = 0;
433 	int burst, target, lowat = 0;
434 	int error;
435 
436 	if (len == 0)
437 		return (0);
438 
439 	while (received < len) {
440 		burst = sc->cfg.txfifo_depth -
441 		    (reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
442 		if (burst <= 0) {
443 			error = wait_intr(sc, IG4_INTR_TX_EMPTY);
444 			if (error)
445 				break;
446 			burst = sc->cfg.txfifo_depth;
447 		}
448 		/* Ensure we have enough free space in RXFIFO */
449 		burst = MIN(burst, sc->cfg.rxfifo_depth - lowat);
450 		target = MIN(requested + burst, (int)len);
451 		while (requested < target) {
452 			cmd = IG4_DATA_COMMAND_RD;
453 			if (repeated_start && requested == 0)
454 				cmd |= IG4_DATA_RESTART;
455 			if (stop && requested == len - 1)
456 				cmd |= IG4_DATA_STOP;
457 			reg_write(sc, IG4_REG_DATA_CMD, cmd);
458 			requested++;
459 		}
460 		/* Leave some data queued to maintain the hardware pipeline */
461 		lowat = 0;
462 		if (requested != len && requested - received > IG4_FIFO_LOWAT)
463 			lowat = IG4_FIFO_LOWAT;
464 		/* After TXFLR fills up, clear it by reading available data */
465 		while (received < requested - lowat) {
466 			burst = MIN((int)len - received,
467 			    reg_read(sc, IG4_REG_RXFLR) & IG4_FIFOLVL_MASK);
468 			if (burst > 0) {
469 				while (burst--)
470 					buf[received++] = 0xFF &
471 					    reg_read(sc, IG4_REG_DATA_CMD);
472 			} else {
473 				error = wait_intr(sc, IG4_INTR_RX_FULL);
474 				if (error)
475 					goto out;
476 			}
477 		}
478 	}
479 out:
480 	return (error);
481 }
482 
483 static int
484 ig4iic_write(ig4iic_softc_t *sc, uint8_t *buf, uint16_t len,
485     bool repeated_start, bool stop)
486 {
487 	uint32_t cmd;
488 	int sent = 0;
489 	int burst, target;
490 	int error;
491 	bool lowat_set = false;
492 
493 	if (len == 0)
494 		return (0);
495 
496 	while (sent < len) {
497 		burst = sc->cfg.txfifo_depth -
498 		    (reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
499 		target = MIN(sent + burst, (int)len);
500 		/* Leave some data queued to maintain the hardware pipeline */
501 		if (!lowat_set && target != len) {
502 			lowat_set = true;
503 			reg_write(sc, IG4_REG_TX_TL, IG4_FIFO_LOWAT);
504 		}
505 		while(sent < target) {
506 			cmd = buf[sent];
507 			if (repeated_start && sent == 0)
508 				cmd |= IG4_DATA_RESTART;
509 			if (stop && sent == len - 1)
510 				cmd |= IG4_DATA_STOP;
511 			reg_write(sc, IG4_REG_DATA_CMD, cmd);
512 			sent++;
513 		}
514 		if (sent < len) {
515 			error = wait_intr(sc, IG4_INTR_TX_EMPTY);
516 			if (error)
517 				break;
518 		}
519 	}
520 	if (lowat_set)
521 		reg_write(sc, IG4_REG_TX_TL, 0);
522 
523 	return (error);
524 }
525 
526 int
527 ig4iic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
528 {
529 	ig4iic_softc_t *sc = device_get_softc(dev);
530 	const char *reason = NULL;
531 	uint32_t i;
532 	int error;
533 	int unit;
534 	bool rpstart;
535 	bool stop;
536 	bool allocated;
537 
538 	/*
539 	 * The hardware interface imposes limits on allowed I2C messages.
540 	 * It is not possible to explicitly send a start or stop.
541 	 * They are automatically sent (or not sent, depending on the
542 	 * configuration) when a data byte is transferred.
543 	 * For this reason it's impossible to send a message with no data
544 	 * at all (like an SMBus quick message).
545 	 * The start condition is automatically generated after the stop
546 	 * condition, so it's impossible to not have a start after a stop.
547 	 * The repeated start condition is automatically sent if a change
548 	 * of the transfer direction happens, so it's impossible to have
549 	 * a change of direction without a (repeated) start.
550 	 * The repeated start can be forced even without the change of
551 	 * direction.
552 	 * Changing the target slave address requires resetting the hardware
553 	 * state, so it's impossible to do that without the stop followed
554 	 * by the start.
