xref: /freebsd/sys/dev/ichiic/ig4_iic.c (revision c3c73b4f0a91d2806e1a632b75f769fb4fa89576)
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 };
129 
130 static int ig4iic_set_config(ig4iic_softc_t *sc, bool reset);
131 static driver_filter_t ig4iic_intr;
132 static void ig4iic_dump(ig4iic_softc_t *sc);
133 
134 static int ig4_dump;
135 SYSCTL_INT(_debug, OID_AUTO, ig4_dump, CTLFLAG_RW,
136 	   &ig4_dump, 0, "Dump controller registers");
137 
138 /*
139  * Clock registers initialization control
140  * 0 - Try read clock registers from ACPI and fallback to p.1.
141  * 1 - Calculate values based on controller type (IC clock rate).
142  * 2 - Use values inherited from DragonflyBSD driver (old behavior).
143  * 3 - Keep clock registers intact.
144  */
145 static int ig4_timings;
146 SYSCTL_INT(_debug, OID_AUTO, ig4_timings, CTLFLAG_RDTUN, &ig4_timings, 0,
147     "Controller timings 0=ACPI, 1=predefined, 2=legacy, 3=do not change");
148 
149 /*
150  * Low-level inline support functions
151  */
152 static __inline void
153 reg_write(ig4iic_softc_t *sc, uint32_t reg, uint32_t value)
154 {
155 	bus_write_4(sc->regs_res, reg, value);
156 	bus_barrier(sc->regs_res, reg, 4, BUS_SPACE_BARRIER_WRITE);
157 }
158 
159 static __inline uint32_t
160 reg_read(ig4iic_softc_t *sc, uint32_t reg)
161 {
162 	uint32_t value;
163 
164 	bus_barrier(sc->regs_res, reg, 4, BUS_SPACE_BARRIER_READ);
165 	value = bus_read_4(sc->regs_res, reg);
166 	return (value);
167 }
168 
169 static void
170 ig4iic_set_intr_mask(ig4iic_softc_t *sc, uint32_t val)
171 {
172 	if (sc->intr_mask != val) {
173 		reg_write(sc, IG4_REG_INTR_MASK, val);
174 		sc->intr_mask = val;
175 	}
176 }
177 
178 static int
179 intrstat2iic(ig4iic_softc_t *sc, uint32_t val)
180 {
181 	uint32_t src;
182 
183 	if (val & IG4_INTR_RX_UNDER)
184 		reg_read(sc, IG4_REG_CLR_RX_UNDER);
185 	if (val & IG4_INTR_RX_OVER)
186 		reg_read(sc, IG4_REG_CLR_RX_OVER);
187 	if (val & IG4_INTR_TX_OVER)
188 		reg_read(sc, IG4_REG_CLR_TX_OVER);
189 
190 	if (val & IG4_INTR_TX_ABRT) {
191 		src = reg_read(sc, IG4_REG_TX_ABRT_SOURCE);
192 		reg_read(sc, IG4_REG_CLR_TX_ABORT);
193 		/* User-requested abort. Not really a error */
194 		if (src & IG4_ABRTSRC_TRANSFER)
195 			return (IIC_ESTATUS);
196 		/* Master has lost arbitration */
197 		if (src & IG4_ABRTSRC_ARBLOST)
198 			return (IIC_EBUSBSY);
199 		/* Did not receive an acknowledge from the remote slave */
200 		if (src & (IG4_ABRTSRC_TXNOACK_ADDR7 |
201 			   IG4_ABRTSRC_TXNOACK_ADDR10_1 |
202 			   IG4_ABRTSRC_TXNOACK_ADDR10_2 |
203 			   IG4_ABRTSRC_TXNOACK_DATA |
204 			   IG4_ABRTSRC_GENCALL_NOACK))
205 			return (IIC_ENOACK);
206 		/* Programming errors */
207 		if (src & (IG4_ABRTSRC_GENCALL_READ |
208 			   IG4_ABRTSRC_NORESTART_START |
209 			   IG4_ABRTSRC_NORESTART_10))
210 			return (IIC_ENOTSUPP);
211 		/* Other errors */
212 		if (src & IG4_ABRTSRC_ACKED_START)
213 			return (IIC_EBUSERR);
214 	}
215 	/*
216 	 * TX_OVER, RX_OVER and RX_UNDER are caused by wrong RX/TX FIFO depth
217 	 * detection or driver's read/write pipelining errors.
218 	 */
219 	if (val & (IG4_INTR_TX_OVER | IG4_INTR_RX_OVER))
220 		return (IIC_EOVERFLOW);
221 	if (val & IG4_INTR_RX_UNDER)
222 		return (IIC_EUNDERFLOW);
223 
224 	return (IIC_NOERR);
225 }
226 
227 /*
228  * Enable or disable the controller and wait for the controller to acknowledge
229  * the state change.
230  */
231 static int
232 set_controller(ig4iic_softc_t *sc, uint32_t ctl)
233 {
234 	int retry;
235 	int error;
236 	uint32_t v;
237 
238 	/*
239 	 * When the controller is enabled, interrupt on STOP detect
240 	 * or receive character ready and clear pending interrupts.
