xref: /freebsd/sys/dev/ichiic/ig4_iic.c (revision 562894f0dc310f658284863ff329906e7737a0a0)
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 };
123 
124 static int ig4iic_set_config(ig4iic_softc_t *sc, bool reset);
125 static driver_filter_t ig4iic_intr;
126 static void ig4iic_dump(ig4iic_softc_t *sc);
127 
128 static int ig4_dump;
129 SYSCTL_INT(_debug, OID_AUTO, ig4_dump, CTLFLAG_RW,
130 	   &ig4_dump, 0, "Dump controller registers");
131 
132 /*
133  * Clock registers initialization control
134  * 0 - Try read clock registers from ACPI and fallback to p.1.
135  * 1 - Calculate values based on controller type (IC clock rate).
136  * 2 - Use values inherited from DragonflyBSD driver (old behavior).
137  * 3 - Keep clock registers intact.
138  */
139 static int ig4_timings;
140 SYSCTL_INT(_debug, OID_AUTO, ig4_timings, CTLFLAG_RDTUN, &ig4_timings, 0,
141     "Controller timings 0=ACPI, 1=predefined, 2=legacy, 3=do not change");
142 
143 /*
144  * Low-level inline support functions
145  */
146 static __inline void
147 reg_write(ig4iic_softc_t *sc, uint32_t reg, uint32_t value)
148 {
149 	bus_write_4(sc->regs_res, reg, value);
150 	bus_barrier(sc->regs_res, reg, 4, BUS_SPACE_BARRIER_WRITE);
151 }
152 
153 static __inline uint32_t
154 reg_read(ig4iic_softc_t *sc, uint32_t reg)
155 {
156 	uint32_t value;
157 
158 	bus_barrier(sc->regs_res, reg, 4, BUS_SPACE_BARRIER_READ);
159 	value = bus_read_4(sc->regs_res, reg);
160 	return (value);
161 }
162 
163 static void
164 ig4iic_set_intr_mask(ig4iic_softc_t *sc, uint32_t val)
165 {
166 	if (sc->intr_mask != val) {
167 		reg_write(sc, IG4_REG_INTR_MASK, val);
168 		sc->intr_mask = val;
169 	}
170 }
171 
172 static int
173 intrstat2iic(ig4iic_softc_t *sc, uint32_t val)
174 {
175 	uint32_t src;
176 
177 	if (val & IG4_INTR_RX_UNDER)
178 		reg_read(sc, IG4_REG_CLR_RX_UNDER);
179 	if (val & IG4_INTR_RX_OVER)
180 		reg_read(sc, IG4_REG_CLR_RX_OVER);
181 	if (val & IG4_INTR_TX_OVER)
182 		reg_read(sc, IG4_REG_CLR_TX_OVER);
183 
184 	if (val & IG4_INTR_TX_ABRT) {
185 		src = reg_read(sc, IG4_REG_TX_ABRT_SOURCE);
186 		reg_read(sc, IG4_REG_CLR_TX_ABORT);
187 		/* User-requested abort. Not really a error */
188 		if (src & IG4_ABRTSRC_TRANSFER)
189 			return (IIC_ESTATUS);
190 		/* Master has lost arbitration */
191 		if (src & IG4_ABRTSRC_ARBLOST)
192 			return (IIC_EBUSBSY);
193 		/* Did not receive an acknowledge from the remote slave */
194 		if (src & (IG4_ABRTSRC_TXNOACK_ADDR7 |
195 			   IG4_ABRTSRC_TXNOACK_ADDR10_1 |
196 			   IG4_ABRTSRC_TXNOACK_ADDR10_2 |
197 			   IG4_ABRTSRC_TXNOACK_DATA |
198 			   IG4_ABRTSRC_GENCALL_NOACK))
199 			return (IIC_ENOACK);
200 		/* Programming errors */
201 		if (src & (IG4_ABRTSRC_GENCALL_READ |
202 			   IG4_ABRTSRC_NORESTART_START |
203 			   IG4_ABRTSRC_NORESTART_10))
204 			return (IIC_ENOTSUPP);
205 		/* Other errors */
206 		if (src & IG4_ABRTSRC_ACKED_START)
207 			return (IIC_EBUSERR);
208 	}
209 	/*
210 	 * TX_OVER, RX_OVER and RX_UNDER are caused by wrong RX/TX FIFO depth
211 	 * detection or driver's read/write pipelining errors.
212 	 */
213 	if (val & (IG4_INTR_TX_OVER | IG4_INTR_RX_OVER))
214 		return (IIC_EOVERFLOW);
215 	if (val & IG4_INTR_RX_UNDER)
216 		return (IIC_EUNDERFLOW);
217 
218 	return (IIC_NOERR);
219 }
220 
221 /*
222  * Enable or disable the controller and wait for the controller to acknowledge
223  * the state change.
224  */
225 static int
226 set_controller(ig4iic_softc_t *sc, uint32_t ctl)
227 {
228 	int retry;
229 	int error;
230 	uint32_t v;
231 
232 	/*
233 	 * When the controller is enabled, interrupt on STOP detect
234 	 * or receive character ready and clear pending interrupts.
235 	 */
236 	ig4iic_set_intr_mask(sc, 0);
237 	if (ctl & IG4_I2C_ENABLE)
238 		reg_read(sc, IG4_REG_CLR_INTR);
239 
240 	reg_write(sc, IG4_REG_I2C_EN, ctl);
241 	error = IIC_ETIMEOUT;
242 
243 	for (retry = 100; retry > 0; --retry) {
244 		v = reg_read(sc, IG4_REG_ENABLE_STATUS);
245 		if (((v ^ ctl) & IG4_I2C_ENABLE) == 0) {
246 			error = 0;
247 			break;
248 		}
249 		pause("i2cslv", 1);
250 	}
251 	return (error);
252 }
253 
254 /*
255  * Wait up to 25ms for the requested interrupt using a 25uS polling loop.