555 	 */
556 	for (i = 0; i < nmsgs; i++) {
557 #if 0
558 		if (i == 0 && (msgs[i].flags & IIC_M_NOSTART) != 0) {
559 			reason = "first message without start";
560 			break;
561 		}
562 		if (i == nmsgs - 1 && (msgs[i].flags & IIC_M_NOSTOP) != 0) {
563 			reason = "last message without stop";
564 			break;
565 		}
566 #endif
567 		if (msgs[i].len == 0) {
568 			reason = "message with no data";
569 			break;
570 		}
571 		if (i > 0) {
572 			if ((msgs[i].flags & IIC_M_NOSTART) != 0 &&
573 			    (msgs[i - 1].flags & IIC_M_NOSTOP) == 0) {
574 				reason = "stop not followed by start";
575 				break;
576 			}
577 			if ((msgs[i - 1].flags & IIC_M_NOSTOP) != 0 &&
578 			    msgs[i].slave != msgs[i - 1].slave) {
579 				reason = "change of slave without stop";
580 				break;
581 			}
582 			if ((msgs[i].flags & IIC_M_NOSTART) != 0 &&
583 			    (msgs[i].flags & IIC_M_RD) !=
584 			    (msgs[i - 1].flags & IIC_M_RD)) {
585 				reason = "change of direction without repeated"
586 				    " start";
587 				break;
588 			}
589 		}
590 	}
591 	if (reason != NULL) {
592 		if (bootverbose)
593 			device_printf(dev, "%s\n", reason);
594 		return (IIC_ENOTSUPP);
595 	}
596 
597 	/* Check if device is already allocated with iicbus_request_bus() */
598 	allocated = sx_xlocked(&sc->call_lock) != 0;
599 	if (!allocated)
600 		sx_xlock(&sc->call_lock);
601 
602 	/* Debugging - dump registers. */
603 	if (ig4_dump) {
604 		unit = device_get_unit(dev);
605 		if (ig4_dump & (1 << unit)) {
606 			ig4_dump &= ~(1 << unit);
607 			ig4iic_dump(sc);
608 		}
609 	}
610 
611 	/*
612 	 * Clear any previous abort condition that may have been holding
613 	 * the txfifo in reset.
614 	 */
615 	reg_read(sc, IG4_REG_CLR_TX_ABORT);
616 
617 	rpstart = false;
618 	error = 0;
619 	for (i = 0; i < nmsgs; i++) {
620 		if ((msgs[i].flags & IIC_M_NOSTART) == 0) {
621 			error = ig4iic_xfer_start(sc, msgs[i].slave, rpstart);
622 		} else {
623 			if (!sc->slave_valid ||
624 			    (msgs[i].slave >> 1) != sc->last_slave) {
625 				device_printf(dev, "start condition suppressed"
626 				    "but slave address is not set up");
627 				error = EINVAL;
628 				break;
629 			}
630 			rpstart = false;
631 		}
632 		if (error != 0)
633 			break;
634 
635 		stop = (msgs[i].flags & IIC_M_NOSTOP) == 0;
636 		if (msgs[i].flags & IIC_M_RD)
637 			error = ig4iic_read(sc, msgs[i].buf, msgs[i].len,
638 			    rpstart, stop);
639 		else
640 			error = ig4iic_write(sc, msgs[i].buf, msgs[i].len,
641 			    rpstart, stop);
642 
643 		/* Wait for error or stop condition occurred on the I2C bus */
644 		if (stop && error == 0) {
645 			error = wait_intr(sc, IG4_INTR_STOP_DET);
646 			if (error == 0)
647 				reg_read(sc, IG4_REG_CLR_INTR);
648 		}
649 
650 		if (error != 0) {
651 			/*
652 			 * Send STOP condition if it's not done yet and flush
653 			 * both FIFOs. Do a controller soft reset if transfer
654 			 * abort is failed.