241 	 */
242 	ig4iic_set_intr_mask(sc, 0);
243 	if (ctl & IG4_I2C_ENABLE)
244 		reg_read(sc, IG4_REG_CLR_INTR);
245 
246 	reg_write(sc, IG4_REG_I2C_EN, ctl);
247 	error = IIC_ETIMEOUT;
248 
249 	for (retry = 100; retry > 0; --retry) {
250 		v = reg_read(sc, IG4_REG_ENABLE_STATUS);
251 		if (((v ^ ctl) & IG4_I2C_ENABLE) == 0) {
252 			error = 0;
253 			break;
254 		}
255 		pause("i2cslv", 1);
256 	}
257 	return (error);
258 }
259 
260 /*
261  * Wait up to 25ms for the requested interrupt using a 25uS polling loop.
262  */
263 static int
264 wait_intr(ig4iic_softc_t *sc, uint32_t intr)
265 {
266 	uint32_t v;
267 	int error;
268 	int txlvl = -1;
269 	u_int count_us = 0;
270 	u_int limit_us = 25000; /* 25ms */
271 
272 	for (;;) {
273 		/*
274 		 * Check requested status
275 		 */
276 		v = reg_read(sc, IG4_REG_RAW_INTR_STAT);
277 		error = intrstat2iic(sc, v & IG4_INTR_ERR_MASK);
278 		if (error || (v & intr))
279 			break;
280 
281 		/*
282 		 * When waiting for the transmit FIFO to become empty,
283 		 * reset the timeout if we see a change in the transmit
284 		 * FIFO level as progress is being made.
285 		 */
286 		if (intr & (IG4_INTR_TX_EMPTY | IG4_INTR_STOP_DET)) {
287 			v = reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK;
288 			if (txlvl != v) {
289 				txlvl = v;
290 				count_us = 0;
291 			}
292 		}
293 
294 		/*
295 		 * Stop if we've run out of time.
296 		 */
297 		if (count_us >= limit_us) {
298 			error = IIC_ETIMEOUT;
299 			break;
300 		}
301 
302 		/*
303 		 * When polling is not requested let the interrupt do its work.
304 		 */
305 		if (!DO_POLL(sc)) {
306 			mtx_lock_spin(&sc->io_lock);
307 			ig4iic_set_intr_mask(sc, intr | IG4_INTR_ERR_MASK);
308 			msleep_spin(sc, &sc->io_lock, "i2cwait",
309 				  (hz + 99) / 100); /* sleep up to 10ms */
310 			ig4iic_set_intr_mask(sc, 0);
311 			mtx_unlock_spin(&sc->io_lock);
312 			count_us += 10000;
313 		} else {
314 			DELAY(25);
315 			count_us += 25;
316 		}
317 	}
318 
319 	return (error);
320 }
321 
322 /*
323  * Set the slave address.  The controller must be disabled when
324  * changing the address.
325  *
326  * This operation does not issue anything to the I2C bus but sets
327  * the target address for when the controller later issues a START.
328  */
329 static void
330 set_slave_addr(ig4iic_softc_t *sc, uint8_t slave)
331 {
332 	uint32_t tar;
333 	uint32_t ctl;
334 	int use_10bit;
335 
336 	use_10bit = 0;
337 	if (sc->slave_valid && sc->last_slave == slave &&
338 	    sc->use_10bit == use_10bit) {
339 		return;
340 	}
341 	sc->use_10bit = use_10bit;
342 
343 	/*
344 	 * Wait for TXFIFO to drain before disabling the controller.
345 	 */
346 	wait_intr(sc, IG4_INTR_TX_EMPTY);
347 
348 	set_controller(sc, 0);
349 	ctl = reg_read(sc, IG4_REG_CTL);
350 	ctl &= ~IG4_CTL_10BIT;
351 	ctl |= IG4_CTL_RESTARTEN;
352 
353 	tar = slave;
354 	if (sc->use_10bit) {
355 		tar |= IG4_TAR_10BIT;
356 		ctl |= IG4_CTL_10BIT;
357 	}
358 	reg_write(sc, IG4_REG_CTL, ctl);
359 	reg_write(sc, IG4_REG_TAR_ADD, tar);
360 	set_controller(sc, IG4_I2C_ENABLE);
361 	sc->slave_valid = 1;
362 	sc->last_slave = slave;
363 }
364 
365 /*
366  *				IICBUS API FUNCTIONS
367  */
368 static int
369 ig4iic_xfer_start(ig4iic_softc_t *sc, uint16_t slave, bool repeated_start)
370 {
371 	set_slave_addr(sc, slave >> 1);
372 
373 	if (!repeated_start) {
374 		/*
375 		 * Clear any previous TX/RX FIFOs overflow/underflow bits
376 		 * and I2C bus STOP condition.