256  */
257 static int
258 wait_intr(ig4iic_softc_t *sc, uint32_t intr)
259 {
260 	uint32_t v;
261 	int error;
262 	int txlvl = -1;
263 	u_int count_us = 0;
264 	u_int limit_us = 25000; /* 25ms */
265 
266 	for (;;) {
267 		/*
268 		 * Check requested status
269 		 */
270 		v = reg_read(sc, IG4_REG_RAW_INTR_STAT);
271 		error = intrstat2iic(sc, v & IG4_INTR_ERR_MASK);
272 		if (error || (v & intr))
273 			break;
274 
275 		/*
276 		 * When waiting for the transmit FIFO to become empty,
277 		 * reset the timeout if we see a change in the transmit
278 		 * FIFO level as progress is being made.
279 		 */
280 		if (intr & (IG4_INTR_TX_EMPTY | IG4_INTR_STOP_DET)) {
281 			v = reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK;
282 			if (txlvl != v) {
283 				txlvl = v;
284 				count_us = 0;
285 			}
286 		}
287 
288 		/*
289 		 * Stop if we've run out of time.
290 		 */
291 		if (count_us >= limit_us) {
292 			error = IIC_ETIMEOUT;
293 			break;
294 		}
295 
296 		/*
297 		 * When polling is not requested let the interrupt do its work.
298 		 */
299 		if (!DO_POLL(sc)) {
300 			mtx_lock_spin(&sc->io_lock);
301 			ig4iic_set_intr_mask(sc, intr | IG4_INTR_ERR_MASK);
302 			msleep_spin(sc, &sc->io_lock, "i2cwait",
303 				  (hz + 99) / 100); /* sleep up to 10ms */
304 			ig4iic_set_intr_mask(sc, 0);
305 			mtx_unlock_spin(&sc->io_lock);
306 			count_us += 10000;
307 		} else {
308 			DELAY(25);
309 			count_us += 25;
310 		}
311 	}
312 
313 	return (error);
314 }
315 
316 /*
317  * Set the slave address.  The controller must be disabled when
318  * changing the address.
319  *
320  * This operation does not issue anything to the I2C bus but sets
321  * the target address for when the controller later issues a START.
322  */
323 static void
324 set_slave_addr(ig4iic_softc_t *sc, uint8_t slave)
325 {
326 	uint32_t tar;
327 	uint32_t ctl;
328 	int use_10bit;
329 
330 	use_10bit = 0;
331 	if (sc->slave_valid && sc->last_slave == slave &&
332 	    sc->use_10bit == use_10bit) {
333 		return;
334 	}
335 	sc->use_10bit = use_10bit;
336 
337 	/*
338 	 * Wait for TXFIFO to drain before disabling the controller.
339 	 */
340 	wait_intr(sc, IG4_INTR_TX_EMPTY);
341 
342 	set_controller(sc, 0);
343 	ctl = reg_read(sc, IG4_REG_CTL);
344 	ctl &= ~IG4_CTL_10BIT;
345 	ctl |= IG4_CTL_RESTARTEN;
346 
347 	tar = slave;
348 	if (sc->use_10bit) {
349 		tar |= IG4_TAR_10BIT;
350 		ctl |= IG4_CTL_10BIT;
351 	}
352 	reg_write(sc, IG4_REG_CTL, ctl);
353 	reg_write(sc, IG4_REG_TAR_ADD, tar);
354 	set_controller(sc, IG4_I2C_ENABLE);
355 	sc->slave_valid = 1;
356 	sc->last_slave = slave;
357 }
358 
359 /*
360  *				IICBUS API FUNCTIONS
361  */
362 static int
363 ig4iic_xfer_start(ig4iic_softc_t *sc, uint16_t slave, bool repeated_start)
364 {
365 	set_slave_addr(sc, slave >> 1);
366 
367 	if (!repeated_start) {
368 		/*
369 		 * Clear any previous TX/RX FIFOs overflow/underflow bits
370 		 * and I2C bus STOP condition.
371 		 */
372 		reg_read(sc, IG4_REG_CLR_INTR);
373 	}
374 
375 	return (0);
376 }
377 
378 static bool
379 ig4iic_xfer_is_started(ig4iic_softc_t *sc)
380 {
381 	/*
382 	 * It requires that no IG4_REG_CLR_INTR or IG4_REG_CLR_START/STOP_DET
383 	 * register reads is issued after START condition.
384 	 */
385 	return ((reg_read(sc, IG4_REG_RAW_INTR_STAT) &
386 	    (IG4_INTR_START_DET | IG4_INTR_STOP_DET)) == IG4_INTR_START_DET);
387 }
388 
389 static int
390 ig4iic_xfer_abort(ig4iic_softc_t *sc)
391 {
392 	int error;
393 
394 	/* Request send of STOP condition and flush of TX FIFO */
395 	set_controller(sc, IG4_I2C_ABORT | IG4_I2C_ENABLE);
396 	/*
397 	 * Wait for the TX_ABRT interrupt with ABRTSRC_TRANSFER
398 	 * bit set in TX_ABRT_SOURCE register.
399 	 */
400 	error = wait_intr(sc, IG4_INTR_STOP_DET);
401 	set_controller(sc, IG4_I2C_ENABLE);
402 
403 	return (error == IIC_ESTATUS ? 0 : error);
404 }
405 
406 /*
407  * Amount of unread data before next burst to get better I2C bus utilization.
408  * 2 bytes is enough in FAST mode. 8 bytes is better in FAST+ and HIGH modes.
409  * Intel-recommended value is 16 for DMA transfers with 64-byte depth FIFOs.