655 			 */
656 			if (ig4iic_xfer_is_started(sc) &&
657 			    ig4iic_xfer_abort(sc) != 0) {
658 				device_printf(sc->dev, "Failed to abort "
659 				    "transfer. Do the controller reset.\n");
660 				ig4iic_set_config(sc, true);
661 			} else {
662 				while (reg_read(sc, IG4_REG_I2C_STA) &
663 				    IG4_STATUS_RX_NOTEMPTY)
664 					reg_read(sc, IG4_REG_DATA_CMD);
665 				reg_read(sc, IG4_REG_TX_ABRT_SOURCE);
666 				reg_read(sc, IG4_REG_CLR_INTR);
667 			}
668 			break;
669 		}
670 
671 		rpstart = !stop;
672 	}
673 
674 	if (!allocated)
675 		sx_unlock(&sc->call_lock);
676 	return (error);
677 }
678 
679 int
680 ig4iic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
681 {
682 	ig4iic_softc_t *sc = device_get_softc(dev);
683 	bool allocated;
684 
685 	allocated = sx_xlocked(&sc->call_lock) != 0;
686 	if (!allocated)
687 		sx_xlock(&sc->call_lock);
688 
689 	/* TODO handle speed configuration? */
690 	if (oldaddr != NULL)
691 		*oldaddr = sc->last_slave << 1;
692 	set_slave_addr(sc, addr >> 1);
693 	if (addr == IIC_UNKNOWN)
694 		sc->slave_valid = false;
695 
696 	if (!allocated)
697 		sx_unlock(&sc->call_lock);
698 	return (0);
699 }
700 
701 int
702 ig4iic_callback(device_t dev, int index, caddr_t data)
703 {
704 	ig4iic_softc_t *sc = device_get_softc(dev);
705 	int error = 0;
706 	int how;
707 
708 	switch (index) {
709 	case IIC_REQUEST_BUS:
710 		/* force polling if ig4iic is requested with IIC_DONTWAIT */
711 		how = *(int *)data;
712 		if ((how & IIC_WAIT) == 0) {
713 			if (sx_try_xlock(&sc->call_lock) == 0)
714 				error = IIC_EBUSBSY;
715 			else
716 				sc->poll = true;
717 		} else
718 			sx_xlock(&sc->call_lock);
719 		break;
720 
721 	case IIC_RELEASE_BUS:
722 		sc->poll = false;
723 		sx_unlock(&sc->call_lock);
724 		break;
725 
726 	default:
727 		error = errno2iic(EINVAL);
728 	}
729 
730 	return (error);
731 }
732 
733 /*
734  * Clock register values can be calculated with following rough equations:
735  * SCL_HCNT = ceil(IC clock rate * tHIGH)
736  * SCL_LCNT = ceil(IC clock rate * tLOW)
737  * SDA_HOLD = ceil(IC clock rate * SDA hold time)
738  * Precise equations take signal's falling, rising and spike suppression
739  * times in to account. They can be found in Synopsys or Intel documentation.
740  *
741  * Here we snarf formulas and defaults from Linux driver to be able to use
742  * timing values provided by Intel LPSS driver "as is".
743  */
744 static int
745 ig4iic_clk_params(const struct ig4_hw *hw, int speed,
746     uint16_t *scl_hcnt, uint16_t *scl_lcnt, uint16_t *sda_hold)
747 {
748 	uint32_t thigh, tlow, tf_max;	/* nsec */
749 	uint32_t sda_fall_time;		/* nsec */
750         uint32_t scl_fall_time;		/* nsec */
751 
752 	switch (speed) {
753 	case IG4_CTL_SPEED_STD:
754 		thigh = IG4_SPEED_STD_THIGH;
755 		tlow = IG4_SPEED_STD_TLOW;
756 		tf_max = IG4_SPEED_STD_TF_MAX;
757 		break;
758 
759 	case IG4_CTL_SPEED_FAST:
760 		thigh = IG4_SPEED_FAST_THIGH;
761 		tlow = IG4_SPEED_FAST_TLOW;
762 		tf_max = IG4_SPEED_FAST_TF_MAX;
763 		break;
764 
765 	default:
766 		return (EINVAL);
767 	}
768 
769 	/* Use slowest falling time defaults to be on the safe side */
770 	sda_fall_time = hw->sda_fall_time == 0 ? tf_max : hw->sda_fall_time;
771 	*scl_hcnt = (uint16_t)
772 	    ((hw->ic_clock_rate * (thigh + sda_fall_time) + 500) / 1000 - 3);
773 
774 	scl_fall_time = hw->scl_fall_time == 0 ? tf_max : hw->scl_fall_time;
775 	*scl_lcnt = (uint16_t)
776 	    ((hw->ic_clock_rate * (tlow + scl_fall_time) + 500) / 1000 - 1);
777 
778 	/*
779 	 * There is no "known good" default value for tHD;DAT so keep SDA_HOLD
780 	 * intact if sda_hold_time value is not provided.