377 		 */
378 		reg_read(sc, IG4_REG_CLR_INTR);
379 	}
380 
381 	return (0);
382 }
383 
384 static bool
385 ig4iic_xfer_is_started(ig4iic_softc_t *sc)
386 {
387 	/*
388 	 * It requires that no IG4_REG_CLR_INTR or IG4_REG_CLR_START/STOP_DET
389 	 * register reads is issued after START condition.
390 	 */
391 	return ((reg_read(sc, IG4_REG_RAW_INTR_STAT) &
392 	    (IG4_INTR_START_DET | IG4_INTR_STOP_DET)) == IG4_INTR_START_DET);
393 }
394 
395 static int
396 ig4iic_xfer_abort(ig4iic_softc_t *sc)
397 {
398 	int error;
399 
400 	/* Request send of STOP condition and flush of TX FIFO */
401 	set_controller(sc, IG4_I2C_ABORT | IG4_I2C_ENABLE);
402 	/*
403 	 * Wait for the TX_ABRT interrupt with ABRTSRC_TRANSFER
404 	 * bit set in TX_ABRT_SOURCE register.
405 	 */
406 	error = wait_intr(sc, IG4_INTR_STOP_DET);
407 	set_controller(sc, IG4_I2C_ENABLE);
408 
409 	return (error == IIC_ESTATUS ? 0 : error);
410 }
411 
412 /*
413  * Amount of unread data before next burst to get better I2C bus utilization.
414  * 2 bytes is enough in FAST mode. 8 bytes is better in FAST+ and HIGH modes.
415  * Intel-recommended value is 16 for DMA transfers with 64-byte depth FIFOs.
416  */
417 #define	IG4_FIFO_LOWAT	2
418 
419 static int
420 ig4iic_read(ig4iic_softc_t *sc, uint8_t *buf, uint16_t len,
421     bool repeated_start, bool stop)
422 {
423 	uint32_t cmd;
424 	int requested = 0;
425 	int received = 0;
426 	int burst, target, lowat = 0;
427 	int error;
428 
429 	if (len == 0)
430 		return (0);
431 
432 	while (received < len) {
433 		burst = sc->cfg.txfifo_depth -
434 		    (reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
435 		if (burst <= 0) {
436 			error = wait_intr(sc, IG4_INTR_TX_EMPTY);
437 			if (error)
438 				break;
439 			burst = sc->cfg.txfifo_depth;
440 		}
441 		/* Ensure we have enough free space in RXFIFO */
442 		burst = MIN(burst, sc->cfg.rxfifo_depth - lowat);
443 		target = MIN(requested + burst, (int)len);
444 		while (requested < target) {
445 			cmd = IG4_DATA_COMMAND_RD;
446 			if (repeated_start && requested == 0)
447 				cmd |= IG4_DATA_RESTART;
448 			if (stop && requested == len - 1)
449 				cmd |= IG4_DATA_STOP;
450 			reg_write(sc, IG4_REG_DATA_CMD, cmd);
451 			requested++;
452 		}
453 		/* Leave some data queued to maintain the hardware pipeline */
454 		lowat = 0;
455 		if (requested != len && requested - received > IG4_FIFO_LOWAT)
456 			lowat = IG4_FIFO_LOWAT;
457 		/* After TXFLR fills up, clear it by reading available data */
458 		while (received < requested - lowat) {
459 			burst = MIN((int)len - received,
460 			    reg_read(sc, IG4_REG_RXFLR) & IG4_FIFOLVL_MASK);
461 			if (burst > 0) {
462 				while (burst--)
463 					buf[received++] = 0xFF &
464 					    reg_read(sc, IG4_REG_DATA_CMD);
465 			} else {
466 				error = wait_intr(sc, IG4_INTR_RX_FULL);
467 				if (error)
468 					goto out;
469 			}
470 		}
471 	}
472 out:
473 	return (error);
474 }
475 
476 static int
477 ig4iic_write(ig4iic_softc_t *sc, uint8_t *buf, uint16_t len,
478     bool repeated_start, bool stop)
479 {
480 	uint32_t cmd;
481 	int sent = 0;
482 	int burst, target;
483 	int error;
484 	bool lowat_set = false;
485 
486 	if (len == 0)
487 		return (0);
488 
489 	while (sent < len) {
490 		burst = sc->cfg.txfifo_depth -
491 		    (reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
492 		target = MIN(sent + burst, (int)len);
493 		/* Leave some data queued to maintain the hardware pipeline */
494 		if (!lowat_set && target != len) {
495 			lowat_set = true;
496 			reg_write(sc, IG4_REG_TX_TL, IG4_FIFO_LOWAT);
497 		}
498 		while(sent < target) {
499 			cmd = buf[sent];
500 			if (repeated_start && sent == 0)
501 				cmd |= IG4_DATA_RESTART;
502 			if (stop && sent == len - 1)
503 				cmd |= IG4_DATA_STOP;
504 			reg_write(sc, IG4_REG_DATA_CMD, cmd);
505 			sent++;
506 		}
507 		if (sent < len) {
508 			error = wait_intr(sc, IG4_INTR_TX_EMPTY);
509 			if (error)
510 				break;
511 		}
512 	}
513 	if (lowat_set)
514 		reg_write(sc, IG4_REG_TX_TL, 0);
515 
516 	return (error);
517 }
518 
519 int
520 ig4iic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
521 {
522 	ig4iic_softc_t *sc = device_get_softc(dev);
523 	const char *reason = NULL;
524 	uint32_t i;
525 	int error;
526 	int unit;
527 	bool rpstart;
528 	bool stop;
529 	bool allocated;
530 
531 	/*
532 	 * The hardware interface imposes limits on allowed I2C messages.