410  */
411 #define	IG4_FIFO_LOWAT	2
412 
413 static int
414 ig4iic_read(ig4iic_softc_t *sc, uint8_t *buf, uint16_t len,
415     bool repeated_start, bool stop)
416 {
417 	uint32_t cmd;
418 	int requested = 0;
419 	int received = 0;
420 	int burst, target, lowat = 0;
421 	int error;
422 
423 	if (len == 0)
424 		return (0);
425 
426 	while (received < len) {
427 		burst = sc->cfg.txfifo_depth -
428 		    (reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
429 		if (burst <= 0) {
430 			error = wait_intr(sc, IG4_INTR_TX_EMPTY);
431 			if (error)
432 				break;
433 			burst = sc->cfg.txfifo_depth;
434 		}
435 		/* Ensure we have enough free space in RXFIFO */
436 		burst = MIN(burst, sc->cfg.rxfifo_depth - lowat);
437 		target = MIN(requested + burst, (int)len);
438 		while (requested < target) {
439 			cmd = IG4_DATA_COMMAND_RD;
440 			if (repeated_start && requested == 0)
441 				cmd |= IG4_DATA_RESTART;
442 			if (stop && requested == len - 1)
443 				cmd |= IG4_DATA_STOP;
444 			reg_write(sc, IG4_REG_DATA_CMD, cmd);
445 			requested++;
446 		}
447 		/* Leave some data queued to maintain the hardware pipeline */
448 		lowat = 0;
449 		if (requested != len && requested - received > IG4_FIFO_LOWAT)
450 			lowat = IG4_FIFO_LOWAT;
451 		/* After TXFLR fills up, clear it by reading available data */
452 		while (received < requested - lowat) {
453 			burst = MIN((int)len - received,
454 			    reg_read(sc, IG4_REG_RXFLR) & IG4_FIFOLVL_MASK);
455 			if (burst > 0) {
456 				while (burst--)
457 					buf[received++] = 0xFF &
458 					    reg_read(sc, IG4_REG_DATA_CMD);
459 			} else {
460 				error = wait_intr(sc, IG4_INTR_RX_FULL);
461 				if (error)
462 					goto out;
463 			}
464 		}
465 	}
466 out:
467 	return (error);
468 }
469 
470 static int
471 ig4iic_write(ig4iic_softc_t *sc, uint8_t *buf, uint16_t len,
472     bool repeated_start, bool stop)
473 {
474 	uint32_t cmd;
475 	int sent = 0;
476 	int burst, target;
477 	int error;
478 	bool lowat_set = false;
479 
480 	if (len == 0)
481 		return (0);
482 
483 	while (sent < len) {
484 		burst = sc->cfg.txfifo_depth -
485 		    (reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
486 		target = MIN(sent + burst, (int)len);
487 		/* Leave some data queued to maintain the hardware pipeline */
488 		if (!lowat_set && target != len) {
489 			lowat_set = true;
490 			reg_write(sc, IG4_REG_TX_TL, IG4_FIFO_LOWAT);
491 		}
492 		while(sent < target) {
493 			cmd = buf[sent];
494 			if (repeated_start && sent == 0)
495 				cmd |= IG4_DATA_RESTART;
496 			if (stop && sent == len - 1)
497 				cmd |= IG4_DATA_STOP;
498 			reg_write(sc, IG4_REG_DATA_CMD, cmd);
499 			sent++;
500 		}
501 		if (sent < len) {
502 			error = wait_intr(sc, IG4_INTR_TX_EMPTY);
503 			if (error)
504 				break;
505 		}
506 	}
507 	if (lowat_set)
508 		reg_write(sc, IG4_REG_TX_TL, 0);
509 
510 	return (error);
511 }
512 
513 int
514 ig4iic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
515 {
516 	ig4iic_softc_t *sc = device_get_softc(dev);
517 	const char *reason = NULL;
518 	uint32_t i;
519 	int error;
520 	int unit;
521 	bool rpstart;
522 	bool stop;
523 	bool allocated;
524 
525 	/*
526 	 * The hardware interface imposes limits on allowed I2C messages.
527 	 * It is not possible to explicitly send a start or stop.
528 	 * They are automatically sent (or not sent, depending on the
529 	 * configuration) when a data byte is transferred.
530 	 * For this reason it's impossible to send a message with no data
531 	 * at all (like an SMBus quick message).
532 	 * The start condition is automatically generated after the stop
533 	 * condition, so it's impossible to not have a start after a stop.
534 	 * The repeated start condition is automatically sent if a change
535 	 * of the transfer direction happens, so it's impossible to have
536 	 * a change of direction without a (repeated) start.
537 	 * The repeated start can be forced even without the change of
538 	 * direction.
539 	 * Changing the target slave address requires resetting the hardware
540 	 * state, so it's impossible to do that without the stop followed
541 	 * by the start.
542 	 */
543 	for (i = 0; i < nmsgs; i++) {
544 #if 0
545 		if (i == 0 && (msgs[i].flags & IIC_M_NOSTART) != 0) {
546 			reason = "first message without start";
547 			break;
548 		}
549 		if (i == nmsgs - 1 && (msgs[i].flags & IIC_M_NOSTOP) != 0) {
550 			reason = "last message without stop";
551 			break;
552 		}
553 #endif
554 		if (msgs[i].len == 0) {
555 			reason = "message with no data";
556 			break;
557 		}
558 		if (i > 0) {
559 			if ((msgs[i].flags & IIC_M_NOSTART) != 0 &&
560 			    (msgs[i - 1].flags & IIC_M_NOSTOP) == 0) {
561 				reason = "stop not followed by start";
562 				break;
563 			}
564 			if ((msgs[i - 1].flags & IIC_M_NOSTOP) != 0 &&
565 			    msgs[i].slave != msgs[i - 1].slave) {
566 				reason = "change of slave without stop";
567 				break;
568 			}
569 			if ((msgs[i].flags & IIC_M_NOSTART) != 0 &&
570 			    (msgs[i].flags & IIC_M_RD) !=
571 			    (msgs[i - 1].flags & IIC_M_RD)) {
572 				reason = "change of direction without repeated"
573 				    " start";
574 				break;
575 			}
576 		}
577 	}
578 	if (reason != NULL) {
579 		if (bootverbose)
580 			device_printf(dev, "%s\n", reason);
581 		return (IIC_ENOTSUPP);
582 	}
583 
584 	/* Check if device is already allocated with iicbus_request_bus() */
585 	allocated = sx_xlocked(&sc->call_lock) != 0;
586 	if (!allocated)
587 		sx_xlock(&sc->call_lock);
588 
589 	/* Debugging - dump registers. */
590 	if (ig4_dump) {
591 		unit = device_get_unit(dev);
592 		if (ig4_dump & (1 << unit)) {
593 			ig4_dump &= ~(1 << unit);
594 			ig4iic_dump(sc);
595 		}
596 	}
597 
598 	/*
599 	 * Clear any previous abort condition that may have been holding
600 	 * the txfifo in reset.