781 	 */
782 	if (hw->sda_hold_time != 0)
783 		*sda_hold = (uint16_t)
784 		    ((hw->ic_clock_rate * hw->sda_hold_time + 500) / 1000);
785 
786 	return (0);
787 }
788 
789 #ifdef DEV_ACPI
790 static ACPI_STATUS
791 ig4iic_acpi_params(ACPI_HANDLE handle, char *method,
792     uint16_t *scl_hcnt, uint16_t *scl_lcnt, uint16_t *sda_hold)
793 {
794 	ACPI_BUFFER buf;
795 	ACPI_OBJECT *obj, *elems;
796 	ACPI_STATUS status;
797 
798 	buf.Pointer = NULL;
799 	buf.Length = ACPI_ALLOCATE_BUFFER;
800 
801 	status = AcpiEvaluateObject(handle, method, NULL, &buf);
802 	if (ACPI_FAILURE(status))
803 		return (status);
804 
805 	status = AE_TYPE;
806 	obj = (ACPI_OBJECT *)buf.Pointer;
807 	if (obj->Type == ACPI_TYPE_PACKAGE && obj->Package.Count == 3) {
808 		elems = obj->Package.Elements;
809 		*scl_hcnt = elems[0].Integer.Value & IG4_SCL_CLOCK_MASK;
810 		*scl_lcnt = elems[1].Integer.Value & IG4_SCL_CLOCK_MASK;
811 		*sda_hold = elems[2].Integer.Value & IG4_SDA_TX_HOLD_MASK;
812 		status = AE_OK;
813 	}
814 
815 	AcpiOsFree(obj);
816 
817 	return (status);
818 }
819 #endif /* DEV_ACPI */
820 
821 static void
822 ig4iic_get_config(ig4iic_softc_t *sc)
823 {
824 	const struct ig4_hw *hw;
825 	uint32_t v;
826 #ifdef DEV_ACPI
827 	ACPI_HANDLE handle;
828 #endif
829 	/* Fetch default hardware config from controller */
830 	sc->cfg.version = reg_read(sc, IG4_REG_COMP_VER);
831 	sc->cfg.bus_speed = reg_read(sc, IG4_REG_CTL) & IG4_CTL_SPEED_MASK;
832 	sc->cfg.ss_scl_hcnt =
833 	    reg_read(sc, IG4_REG_SS_SCL_HCNT) & IG4_SCL_CLOCK_MASK;
834 	sc->cfg.ss_scl_lcnt =
835 	    reg_read(sc, IG4_REG_SS_SCL_LCNT) & IG4_SCL_CLOCK_MASK;
836 	sc->cfg.fs_scl_hcnt =
837 	    reg_read(sc, IG4_REG_FS_SCL_HCNT) & IG4_SCL_CLOCK_MASK;
838 	sc->cfg.fs_scl_lcnt =
839 	    reg_read(sc, IG4_REG_FS_SCL_LCNT) & IG4_SCL_CLOCK_MASK;
840 	sc->cfg.ss_sda_hold = sc->cfg.fs_sda_hold =
841 	    reg_read(sc, IG4_REG_SDA_HOLD) & IG4_SDA_TX_HOLD_MASK;
842 
843 	if (sc->cfg.bus_speed != IG4_CTL_SPEED_STD)
844 		sc->cfg.bus_speed = IG4_CTL_SPEED_FAST;
845 
846 	/* REG_COMP_PARAM1 is not documented in latest Intel specs */
847 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
848 		v = reg_read(sc, IG4_REG_COMP_PARAM1);
849 		if (IG4_PARAM1_TXFIFO_DEPTH(v) != 0)
850 			sc->cfg.txfifo_depth = IG4_PARAM1_TXFIFO_DEPTH(v);
851 		if (IG4_PARAM1_RXFIFO_DEPTH(v) != 0)
852 			sc->cfg.rxfifo_depth = IG4_PARAM1_RXFIFO_DEPTH(v);
853 	} else {
854 		/*
855 		 * Hardware does not allow FIFO Threshold Levels value to be
856 		 * set larger than the depth of the buffer. If an attempt is
857 		 * made to do that, the actual value set will be the maximum
858 		 * depth of the buffer.