533 	 * It is not possible to explicitly send a start or stop.
534 	 * They are automatically sent (or not sent, depending on the
535 	 * configuration) when a data byte is transferred.
536 	 * For this reason it's impossible to send a message with no data
537 	 * at all (like an SMBus quick message).
538 	 * The start condition is automatically generated after the stop
539 	 * condition, so it's impossible to not have a start after a stop.
540 	 * The repeated start condition is automatically sent if a change
541 	 * of the transfer direction happens, so it's impossible to have
542 	 * a change of direction without a (repeated) start.
543 	 * The repeated start can be forced even without the change of
544 	 * direction.
545 	 * Changing the target slave address requires resetting the hardware
546 	 * state, so it's impossible to do that without the stop followed
547 	 * by the start.
548 	 */
549 	for (i = 0; i < nmsgs; i++) {
550 #if 0
551 		if (i == 0 && (msgs[i].flags & IIC_M_NOSTART) != 0) {
552 			reason = "first message without start";
553 			break;
554 		}
555 		if (i == nmsgs - 1 && (msgs[i].flags & IIC_M_NOSTOP) != 0) {
556 			reason = "last message without stop";
557 			break;
558 		}
559 #endif
560 		if (msgs[i].len == 0) {
561 			reason = "message with no data";
562 			break;
563 		}
564 		if (i > 0) {
565 			if ((msgs[i].flags & IIC_M_NOSTART) != 0 &&
566 			    (msgs[i - 1].flags & IIC_M_NOSTOP) == 0) {
567 				reason = "stop not followed by start";
568 				break;
569 			}
570 			if ((msgs[i - 1].flags & IIC_M_NOSTOP) != 0 &&
571 			    msgs[i].slave != msgs[i - 1].slave) {
572 				reason = "change of slave without stop";
573 				break;
574 			}
575 			if ((msgs[i].flags & IIC_M_NOSTART) != 0 &&
576 			    (msgs[i].flags & IIC_M_RD) !=
577 			    (msgs[i - 1].flags & IIC_M_RD)) {
578 				reason = "change of direction without repeated"
579 				    " start";
580 				break;
581 			}
582 		}
583 	}
584 	if (reason != NULL) {
585 		if (bootverbose)
586 			device_printf(dev, "%s\n", reason);
587 		return (IIC_ENOTSUPP);
588 	}
589 
590 	/* Check if device is already allocated with iicbus_request_bus() */
591 	allocated = sx_xlocked(&sc->call_lock) != 0;
592 	if (!allocated)
593 		sx_xlock(&sc->call_lock);
594 
595 	/* Debugging - dump registers. */
596 	if (ig4_dump) {
597 		unit = device_get_unit(dev);
598 		if (ig4_dump & (1 << unit)) {
599 			ig4_dump &= ~(1 << unit);
600 			ig4iic_dump(sc);
601 		}
602 	}
603 
604 	/*
605 	 * Clear any previous abort condition that may have been holding
606 	 * the txfifo in reset.
607 	 */
608 	reg_read(sc, IG4_REG_CLR_TX_ABORT);
609 
610 	rpstart = false;
611 	error = 0;
612 	for (i = 0; i < nmsgs; i++) {
613 		if ((msgs[i].flags & IIC_M_NOSTART) == 0) {
614 			error = ig4iic_xfer_start(sc, msgs[i].slave, rpstart);
615 		} else {
616 			if (!sc->slave_valid ||
617 			    (msgs[i].slave >> 1) != sc->last_slave) {
618 				device_printf(dev, "start condition suppressed"
619 				    "but slave address is not set up");
620 				error = EINVAL;
621 				break;
622 			}
623 			rpstart = false;
624 		}
625 		if (error != 0)
626 			break;
627 
628 		stop = (msgs[i].flags & IIC_M_NOSTOP) == 0;
629 		if (msgs[i].flags & IIC_M_RD)
630 			error = ig4iic_read(sc, msgs[i].buf, msgs[i].len,
631 			    rpstart, stop);
632 		else
633 			error = ig4iic_write(sc, msgs[i].buf, msgs[i].len,
634 			    rpstart, stop);
635 
636 		/* Wait for error or stop condition occurred on the I2C bus */
637 		if (stop && error == 0) {
638 			error = wait_intr(sc, IG4_INTR_STOP_DET);
639 			if (error == 0)
640 				reg_read(sc, IG4_REG_CLR_INTR);
641 		}
642 
643 		if (error != 0) {
644 			/*
645 			 * Send STOP condition if it's not done yet and flush
646 			 * both FIFOs. Do a controller soft reset if transfer
647 			 * abort is failed.