601 	 */
602 	reg_read(sc, IG4_REG_CLR_TX_ABORT);
603 
604 	rpstart = false;
605 	error = 0;
606 	for (i = 0; i < nmsgs; i++) {
607 		if ((msgs[i].flags & IIC_M_NOSTART) == 0) {
608 			error = ig4iic_xfer_start(sc, msgs[i].slave, rpstart);
609 		} else {
610 			if (!sc->slave_valid ||
611 			    (msgs[i].slave >> 1) != sc->last_slave) {
612 				device_printf(dev, "start condition suppressed"
613 				    "but slave address is not set up");
614 				error = EINVAL;
615 				break;
616 			}
617 			rpstart = false;
618 		}
619 		if (error != 0)
620 			break;
621 
622 		stop = (msgs[i].flags & IIC_M_NOSTOP) == 0;
623 		if (msgs[i].flags & IIC_M_RD)
624 			error = ig4iic_read(sc, msgs[i].buf, msgs[i].len,
625 			    rpstart, stop);
626 		else
627 			error = ig4iic_write(sc, msgs[i].buf, msgs[i].len,
628 			    rpstart, stop);
629 
630 		/* Wait for error or stop condition occurred on the I2C bus */
631 		if (stop && error == 0) {
632 			error = wait_intr(sc, IG4_INTR_STOP_DET);
633 			if (error == 0)
634 				reg_read(sc, IG4_REG_CLR_INTR);
635 		}
636 
637 		if (error != 0) {
638 			/*
639 			 * Send STOP condition if it's not done yet and flush
640 			 * both FIFOs. Do a controller soft reset if transfer
641 			 * abort is failed.
642 			 */
643 			if (ig4iic_xfer_is_started(sc) &&
644 			    ig4iic_xfer_abort(sc) != 0) {
645 				device_printf(sc->dev, "Failed to abort "
646 				    "transfer. Do the controller reset.\n");
647 				ig4iic_set_config(sc, true);
648 			} else {
649 				while (reg_read(sc, IG4_REG_I2C_STA) &
650 				    IG4_STATUS_RX_NOTEMPTY)
651 					reg_read(sc, IG4_REG_DATA_CMD);
652 				reg_read(sc, IG4_REG_TX_ABRT_SOURCE);
653 				reg_read(sc, IG4_REG_CLR_INTR);
654 			}
655 			break;
656 		}
657 
658 		rpstart = !stop;
659 	}
660 
661 	if (!allocated)
662 		sx_unlock(&sc->call_lock);
663 	return (error);
664 }
665 
666 int
667 ig4iic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
668 {
669 	ig4iic_softc_t *sc = device_get_softc(dev);
670 	bool allocated;
671 
672 	allocated = sx_xlocked(&sc->call_lock) != 0;
673 	if (!allocated)
674 		sx_xlock(&sc->call_lock);
675 
676 	/* TODO handle speed configuration? */
677 	if (oldaddr != NULL)
678 		*oldaddr = sc->last_slave << 1;
679 	set_slave_addr(sc, addr >> 1);
680 	if (addr == IIC_UNKNOWN)
681 		sc->slave_valid = false;
682 
683 	if (!allocated)
684 		sx_unlock(&sc->call_lock);
685 	return (0);
686 }
687 
688 int
689 ig4iic_callback(device_t dev, int index, caddr_t data)
690 {
691 	ig4iic_softc_t *sc = device_get_softc(dev);
692 	int error = 0;
693 	int how;
694 
695 	switch (index) {
696 	case IIC_REQUEST_BUS:
697 		/* force polling if ig4iic is requested with IIC_DONTWAIT */
698 		how = *(int *)data;
699 		if ((how & IIC_WAIT) == 0) {
700 			if (sx_try_xlock(&sc->call_lock) == 0)
701 				error = IIC_EBUSBSY;
702 			else
703 				sc->poll = true;
704 		} else
705 			sx_xlock(&sc->call_lock);
706 		break;
707 
708 	case IIC_RELEASE_BUS:
709 		sc->poll = false;
710 		sx_unlock(&sc->call_lock);
711 		break;
712 
713 	default:
714 		error = errno2iic(EINVAL);
715 	}
716 
717 	return (error);
718 }
719 
720 /*
721  * Clock register values can be calculated with following rough equations:
722  * SCL_HCNT = ceil(IC clock rate * tHIGH)
723  * SCL_LCNT = ceil(IC clock rate * tLOW)
724  * SDA_HOLD = ceil(IC clock rate * SDA hold time)
725  * Precise equations take signal's falling, rising and spike suppression
726  * times in to account. They can be found in Synopsys or Intel documentation.
727  *
728  * Here we snarf formulas and defaults from Linux driver to be able to use
729  * timing values provided by Intel LPSS driver "as is".