859 		 */
860 		v = reg_read(sc, IG4_REG_TX_TL);
861 		reg_write(sc, IG4_REG_TX_TL, v | IG4_FIFO_MASK);
862 		sc->cfg.txfifo_depth =
863 		    (reg_read(sc, IG4_REG_TX_TL) & IG4_FIFO_MASK) + 1;
864 		reg_write(sc, IG4_REG_TX_TL, v);
865 		v = reg_read(sc, IG4_REG_RX_TL);
866 		reg_write(sc, IG4_REG_RX_TL, v | IG4_FIFO_MASK);
867 		sc->cfg.rxfifo_depth =
868 		    (reg_read(sc, IG4_REG_RX_TL) & IG4_FIFO_MASK) + 1;
869 		reg_write(sc, IG4_REG_RX_TL, v);
870 	}
871 
872 	/* Override hardware config with IC_clock-based counter values */
873 	if (ig4_timings < 2 && sc->version < nitems(ig4iic_hw)) {
874 		hw = &ig4iic_hw[sc->version];
875 		sc->cfg.bus_speed = IG4_CTL_SPEED_FAST;
876 		ig4iic_clk_params(hw, IG4_CTL_SPEED_STD, &sc->cfg.ss_scl_hcnt,
877 		    &sc->cfg.ss_scl_lcnt, &sc->cfg.ss_sda_hold);
878 		ig4iic_clk_params(hw, IG4_CTL_SPEED_FAST, &sc->cfg.fs_scl_hcnt,
879 		    &sc->cfg.fs_scl_lcnt, &sc->cfg.fs_sda_hold);
880 		if (hw->txfifo_depth != 0)
881 			sc->cfg.txfifo_depth = hw->txfifo_depth;
882 		if (hw->rxfifo_depth != 0)
883 			sc->cfg.rxfifo_depth = hw->rxfifo_depth;
884 	} else if (ig4_timings == 2) {
885 		/*
886 		 * Timings of original ig4 driver:
887 		 * Program based on a 25000 Hz clock.  This is a bit of a
888 		 * hack (obviously).  The defaults are 400 and 470 for standard
889 		 * and 60 and 130 for fast.  The defaults for standard fail
890 		 * utterly (presumably cause an abort) because the clock time
891 		 * is ~18.8ms by default.  This brings it down to ~4ms.
892 		 */
893 		sc->cfg.bus_speed = IG4_CTL_SPEED_STD;
894 		sc->cfg.ss_scl_hcnt = sc->cfg.fs_scl_hcnt = 100;
895 		sc->cfg.ss_scl_lcnt = sc->cfg.fs_scl_lcnt = 125;
896 		if (sc->version == IG4_SKYLAKE)
897 			sc->cfg.ss_sda_hold = sc->cfg.fs_sda_hold = 28;
898 	}
899 
900 #ifdef DEV_ACPI
901 	/* Evaluate SSCN and FMCN ACPI methods to fetch timings */
902 	if (ig4_timings == 0 && (handle = acpi_get_handle(sc->dev)) != NULL) {
903 		ig4iic_acpi_params(handle, "SSCN", &sc->cfg.ss_scl_hcnt,
904 		    &sc->cfg.ss_scl_lcnt, &sc->cfg.ss_sda_hold);
905 		ig4iic_acpi_params(handle, "FMCN", &sc->cfg.fs_scl_hcnt,
906 		    &sc->cfg.fs_scl_lcnt, &sc->cfg.fs_sda_hold);
907 	}
908 #endif
909 
910 	if (bootverbose) {
911 		device_printf(sc->dev, "Controller parameters:\n");
912 		printf("  Speed: %s\n",
913 		    sc->cfg.bus_speed == IG4_CTL_SPEED_STD ? "Std" : "Fast");
914 		printf("  Regs:  HCNT  :LCNT  :SDAHLD\n");
915 		printf("  Std:   0x%04hx:0x%04hx:0x%04hx\n",
916 		    sc->cfg.ss_scl_hcnt, sc->cfg.ss_scl_lcnt,
917 		    sc->cfg.ss_sda_hold);
918 		printf("  Fast:  0x%04hx:0x%04hx:0x%04hx\n",
919 		    sc->cfg.fs_scl_hcnt, sc->cfg.fs_scl_lcnt,
920 		    sc->cfg.fs_sda_hold);
921 		printf("  FIFO:  RX:0x%04x: TX:0x%04x\n",
922 		    sc->cfg.rxfifo_depth, sc->cfg.txfifo_depth);
923 	}
924 }
925 
926 static int
927 ig4iic_set_config(ig4iic_softc_t *sc, bool reset)
928 {
929 	uint32_t v;
930 
931 	v = reg_read(sc, IG4_REG_DEVIDLE_CTRL);
932 	if (IG4_HAS_ADDREGS(sc->version) && (v & IG4_RESTORE_REQUIRED)) {
933 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, IG4_DEVICE_IDLE | IG4_RESTORE_REQUIRED);
934 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, 0);
935 		pause("i2crst", 1);
936 		reset = true;
937 	}
938 
939 	if ((sc->version == IG4_HASWELL || sc->version == IG4_ATOM) && reset) {
940 		reg_write(sc, IG4_REG_RESETS_HSW, IG4_RESETS_ASSERT_HSW);
941 		reg_write(sc, IG4_REG_RESETS_HSW, IG4_RESETS_DEASSERT_HSW);
942 	} else if (IG4_HAS_ADDREGS(sc->version) && reset) {
943 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_ASSERT_SKL);
944 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_DEASSERT_SKL);
945 	}
946 
947 	if (sc->version == IG4_ATOM)
948 		v = reg_read(sc, IG4_REG_COMP_TYPE);
949 
950 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
951 		v = reg_read(sc, IG4_REG_COMP_PARAM1);
952 		v = reg_read(sc, IG4_REG_GENERAL);
953 		/*
954 		 * The content of IG4_REG_GENERAL is different for each
955 		 * controller version.