648 			 */
649 			if (ig4iic_xfer_is_started(sc) &&
650 			    ig4iic_xfer_abort(sc) != 0) {
651 				device_printf(sc->dev, "Failed to abort "
652 				    "transfer. Do the controller reset.\n");
653 				ig4iic_set_config(sc, true);
654 			} else {
655 				while (reg_read(sc, IG4_REG_I2C_STA) &
656 				    IG4_STATUS_RX_NOTEMPTY)
657 					reg_read(sc, IG4_REG_DATA_CMD);
658 				reg_read(sc, IG4_REG_TX_ABRT_SOURCE);
659 				reg_read(sc, IG4_REG_CLR_INTR);
660 			}
661 			break;
662 		}
663 
664 		rpstart = !stop;
665 	}
666 
667 	if (!allocated)
668 		sx_unlock(&sc->call_lock);
669 	return (error);
670 }
671 
672 int
673 ig4iic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
674 {
675 	ig4iic_softc_t *sc = device_get_softc(dev);
676 	bool allocated;
677 
678 	allocated = sx_xlocked(&sc->call_lock) != 0;
679 	if (!allocated)
680 		sx_xlock(&sc->call_lock);
681 
682 	/* TODO handle speed configuration? */
683 	if (oldaddr != NULL)
684 		*oldaddr = sc->last_slave << 1;
685 	set_slave_addr(sc, addr >> 1);
686 	if (addr == IIC_UNKNOWN)
687 		sc->slave_valid = false;
688 
689 	if (!allocated)
690 		sx_unlock(&sc->call_lock);
691 	return (0);
692 }
693 
694 int
695 ig4iic_callback(device_t dev, int index, caddr_t data)
696 {
697 	ig4iic_softc_t *sc = device_get_softc(dev);
698 	int error = 0;
699 	int how;
700 
701 	switch (index) {
702 	case IIC_REQUEST_BUS:
703 		/* force polling if ig4iic is requested with IIC_DONTWAIT */
704 		how = *(int *)data;
705 		if ((how & IIC_WAIT) == 0) {
706 			if (sx_try_xlock(&sc->call_lock) == 0)
707 				error = IIC_EBUSBSY;
708 			else
709 				sc->poll = true;
710 		} else
711 			sx_xlock(&sc->call_lock);
712 		break;
713 
714 	case IIC_RELEASE_BUS:
715 		sc->poll = false;
716 		sx_unlock(&sc->call_lock);
717 		break;
718 
719 	default:
720 		error = errno2iic(EINVAL);
721 	}
722 
723 	return (error);
724 }
725 
726 /*
727  * Clock register values can be calculated with following rough equations:
728  * SCL_HCNT = ceil(IC clock rate * tHIGH)
729  * SCL_LCNT = ceil(IC clock rate * tLOW)
730  * SDA_HOLD = ceil(IC clock rate * SDA hold time)
731  * Precise equations take signal's falling, rising and spike suppression
732  * times in to account. They can be found in Synopsys or Intel documentation.
733  *
734  * Here we snarf formulas and defaults from Linux driver to be able to use
735  * timing values provided by Intel LPSS driver "as is".
736  */
737 static int
738 ig4iic_clk_params(const struct ig4_hw *hw, int speed,
739     uint16_t *scl_hcnt, uint16_t *scl_lcnt, uint16_t *sda_hold)
740 {
741 	uint32_t thigh, tlow, tf_max;	/* nsec */
742 	uint32_t sda_fall_time;		/* nsec */
743         uint32_t scl_fall_time;		/* nsec */
744 
745 	switch (speed) {
746 	case IG4_CTL_SPEED_STD:
747 		thigh = IG4_SPEED_STD_THIGH;
748 		tlow = IG4_SPEED_STD_TLOW;
749 		tf_max = IG4_SPEED_STD_TF_MAX;
750 		break;
751 
752 	case IG4_CTL_SPEED_FAST:
753 		thigh = IG4_SPEED_FAST_THIGH;
754 		tlow = IG4_SPEED_FAST_TLOW;
755 		tf_max = IG4_SPEED_FAST_TF_MAX;
756 		break;
757 
758 	default:
759 		return (EINVAL);
760 	}
761 
762 	/* Use slowest falling time defaults to be on the safe side */
763 	sda_fall_time = hw->sda_fall_time == 0 ? tf_max : hw->sda_fall_time;
764 	*scl_hcnt = (uint16_t)
765 	    ((hw->ic_clock_rate * (thigh + sda_fall_time) + 500) / 1000 - 3);
766 
767 	scl_fall_time = hw->scl_fall_time == 0 ? tf_max : hw->scl_fall_time;
768 	*scl_lcnt = (uint16_t)
769 	    ((hw->ic_clock_rate * (tlow + scl_fall_time) + 500) / 1000 - 1);
770 
771 	/*
772 	 * There is no "known good" default value for tHD;DAT so keep SDA_HOLD
773 	 * intact if sda_hold_time value is not provided.