730  */
731 static int
732 ig4iic_clk_params(const struct ig4_hw *hw, int speed,
733     uint16_t *scl_hcnt, uint16_t *scl_lcnt, uint16_t *sda_hold)
734 {
735 	uint32_t thigh, tlow, tf_max;	/* nsec */
736 	uint32_t sda_fall_time;		/* nsec */
737         uint32_t scl_fall_time;		/* nsec */
738 
739 	switch (speed) {
740 	case IG4_CTL_SPEED_STD:
741 		thigh = IG4_SPEED_STD_THIGH;
742 		tlow = IG4_SPEED_STD_TLOW;
743 		tf_max = IG4_SPEED_STD_TF_MAX;
744 		break;
745 
746 	case IG4_CTL_SPEED_FAST:
747 		thigh = IG4_SPEED_FAST_THIGH;
748 		tlow = IG4_SPEED_FAST_TLOW;
749 		tf_max = IG4_SPEED_FAST_TF_MAX;
750 		break;
751 
752 	default:
753 		return (EINVAL);
754 	}
755 
756 	/* Use slowest falling time defaults to be on the safe side */
757 	sda_fall_time = hw->sda_fall_time == 0 ? tf_max : hw->sda_fall_time;
758 	*scl_hcnt = (uint16_t)
759 	    ((hw->ic_clock_rate * (thigh + sda_fall_time) + 500) / 1000 - 3);
760 
761 	scl_fall_time = hw->scl_fall_time == 0 ? tf_max : hw->scl_fall_time;
762 	*scl_lcnt = (uint16_t)
763 	    ((hw->ic_clock_rate * (tlow + scl_fall_time) + 500) / 1000 - 1);
764 
765 	/*
766 	 * There is no "known good" default value for tHD;DAT so keep SDA_HOLD
767 	 * intact if sda_hold_time value is not provided.
768 	 */
769 	if (hw->sda_hold_time != 0)
770 		*sda_hold = (uint16_t)
771 		    ((hw->ic_clock_rate * hw->sda_hold_time + 500) / 1000);
772 
773 	return (0);
774 }
775 
776 #ifdef DEV_ACPI
777 static ACPI_STATUS
778 ig4iic_acpi_params(ACPI_HANDLE handle, char *method,
779     uint16_t *scl_hcnt, uint16_t *scl_lcnt, uint16_t *sda_hold)
780 {
781 	ACPI_BUFFER buf;
782 	ACPI_OBJECT *obj, *elems;
783 	ACPI_STATUS status;
784 
785 	buf.Pointer = NULL;
786 	buf.Length = ACPI_ALLOCATE_BUFFER;
787 
788 	status = AcpiEvaluateObject(handle, method, NULL, &buf);
789 	if (ACPI_FAILURE(status))
790 		return (status);
791 
792 	status = AE_TYPE;
793 	obj = (ACPI_OBJECT *)buf.Pointer;
794 	if (obj->Type == ACPI_TYPE_PACKAGE && obj->Package.Count == 3) {
795 		elems = obj->Package.Elements;
796 		*scl_hcnt = elems[0].Integer.Value & IG4_SCL_CLOCK_MASK;
797 		*scl_lcnt = elems[1].Integer.Value & IG4_SCL_CLOCK_MASK;
798 		*sda_hold = elems[2].Integer.Value & IG4_SDA_TX_HOLD_MASK;
799 		status = AE_OK;
800 	}
801 
802 	AcpiOsFree(obj);
803 
804 	return (status);
805 }
806 #endif /* DEV_ACPI */
807 
808 static void
809 ig4iic_get_config(ig4iic_softc_t *sc)
810 {
811 	const struct ig4_hw *hw;
812 	uint32_t v;
813 #ifdef DEV_ACPI
814 	ACPI_HANDLE handle;
815 #endif
816 	/* Fetch default hardware config from controller */
817 	sc->cfg.version = reg_read(sc, IG4_REG_COMP_VER);
818 	sc->cfg.bus_speed = reg_read(sc, IG4_REG_CTL) & IG4_CTL_SPEED_MASK;
819 	sc->cfg.ss_scl_hcnt =
820 	    reg_read(sc, IG4_REG_SS_SCL_HCNT) & IG4_SCL_CLOCK_MASK;
821 	sc->cfg.ss_scl_lcnt =
822 	    reg_read(sc, IG4_REG_SS_SCL_LCNT) & IG4_SCL_CLOCK_MASK;
823 	sc->cfg.fs_scl_hcnt =
824 	    reg_read(sc, IG4_REG_FS_SCL_HCNT) & IG4_SCL_CLOCK_MASK;
825 	sc->cfg.fs_scl_lcnt =
826 	    reg_read(sc, IG4_REG_FS_SCL_LCNT) & IG4_SCL_CLOCK_MASK;
827 	sc->cfg.ss_sda_hold = sc->cfg.fs_sda_hold =
828 	    reg_read(sc, IG4_REG_SDA_HOLD) & IG4_SDA_TX_HOLD_MASK;
829 
830 	if (sc->cfg.bus_speed != IG4_CTL_SPEED_STD)
831 		sc->cfg.bus_speed = IG4_CTL_SPEED_FAST;
832 
833 	/* REG_COMP_PARAM1 is not documented in latest Intel specs */
834 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
835 		v = reg_read(sc, IG4_REG_COMP_PARAM1);
836 		if (IG4_PARAM1_TXFIFO_DEPTH(v) != 0)
837 			sc->cfg.txfifo_depth = IG4_PARAM1_TXFIFO_DEPTH(v);
838 		if (IG4_PARAM1_RXFIFO_DEPTH(v) != 0)
839 			sc->cfg.rxfifo_depth = IG4_PARAM1_RXFIFO_DEPTH(v);
840 	} else {
841 		/*
842 		 * Hardware does not allow FIFO Threshold Levels value to be
843 		 * set larger than the depth of the buffer. If an attempt is
844 		 * made to do that, the actual value set will be the maximum
845 		 * depth of the buffer.