956 		 */
957 		if (sc->version == IG4_HASWELL &&
958 		    (v & IG4_GENERAL_SWMODE) == 0) {
959 			v |= IG4_GENERAL_SWMODE;
960 			reg_write(sc, IG4_REG_GENERAL, v);
961 			v = reg_read(sc, IG4_REG_GENERAL);
962 		}
963 	}
964 
965 	if (sc->version == IG4_HASWELL) {
966 		v = reg_read(sc, IG4_REG_SW_LTR_VALUE);
967 		v = reg_read(sc, IG4_REG_AUTO_LTR_VALUE);
968 	} else if (IG4_HAS_ADDREGS(sc->version)) {
969 		v = reg_read(sc, IG4_REG_ACTIVE_LTR_VALUE);
970 		v = reg_read(sc, IG4_REG_IDLE_LTR_VALUE);
971 	}
972 
973 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
974 		v = reg_read(sc, IG4_REG_COMP_VER);
975 		if (v < IG4_COMP_MIN_VER)
976 			return(ENXIO);
977 	}
978 
979 	if (set_controller(sc, 0)) {
980 		device_printf(sc->dev, "controller error during attach-1\n");
981 		return (ENXIO);
982 	}
983 
984 	reg_read(sc, IG4_REG_CLR_INTR);
985 	reg_write(sc, IG4_REG_INTR_MASK, 0);
986 	sc->intr_mask = 0;
987 
988 	reg_write(sc, IG4_REG_SS_SCL_HCNT, sc->cfg.ss_scl_hcnt);
989 	reg_write(sc, IG4_REG_SS_SCL_LCNT, sc->cfg.ss_scl_lcnt);
990 	reg_write(sc, IG4_REG_FS_SCL_HCNT, sc->cfg.fs_scl_hcnt);
991 	reg_write(sc, IG4_REG_FS_SCL_LCNT, sc->cfg.fs_scl_lcnt);
992 	reg_write(sc, IG4_REG_SDA_HOLD,
993 	    (sc->cfg.bus_speed  & IG4_CTL_SPEED_MASK) == IG4_CTL_SPEED_STD ?
994 	      sc->cfg.ss_sda_hold : sc->cfg.fs_sda_hold);
995 
996 	/*
997 	 * Use a threshold of 1 so we get interrupted on each character,
998 	 * allowing us to use mtx_sleep() in our poll code.  Not perfect
999 	 * but this is better than using DELAY() for receiving data.
1000 	 *
1001 	 * See ig4_var.h for details on interrupt handler synchronization.