774 	 */
775 	if (hw->sda_hold_time != 0)
776 		*sda_hold = (uint16_t)
777 		    ((hw->ic_clock_rate * hw->sda_hold_time + 500) / 1000);
778 
779 	return (0);
780 }
781 
782 #ifdef DEV_ACPI
783 static ACPI_STATUS
784 ig4iic_acpi_params(ACPI_HANDLE handle, char *method,
785     uint16_t *scl_hcnt, uint16_t *scl_lcnt, uint16_t *sda_hold)
786 {
787 	ACPI_BUFFER buf;
788 	ACPI_OBJECT *obj, *elems;
789 	ACPI_STATUS status;
790 
791 	buf.Pointer = NULL;
792 	buf.Length = ACPI_ALLOCATE_BUFFER;
793 
794 	status = AcpiEvaluateObject(handle, method, NULL, &buf);
795 	if (ACPI_FAILURE(status))
796 		return (status);
797 
798 	status = AE_TYPE;
799 	obj = (ACPI_OBJECT *)buf.Pointer;
800 	if (obj->Type == ACPI_TYPE_PACKAGE && obj->Package.Count == 3) {
801 		elems = obj->Package.Elements;
802 		*scl_hcnt = elems[0].Integer.Value & IG4_SCL_CLOCK_MASK;
803 		*scl_lcnt = elems[1].Integer.Value & IG4_SCL_CLOCK_MASK;
804 		*sda_hold = elems[2].Integer.Value & IG4_SDA_TX_HOLD_MASK;
805 		status = AE_OK;
806 	}
807 
808 	AcpiOsFree(obj);
809 
810 	return (status);
811 }
812 #endif /* DEV_ACPI */
813 
814 static void
815 ig4iic_get_config(ig4iic_softc_t *sc)
816 {
817 	const struct ig4_hw *hw;
818 	uint32_t v;
819 #ifdef DEV_ACPI
820 	ACPI_HANDLE handle;
821 #endif
822 	/* Fetch default hardware config from controller */
823 	sc->cfg.version = reg_read(sc, IG4_REG_COMP_VER);
824 	sc->cfg.bus_speed = reg_read(sc, IG4_REG_CTL) & IG4_CTL_SPEED_MASK;
825 	sc->cfg.ss_scl_hcnt =
826 	    reg_read(sc, IG4_REG_SS_SCL_HCNT) & IG4_SCL_CLOCK_MASK;
827 	sc->cfg.ss_scl_lcnt =
828 	    reg_read(sc, IG4_REG_SS_SCL_LCNT) & IG4_SCL_CLOCK_MASK;
829 	sc->cfg.fs_scl_hcnt =
830 	    reg_read(sc, IG4_REG_FS_SCL_HCNT) & IG4_SCL_CLOCK_MASK;
831 	sc->cfg.fs_scl_lcnt =
832 	    reg_read(sc, IG4_REG_FS_SCL_LCNT) & IG4_SCL_CLOCK_MASK;
833 	sc->cfg.ss_sda_hold = sc->cfg.fs_sda_hold =
834 	    reg_read(sc, IG4_REG_SDA_HOLD) & IG4_SDA_TX_HOLD_MASK;
835 
836 	if (sc->cfg.bus_speed != IG4_CTL_SPEED_STD)
837 		sc->cfg.bus_speed = IG4_CTL_SPEED_FAST;
838 
839 	/* REG_COMP_PARAM1 is not documented in latest Intel specs */
840 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
841 		v = reg_read(sc, IG4_REG_COMP_PARAM1);
842 		if (IG4_PARAM1_TXFIFO_DEPTH(v) != 0)
843 			sc->cfg.txfifo_depth = IG4_PARAM1_TXFIFO_DEPTH(v);
844 		if (IG4_PARAM1_RXFIFO_DEPTH(v) != 0)
845 			sc->cfg.rxfifo_depth = IG4_PARAM1_RXFIFO_DEPTH(v);
846 	} else {
847 		/*
848 		 * Hardware does not allow FIFO Threshold Levels value to be
849 		 * set larger than the depth of the buffer. If an attempt is
850 		 * made to do that, the actual value set will be the maximum
851 		 * depth of the buffer.