846 		 */
847 		v = reg_read(sc, IG4_REG_TX_TL);
848 		reg_write(sc, IG4_REG_TX_TL, v | IG4_FIFO_MASK);
849 		sc->cfg.txfifo_depth =
850 		    (reg_read(sc, IG4_REG_TX_TL) & IG4_FIFO_MASK) + 1;
851 		reg_write(sc, IG4_REG_TX_TL, v);
852 		v = reg_read(sc, IG4_REG_RX_TL);
853 		reg_write(sc, IG4_REG_RX_TL, v | IG4_FIFO_MASK);
854 		sc->cfg.rxfifo_depth =
855 		    (reg_read(sc, IG4_REG_RX_TL) & IG4_FIFO_MASK) + 1;
856 		reg_write(sc, IG4_REG_RX_TL, v);
857 	}
858 
859 	/* Override hardware config with IC_clock-based counter values */
860 	if (ig4_timings < 2 && sc->version < nitems(ig4iic_hw)) {
861 		hw = &ig4iic_hw[sc->version];
862 		sc->cfg.bus_speed = IG4_CTL_SPEED_FAST;
863 		ig4iic_clk_params(hw, IG4_CTL_SPEED_STD, &sc->cfg.ss_scl_hcnt,
864 		    &sc->cfg.ss_scl_lcnt, &sc->cfg.ss_sda_hold);
865 		ig4iic_clk_params(hw, IG4_CTL_SPEED_FAST, &sc->cfg.fs_scl_hcnt,
866 		    &sc->cfg.fs_scl_lcnt, &sc->cfg.fs_sda_hold);
867 		if (hw->txfifo_depth != 0)
868 			sc->cfg.txfifo_depth = hw->txfifo_depth;
869 		if (hw->rxfifo_depth != 0)
870 			sc->cfg.rxfifo_depth = hw->rxfifo_depth;
871 	} else if (ig4_timings == 2) {
872 		/*
873 		 * Timings of original ig4 driver:
874 		 * Program based on a 25000 Hz clock.  This is a bit of a
875 		 * hack (obviously).  The defaults are 400 and 470 for standard
876 		 * and 60 and 130 for fast.  The defaults for standard fail
877 		 * utterly (presumably cause an abort) because the clock time
878 		 * is ~18.8ms by default.  This brings it down to ~4ms.
879 		 */
880 		sc->cfg.bus_speed = IG4_CTL_SPEED_STD;
881 		sc->cfg.ss_scl_hcnt = sc->cfg.fs_scl_hcnt = 100;
882 		sc->cfg.ss_scl_lcnt = sc->cfg.fs_scl_lcnt = 125;
883 		if (sc->version == IG4_SKYLAKE)
884 			sc->cfg.ss_sda_hold = sc->cfg.fs_sda_hold = 28;
885 	}
886 
887 #ifdef DEV_ACPI
888 	/* Evaluate SSCN and FMCN ACPI methods to fetch timings */
889 	if (ig4_timings == 0 && (handle = acpi_get_handle(sc->dev)) != NULL) {
890 		ig4iic_acpi_params(handle, "SSCN", &sc->cfg.ss_scl_hcnt,
891 		    &sc->cfg.ss_scl_lcnt, &sc->cfg.ss_sda_hold);
892 		ig4iic_acpi_params(handle, "FMCN", &sc->cfg.fs_scl_hcnt,
893 		    &sc->cfg.fs_scl_lcnt, &sc->cfg.fs_sda_hold);
894 	}
895 #endif
896 
897 	if (bootverbose) {
898 		device_printf(sc->dev, "Controller parameters:\n");
899 		printf("  Speed: %s\n",
900 		    sc->cfg.bus_speed == IG4_CTL_SPEED_STD ? "Std" : "Fast");
901 		printf("  Regs:  HCNT  :LCNT  :SDAHLD\n");
902 		printf("  Std:   0x%04hx:0x%04hx:0x%04hx\n",
903 		    sc->cfg.ss_scl_hcnt, sc->cfg.ss_scl_lcnt,
904 		    sc->cfg.ss_sda_hold);
905 		printf("  Fast:  0x%04hx:0x%04hx:0x%04hx\n",
906 		    sc->cfg.fs_scl_hcnt, sc->cfg.fs_scl_lcnt,
907 		    sc->cfg.fs_sda_hold);
908 		printf("  FIFO:  RX:0x%04x: TX:0x%04x\n",
909 		    sc->cfg.rxfifo_depth, sc->cfg.txfifo_depth);
910 	}
911 }
912 
913 static int
914 ig4iic_set_config(ig4iic_softc_t *sc, bool reset)
915 {
916 	uint32_t v;
917 
918 	v = reg_read(sc, IG4_REG_DEVIDLE_CTRL);
919 	if (IG4_HAS_ADDREGS(sc->version) && (v & IG4_RESTORE_REQUIRED)) {
920 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, IG4_DEVICE_IDLE | IG4_RESTORE_REQUIRED);
921 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, 0);
922 		pause("i2crst", 1);
923 		reset = true;
924 	}
925 
926 	if ((sc->version == IG4_HASWELL || sc->version == IG4_ATOM) && reset) {
927 		reg_write(sc, IG4_REG_RESETS_HSW, IG4_RESETS_ASSERT_HSW);
928 		reg_write(sc, IG4_REG_RESETS_HSW, IG4_RESETS_DEASSERT_HSW);
929 	} else if (IG4_HAS_ADDREGS(sc->version) && reset) {
930 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_ASSERT_SKL);
931 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_DEASSERT_SKL);
932 	}
933 
934 	if (sc->version == IG4_ATOM)
935 		v = reg_read(sc, IG4_REG_COMP_TYPE);
936 
937 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
938 		v = reg_read(sc, IG4_REG_COMP_PARAM1);
939 		v = reg_read(sc, IG4_REG_GENERAL);
940 		/*
941 		 * The content of IG4_REG_GENERAL is different for each
942 		 * controller version.