1002 	 */
1003 	reg_write(sc, IG4_REG_RX_TL, 0);
1004 	reg_write(sc, IG4_REG_TX_TL, 0);
1005 
1006 	reg_write(sc, IG4_REG_CTL,
1007 		  IG4_CTL_MASTER |
1008 		  IG4_CTL_SLAVE_DISABLE |
1009 		  IG4_CTL_RESTARTEN |
1010 		  (sc->cfg.bus_speed & IG4_CTL_SPEED_MASK));
1011 
1012 	/* Force setting of the target address on the next transfer */
1013 	sc->slave_valid = false;
1014 
1015 	return (0);
1016 }
1017 
1018 /*
1019  * Called from ig4iic_pci_attach/detach()
1020  */
1021 int
1022 ig4iic_attach(ig4iic_softc_t *sc)
1023 {
1024 	int error;
1025 
1026 	mtx_init(&sc->io_lock, "IG4 I/O lock", NULL, MTX_SPIN);
1027 	sx_init(&sc->call_lock, "IG4 call lock");
1028 
1029 	ig4iic_get_config(sc);
1030 
1031 	error = ig4iic_set_config(sc, IG4_HAS_ADDREGS(sc->version));
1032 	if (error)
1033 		goto done;
1034 
1035 	sc->iicbus = device_add_child(sc->dev, "iicbus", -1);
1036 	if (sc->iicbus == NULL) {
1037 		device_printf(sc->dev, "iicbus driver not found\n");
1038 		error = ENXIO;
1039 		goto done;
1040 	}
1041 
1042 	if (set_controller(sc, IG4_I2C_ENABLE)) {
1043 		device_printf(sc->dev, "controller error during attach-2\n");
1044 		error = ENXIO;
1045 		goto done;
1046 	}
1047 	if (set_controller(sc, 0)) {
1048 		device_printf(sc->dev, "controller error during attach-3\n");
1049 		error = ENXIO;
1050 		goto done;
1051 	}
1052 	error = bus_setup_intr(sc->dev, sc->intr_res, INTR_TYPE_MISC | INTR_MPSAFE,
1053 			       ig4iic_intr, NULL, sc, &sc->intr_handle);
1054 	if (error) {
1055 		device_printf(sc->dev,
1056 			      "Unable to setup irq: error %d\n", error);
1057 	}
1058 
1059 	error = bus_generic_attach(sc->dev);
1060 	if (error) {
1061 		device_printf(sc->dev,
1062 			      "failed to attach child: error %d\n", error);
1063 	}
1064 
1065 done:
1066 	return (error);
1067 }
1068 
1069 int
1070 ig4iic_detach(ig4iic_softc_t *sc)
1071 {
1072 	int error;
1073 
1074 	if (device_is_attached(sc->dev)) {
1075 		error = bus_generic_detach(sc->dev);
1076 		if (error)
1077 			return (error);
1078 	}
1079 	if (sc->iicbus)
1080 		device_delete_child(sc->dev, sc->iicbus);
1081 	if (sc->intr_handle)
1082 		bus_teardown_intr(sc->dev, sc->intr_res, sc->intr_handle);
1083 
1084 	sx_xlock(&sc->call_lock);
1085 
1086 	sc->iicbus = NULL;
1087 	sc->intr_handle = NULL;
1088 	reg_write(sc, IG4_REG_INTR_MASK, 0);
1089 	set_controller(sc, 0);
1090 
1091 	sx_xunlock(&sc->call_lock);
1092 
1093 	mtx_destroy(&sc->io_lock);
1094 	sx_destroy(&sc->call_lock);
1095 
1096 	return (0);
1097 }
1098 
1099 int
1100 ig4iic_suspend(ig4iic_softc_t *sc)
1101 {
1102 	int error;
1103 
1104 	/* suspend all children */
1105 	error = bus_generic_suspend(sc->dev);
1106 
1107 	sx_xlock(&sc->call_lock);
1108 	set_controller(sc, 0);
1109 	if (IG4_HAS_ADDREGS(sc->version)) {
1110 		/*
1111 		 * Place the device in the idle state, just to be safe
1112 		 */
1113 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, IG4_DEVICE_IDLE);
1114 		/*
1115 		 * Controller can become dysfunctional if I2C lines are pulled
1116 		 * down when suspend procedure turns off power to I2C device.
1117 		 * Place device in the reset state to avoid this.
1118 		 */
1119 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_ASSERT_SKL);
1120 	}
1121 	sx_xunlock(&sc->call_lock);
1122 
1123 	return (error);
1124 }
1125 
1126 int ig4iic_resume(ig4iic_softc_t *sc)
1127 {
1128 	int error;
1129 
1130 	sx_xlock(&sc->call_lock);
1131 	if (ig4iic_set_config(sc, IG4_HAS_ADDREGS(sc->version)))
1132 		device_printf(sc->dev, "controller error during resume\n");
1133 	sx_xunlock(&sc->call_lock);
1134 
1135 	error = bus_generic_resume(sc->dev);
1136 
1137 	return (error);
1138 }
1139 
1140 /*
1141  * Interrupt Operation, see ig4_var.h for locking semantics.