852 		 */
853 		v = reg_read(sc, IG4_REG_TX_TL);
854 		reg_write(sc, IG4_REG_TX_TL, v | IG4_FIFO_MASK);
855 		sc->cfg.txfifo_depth =
856 		    (reg_read(sc, IG4_REG_TX_TL) & IG4_FIFO_MASK) + 1;
857 		reg_write(sc, IG4_REG_TX_TL, v);
858 		v = reg_read(sc, IG4_REG_RX_TL);
859 		reg_write(sc, IG4_REG_RX_TL, v | IG4_FIFO_MASK);
860 		sc->cfg.rxfifo_depth =
861 		    (reg_read(sc, IG4_REG_RX_TL) & IG4_FIFO_MASK) + 1;
862 		reg_write(sc, IG4_REG_RX_TL, v);
863 	}
864 
865 	/* Override hardware config with IC_clock-based counter values */
866 	if (ig4_timings < 2 && sc->version < nitems(ig4iic_hw)) {
867 		hw = &ig4iic_hw[sc->version];
868 		sc->cfg.bus_speed = IG4_CTL_SPEED_FAST;
869 		ig4iic_clk_params(hw, IG4_CTL_SPEED_STD, &sc->cfg.ss_scl_hcnt,
870 		    &sc->cfg.ss_scl_lcnt, &sc->cfg.ss_sda_hold);
871 		ig4iic_clk_params(hw, IG4_CTL_SPEED_FAST, &sc->cfg.fs_scl_hcnt,
872 		    &sc->cfg.fs_scl_lcnt, &sc->cfg.fs_sda_hold);
873 		if (hw->txfifo_depth != 0)
874 			sc->cfg.txfifo_depth = hw->txfifo_depth;
875 		if (hw->rxfifo_depth != 0)
876 			sc->cfg.rxfifo_depth = hw->rxfifo_depth;
877 	} else if (ig4_timings == 2) {
878 		/*
879 		 * Timings of original ig4 driver:
880 		 * Program based on a 25000 Hz clock.  This is a bit of a
881 		 * hack (obviously).  The defaults are 400 and 470 for standard
882 		 * and 60 and 130 for fast.  The defaults for standard fail
883 		 * utterly (presumably cause an abort) because the clock time
884 		 * is ~18.8ms by default.  This brings it down to ~4ms.
885 		 */
886 		sc->cfg.bus_speed = IG4_CTL_SPEED_STD;
887 		sc->cfg.ss_scl_hcnt = sc->cfg.fs_scl_hcnt = 100;
888 		sc->cfg.ss_scl_lcnt = sc->cfg.fs_scl_lcnt = 125;
889 		if (sc->version == IG4_SKYLAKE)
890 			sc->cfg.ss_sda_hold = sc->cfg.fs_sda_hold = 28;
891 	}
892 
893 #ifdef DEV_ACPI
894 	/* Evaluate SSCN and FMCN ACPI methods to fetch timings */
895 	if (ig4_timings == 0 && (handle = acpi_get_handle(sc->dev)) != NULL) {
896 		ig4iic_acpi_params(handle, "SSCN", &sc->cfg.ss_scl_hcnt,
897 		    &sc->cfg.ss_scl_lcnt, &sc->cfg.ss_sda_hold);
898 		ig4iic_acpi_params(handle, "FMCN", &sc->cfg.fs_scl_hcnt,
899 		    &sc->cfg.fs_scl_lcnt, &sc->cfg.fs_sda_hold);
900 	}
901 #endif
902 
903 	if (bootverbose) {
904 		device_printf(sc->dev, "Controller parameters:\n");
905 		printf("  Speed: %s\n",
906 		    sc->cfg.bus_speed == IG4_CTL_SPEED_STD ? "Std" : "Fast");
907 		printf("  Regs:  HCNT  :LCNT  :SDAHLD\n");
908 		printf("  Std:   0x%04hx:0x%04hx:0x%04hx\n",
909 		    sc->cfg.ss_scl_hcnt, sc->cfg.ss_scl_lcnt,
910 		    sc->cfg.ss_sda_hold);
911 		printf("  Fast:  0x%04hx:0x%04hx:0x%04hx\n",
912 		    sc->cfg.fs_scl_hcnt, sc->cfg.fs_scl_lcnt,
913 		    sc->cfg.fs_sda_hold);
914 		printf("  FIFO:  RX:0x%04x: TX:0x%04x\n",
915 		    sc->cfg.rxfifo_depth, sc->cfg.txfifo_depth);
916 	}
917 }
918 
919 static int
920 ig4iic_set_config(ig4iic_softc_t *sc, bool reset)
921 {
922 	uint32_t v;
923 
924 	v = reg_read(sc, IG4_REG_DEVIDLE_CTRL);
925 	if (IG4_HAS_ADDREGS(sc->version) && (v & IG4_RESTORE_REQUIRED)) {
926 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, IG4_DEVICE_IDLE | IG4_RESTORE_REQUIRED);
927 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, 0);
928 		pause("i2crst", 1);
929 		reset = true;
930 	}
931 
932 	if ((sc->version == IG4_HASWELL || sc->version == IG4_ATOM) && reset) {
933 		reg_write(sc, IG4_REG_RESETS_HSW, IG4_RESETS_ASSERT_HSW);
934 		reg_write(sc, IG4_REG_RESETS_HSW, IG4_RESETS_DEASSERT_HSW);
935 	} else if (IG4_HAS_ADDREGS(sc->version) && reset) {
936 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_ASSERT_SKL);
937 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_DEASSERT_SKL);
938 	}
939 
940 	if (sc->version == IG4_ATOM)
941 		v = reg_read(sc, IG4_REG_COMP_TYPE);
942 
943 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
944 		v = reg_read(sc, IG4_REG_COMP_PARAM1);
945 		v = reg_read(sc, IG4_REG_GENERAL);
946 		/*
947 		 * The content of IG4_REG_GENERAL is different for each
948 		 * controller version.