943 		 */
944 		if (sc->version == IG4_HASWELL &&
945 		    (v & IG4_GENERAL_SWMODE) == 0) {
946 			v |= IG4_GENERAL_SWMODE;
947 			reg_write(sc, IG4_REG_GENERAL, v);
948 			v = reg_read(sc, IG4_REG_GENERAL);
949 		}
950 	}
951 
952 	if (sc->version == IG4_HASWELL) {
953 		v = reg_read(sc, IG4_REG_SW_LTR_VALUE);
954 		v = reg_read(sc, IG4_REG_AUTO_LTR_VALUE);
955 	} else if (IG4_HAS_ADDREGS(sc->version)) {
956 		v = reg_read(sc, IG4_REG_ACTIVE_LTR_VALUE);
957 		v = reg_read(sc, IG4_REG_IDLE_LTR_VALUE);
958 	}
959 
960 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
961 		v = reg_read(sc, IG4_REG_COMP_VER);
962 		if (v < IG4_COMP_MIN_VER)
963 			return(ENXIO);
964 	}
965 
966 	if (set_controller(sc, 0)) {
967 		device_printf(sc->dev, "controller error during attach-1\n");
968 		return (ENXIO);
969 	}
970 
971 	reg_read(sc, IG4_REG_CLR_INTR);
972 	reg_write(sc, IG4_REG_INTR_MASK, 0);
973 	sc->intr_mask = 0;
974 
975 	reg_write(sc, IG4_REG_SS_SCL_HCNT, sc->cfg.ss_scl_hcnt);
976 	reg_write(sc, IG4_REG_SS_SCL_LCNT, sc->cfg.ss_scl_lcnt);
977 	reg_write(sc, IG4_REG_FS_SCL_HCNT, sc->cfg.fs_scl_hcnt);
978 	reg_write(sc, IG4_REG_FS_SCL_LCNT, sc->cfg.fs_scl_lcnt);
979 	reg_write(sc, IG4_REG_SDA_HOLD,
980 	    (sc->cfg.bus_speed  & IG4_CTL_SPEED_MASK) == IG4_CTL_SPEED_STD ?
981 	      sc->cfg.ss_sda_hold : sc->cfg.fs_sda_hold);
982 
983 	/*
984 	 * Use a threshold of 1 so we get interrupted on each character,
985 	 * allowing us to use mtx_sleep() in our poll code.  Not perfect
986 	 * but this is better than using DELAY() for receiving data.
987 	 *
988 	 * See ig4_var.h for details on interrupt handler synchronization.
989 	 */
990 	reg_write(sc, IG4_REG_RX_TL, 0);
991 	reg_write(sc, IG4_REG_TX_TL, 0);
992 
993 	reg_write(sc, IG4_REG_CTL,
994 		  IG4_CTL_MASTER |
995 		  IG4_CTL_SLAVE_DISABLE |
996 		  IG4_CTL_RESTARTEN |
997 		  (sc->cfg.bus_speed & IG4_CTL_SPEED_MASK));
998 
999 	/* Force setting of the target address on the next transfer */
1000 	sc->slave_valid = 0;
1001 
1002 	return (0);
1003 }
1004 
1005 /*
1006  * Called from ig4iic_pci_attach/detach()
1007  */
1008 int
1009 ig4iic_attach(ig4iic_softc_t *sc)
1010 {
1011 	int error;
1012 
1013 	mtx_init(&sc->io_lock, "IG4 I/O lock", NULL, MTX_SPIN);
1014 	sx_init(&sc->call_lock, "IG4 call lock");
1015 
1016 	ig4iic_get_config(sc);
1017 
1018 	error = ig4iic_set_config(sc, IG4_HAS_ADDREGS(sc->version));
1019 	if (error)
1020 		goto done;
1021 
1022 	sc->iicbus = device_add_child(sc->dev, "iicbus", -1);
1023 	if (sc->iicbus == NULL) {
1024 		device_printf(sc->dev, "iicbus driver not found\n");
1025 		error = ENXIO;
1026 		goto done;
1027 	}
1028 
1029 	if (set_controller(sc, IG4_I2C_ENABLE)) {
1030 		device_printf(sc->dev, "controller error during attach-2\n");
1031 		error = ENXIO;
1032 		goto done;
1033 	}
1034 	if (set_controller(sc, 0)) {
1035 		device_printf(sc->dev, "controller error during attach-3\n");
1036 		error = ENXIO;
1037 		goto done;
1038 	}
1039 	error = bus_setup_intr(sc->dev, sc->intr_res, INTR_TYPE_MISC | INTR_MPSAFE,
1040 			       ig4iic_intr, NULL, sc, &sc->intr_handle);
1041 	if (error) {
1042 		device_printf(sc->dev,
1043 			      "Unable to setup irq: error %d\n", error);
1044 	}
1045 
1046 	error = bus_generic_attach(sc->dev);
1047 	if (error) {
1048 		device_printf(sc->dev,
1049 			      "failed to attach child: error %d\n", error);
1050 	}
1051 
1052 done:
1053 	return (error);
1054 }
1055 
1056 int
1057 ig4iic_detach(ig4iic_softc_t *sc)
1058 {
1059 	int error;
1060 
1061 	if (device_is_attached(sc->dev)) {
1062 		error = bus_generic_detach(sc->dev);
1063 		if (error)
1064 			return (error);
1065 	}
1066 	if (sc->iicbus)
1067 		device_delete_child(sc->dev, sc->iicbus);
1068 	if (sc->intr_handle)
1069 		bus_teardown_intr(sc->dev, sc->intr_res, sc->intr_handle);
1070 
1071 	sx_xlock(&sc->call_lock);
1072 
1073 	sc->iicbus = NULL;
1074 	sc->intr_handle = NULL;
1075 	reg_write(sc, IG4_REG_INTR_MASK, 0);
1076 	set_controller(sc, 0);
1077 
1078 	sx_xunlock(&sc->call_lock);
1079 
1080 	mtx_destroy(&sc->io_lock);
1081 	sx_destroy(&sc->call_lock);
1082 
1083 	return (0);
1084 }
1085 
1086 int
1087 ig4iic_suspend(ig4iic_softc_t *sc)
1088 {
1089 	int error;
1090 
1091 	/* suspend all children */
1092 	error = bus_generic_suspend(sc->dev);
1093 
1094 	sx_xlock(&sc->call_lock);
1095 	set_controller(sc, 0);
1096 	if (IG4_HAS_ADDREGS(sc->version)) {
1097 		/*
1098 		 * Place the device in the idle state, just to be safe
1099 		 */
1100 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, IG4_DEVICE_IDLE);
1101 		/*
1102 		 * Controller can become dysfunctional if I2C lines are pulled
1103 		 * down when suspend procedure turns off power to I2C device.