1142  */
1143 static int
1144 ig4iic_intr(void *cookie)
1145 {
1146 	ig4iic_softc_t *sc = cookie;
1147 	int retval = FILTER_STRAY;
1148 
1149 	mtx_lock_spin(&sc->io_lock);
1150 	/* Ignore stray interrupts */
1151 	if (sc->intr_mask != 0 && reg_read(sc, IG4_REG_INTR_STAT) != 0) {
1152 		/* Interrupt bits are cleared in wait_intr() loop */
1153 		ig4iic_set_intr_mask(sc, 0);
1154 		wakeup(sc);
1155 		retval = FILTER_HANDLED;
1156 	}
1157 	mtx_unlock_spin(&sc->io_lock);
1158 
1159 	return (retval);
1160 }
1161 
1162 #define REGDUMP(sc, reg)	\
1163 	device_printf(sc->dev, "  %-23s %08x\n", #reg, reg_read(sc, reg))
1164 
1165 static void
1166 ig4iic_dump(ig4iic_softc_t *sc)
1167 {
1168 	device_printf(sc->dev, "ig4iic register dump:\n");
1169 	REGDUMP(sc, IG4_REG_CTL);
1170 	REGDUMP(sc, IG4_REG_TAR_ADD);
1171 	REGDUMP(sc, IG4_REG_SS_SCL_HCNT);
1172 	REGDUMP(sc, IG4_REG_SS_SCL_LCNT);
1173 	REGDUMP(sc, IG4_REG_FS_SCL_HCNT);
1174 	REGDUMP(sc, IG4_REG_FS_SCL_LCNT);
1175 	REGDUMP(sc, IG4_REG_INTR_STAT);
1176 	REGDUMP(sc, IG4_REG_INTR_MASK);
1177 	REGDUMP(sc, IG4_REG_RAW_INTR_STAT);
1178 	REGDUMP(sc, IG4_REG_RX_TL);
1179 	REGDUMP(sc, IG4_REG_TX_TL);
1180 	REGDUMP(sc, IG4_REG_I2C_EN);
1181 	REGDUMP(sc, IG4_REG_I2C_STA);
1182 	REGDUMP(sc, IG4_REG_TXFLR);
1183 	REGDUMP(sc, IG4_REG_RXFLR);
1184 	REGDUMP(sc, IG4_REG_SDA_HOLD);
1185 	REGDUMP(sc, IG4_REG_TX_ABRT_SOURCE);
1186 	REGDUMP(sc, IG4_REG_SLV_DATA_NACK);
1187 	REGDUMP(sc, IG4_REG_DMA_CTRL);
1188 	REGDUMP(sc, IG4_REG_DMA_TDLR);
1189 	REGDUMP(sc, IG4_REG_DMA_RDLR);
1190 	REGDUMP(sc, IG4_REG_SDA_SETUP);
1191 	REGDUMP(sc, IG4_REG_ENABLE_STATUS);
1192 	REGDUMP(sc, IG4_REG_COMP_PARAM1);
1193 	REGDUMP(sc, IG4_REG_COMP_VER);
1194 	if (sc->version == IG4_ATOM) {
1195 		REGDUMP(sc, IG4_REG_COMP_TYPE);
1196 		REGDUMP(sc, IG4_REG_CLK_PARMS);
1197 	}
1198 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
1199 		REGDUMP(sc, IG4_REG_RESETS_HSW);
1200 		REGDUMP(sc, IG4_REG_GENERAL);
1201 	} else if (sc->version == IG4_SKYLAKE) {
1202 		REGDUMP(sc, IG4_REG_RESETS_SKL);
1203 	}
1204 	if (sc->version == IG4_HASWELL) {
1205 		REGDUMP(sc, IG4_REG_SW_LTR_VALUE);
1206 		REGDUMP(sc, IG4_REG_AUTO_LTR_VALUE);
1207 	} else if (IG4_HAS_ADDREGS(sc->version)) {
1208 		REGDUMP(sc, IG4_REG_ACTIVE_LTR_VALUE);
1209 		REGDUMP(sc, IG4_REG_IDLE_LTR_VALUE);
1210 	}
1211 }
1212 #undef REGDUMP
1213 
1214 DRIVER_MODULE(iicbus, ig4iic, iicbus_driver, NULL, NULL);
1215 #ifdef DEV_ACPI
1216 DRIVER_MODULE(acpi_iicbus, ig4iic, acpi_iicbus_driver, NULL, NULL);
1217 #endif
1218 MODULE_DEPEND(ig4iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
1219 MODULE_VERSION(ig4iic, 1);
1220