1104 		 * Place device in the reset state to avoid this.
1105 		 */
1106 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_ASSERT_SKL);
1107 	}
1108 	sx_xunlock(&sc->call_lock);
1109 
1110 	return (error);
1111 }
1112 
1113 int ig4iic_resume(ig4iic_softc_t *sc)
1114 {
1115 	int error;
1116 
1117 	sx_xlock(&sc->call_lock);
1118 	if (ig4iic_set_config(sc, IG4_HAS_ADDREGS(sc->version)))
1119 		device_printf(sc->dev, "controller error during resume\n");
1120 	sx_xunlock(&sc->call_lock);
1121 
1122 	error = bus_generic_resume(sc->dev);
1123 
1124 	return (error);
1125 }
1126 
1127 /*
1128  * Interrupt Operation, see ig4_var.h for locking semantics.
1129  */
1130 static int
1131 ig4iic_intr(void *cookie)
1132 {
1133 	ig4iic_softc_t *sc = cookie;
1134 	int retval = FILTER_STRAY;
1135 
1136 	mtx_lock_spin(&sc->io_lock);
1137 	/* Ignore stray interrupts */
1138 	if (sc->intr_mask != 0 && reg_read(sc, IG4_REG_INTR_STAT) != 0) {
1139 		/* Interrupt bits are cleared in wait_intr() loop */
1140 		ig4iic_set_intr_mask(sc, 0);
1141 		wakeup(sc);
1142 		retval = FILTER_HANDLED;
1143 	}
1144 	mtx_unlock_spin(&sc->io_lock);
1145 
1146 	return (retval);
1147 }
1148 
1149 #define REGDUMP(sc, reg)	\
1150 	device_printf(sc->dev, "  %-23s %08x\n", #reg, reg_read(sc, reg))
1151 
1152 static void
1153 ig4iic_dump(ig4iic_softc_t *sc)
1154 {
1155 	device_printf(sc->dev, "ig4iic register dump:\n");
1156 	REGDUMP(sc, IG4_REG_CTL);
1157 	REGDUMP(sc, IG4_REG_TAR_ADD);
1158 	REGDUMP(sc, IG4_REG_SS_SCL_HCNT);
1159 	REGDUMP(sc, IG4_REG_SS_SCL_LCNT);
1160 	REGDUMP(sc, IG4_REG_FS_SCL_HCNT);
1161 	REGDUMP(sc, IG4_REG_FS_SCL_LCNT);
1162 	REGDUMP(sc, IG4_REG_INTR_STAT);
1163 	REGDUMP(sc, IG4_REG_INTR_MASK);
1164 	REGDUMP(sc, IG4_REG_RAW_INTR_STAT);
1165 	REGDUMP(sc, IG4_REG_RX_TL);
1166 	REGDUMP(sc, IG4_REG_TX_TL);
1167 	REGDUMP(sc, IG4_REG_I2C_EN);
1168 	REGDUMP(sc, IG4_REG_I2C_STA);
1169 	REGDUMP(sc, IG4_REG_TXFLR);
1170 	REGDUMP(sc, IG4_REG_RXFLR);
1171 	REGDUMP(sc, IG4_REG_SDA_HOLD);
1172 	REGDUMP(sc, IG4_REG_TX_ABRT_SOURCE);
1173 	REGDUMP(sc, IG4_REG_SLV_DATA_NACK);
1174 	REGDUMP(sc, IG4_REG_DMA_CTRL);
1175 	REGDUMP(sc, IG4_REG_DMA_TDLR);
1176 	REGDUMP(sc, IG4_REG_DMA_RDLR);
1177 	REGDUMP(sc, IG4_REG_SDA_SETUP);
1178 	REGDUMP(sc, IG4_REG_ENABLE_STATUS);
1179 	REGDUMP(sc, IG4_REG_COMP_PARAM1);
1180 	REGDUMP(sc, IG4_REG_COMP_VER);
1181 	if (sc->version == IG4_ATOM) {
1182 		REGDUMP(sc, IG4_REG_COMP_TYPE);
1183 		REGDUMP(sc, IG4_REG_CLK_PARMS);
1184 	}
1185 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
1186 		REGDUMP(sc, IG4_REG_RESETS_HSW);
1187 		REGDUMP(sc, IG4_REG_GENERAL);
1188 	} else if (sc->version == IG4_SKYLAKE) {
1189 		REGDUMP(sc, IG4_REG_RESETS_SKL);
1190 	}
1191 	if (sc->version == IG4_HASWELL) {
1192 		REGDUMP(sc, IG4_REG_SW_LTR_VALUE);
1193 		REGDUMP(sc, IG4_REG_AUTO_LTR_VALUE);
1194 	} else if (IG4_HAS_ADDREGS(sc->version)) {
1195 		REGDUMP(sc, IG4_REG_ACTIVE_LTR_VALUE);
1196 		REGDUMP(sc, IG4_REG_IDLE_LTR_VALUE);
1197 	}
1198 }
1199 #undef REGDUMP
1200 
1201 devclass_t ig4iic_devclass;
1202 
1203 DRIVER_MODULE(iicbus, ig4iic, iicbus_driver, iicbus_devclass, NULL, NULL);
1204 #ifdef DEV_ACPI
1205 DRIVER_MODULE(acpi_iicbus, ig4iic, acpi_iicbus_driver, iicbus_devclass, NULL,
1206     NULL);
1207 #endif
1208 MODULE_DEPEND(ig4iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
1209 MODULE_VERSION(ig4iic, 1);
1210