949 		 */
950 		if (sc->version == IG4_HASWELL &&
951 		    (v & IG4_GENERAL_SWMODE) == 0) {
952 			v |= IG4_GENERAL_SWMODE;
953 			reg_write(sc, IG4_REG_GENERAL, v);
954 			v = reg_read(sc, IG4_REG_GENERAL);
955 		}
956 	}
957 
958 	if (sc->version == IG4_HASWELL) {
959 		v = reg_read(sc, IG4_REG_SW_LTR_VALUE);
960 		v = reg_read(sc, IG4_REG_AUTO_LTR_VALUE);
961 	} else if (IG4_HAS_ADDREGS(sc->version)) {
962 		v = reg_read(sc, IG4_REG_ACTIVE_LTR_VALUE);
963 		v = reg_read(sc, IG4_REG_IDLE_LTR_VALUE);
964 	}
965 
966 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
967 		v = reg_read(sc, IG4_REG_COMP_VER);
968 		if (v < IG4_COMP_MIN_VER)
969 			return(ENXIO);
970 	}
971 
972 	if (set_controller(sc, 0)) {
973 		device_printf(sc->dev, "controller error during attach-1\n");
974 		return (ENXIO);
975 	}
976 
977 	reg_read(sc, IG4_REG_CLR_INTR);
978 	reg_write(sc, IG4_REG_INTR_MASK, 0);
979 	sc->intr_mask = 0;
980 
981 	reg_write(sc, IG4_REG_SS_SCL_HCNT, sc->cfg.ss_scl_hcnt);
982 	reg_write(sc, IG4_REG_SS_SCL_LCNT, sc->cfg.ss_scl_lcnt);
983 	reg_write(sc, IG4_REG_FS_SCL_HCNT, sc->cfg.fs_scl_hcnt);
984 	reg_write(sc, IG4_REG_FS_SCL_LCNT, sc->cfg.fs_scl_lcnt);
985 	reg_write(sc, IG4_REG_SDA_HOLD,
986 	    (sc->cfg.bus_speed  & IG4_CTL_SPEED_MASK) == IG4_CTL_SPEED_STD ?
987 	      sc->cfg.ss_sda_hold : sc->cfg.fs_sda_hold);
988 
989 	/*
990 	 * Use a threshold of 1 so we get interrupted on each character,
991 	 * allowing us to use mtx_sleep() in our poll code.  Not perfect
992 	 * but this is better than using DELAY() for receiving data.
993 	 *
994 	 * See ig4_var.h for details on interrupt handler synchronization.
995 	 */
996 	reg_write(sc, IG4_REG_RX_TL, 0);
997 	reg_write(sc, IG4_REG_TX_TL, 0);
998 
999 	reg_write(sc, IG4_REG_CTL,
1000 		  IG4_CTL_MASTER |
1001 		  IG4_CTL_SLAVE_DISABLE |
1002 		  IG4_CTL_RESTARTEN |
1003 		  (sc->cfg.bus_speed & IG4_CTL_SPEED_MASK));
1004 
1005 	/* Force setting of the target address on the next transfer */
1006 	sc->slave_valid = 0;
1007 
1008 	return (0);
1009 }
1010 
1011 /*
1012  * Called from ig4iic_pci_attach/detach()
1013  */
1014 int
1015 ig4iic_attach(ig4iic_softc_t *sc)
1016 {
1017 	int error;
1018 
1019 	mtx_init(&sc->io_lock, "IG4 I/O lock", NULL, MTX_SPIN);
1020 	sx_init(&sc->call_lock, "IG4 call lock");
1021 
1022 	ig4iic_get_config(sc);
1023 
1024 	error = ig4iic_set_config(sc, IG4_HAS_ADDREGS(sc->version));
1025 	if (error)
1026 		goto done;
1027 
1028 	sc->iicbus = device_add_child(sc->dev, "iicbus", -1);
1029 	if (sc->iicbus == NULL) {
1030 		device_printf(sc->dev, "iicbus driver not found\n");
1031 		error = ENXIO;
1032 		goto done;
1033 	}
1034 
1035 	if (set_controller(sc, IG4_I2C_ENABLE)) {
1036 		device_printf(sc->dev, "controller error during attach-2\n");
1037 		error = ENXIO;
1038 		goto done;
1039 	}
1040 	if (set_controller(sc, 0)) {
1041 		device_printf(sc->dev, "controller error during attach-3\n");
1042 		error = ENXIO;
1043 		goto done;
1044 	}
1045 	error = bus_setup_intr(sc->dev, sc->intr_res, INTR_TYPE_MISC | INTR_MPSAFE,
1046 			       ig4iic_intr, NULL, sc, &sc->intr_handle);
1047 	if (error) {
1048 		device_printf(sc->dev,
1049 			      "Unable to setup irq: error %d\n", error);
1050 	}
1051 
1052 	error = bus_generic_attach(sc->dev);
1053 	if (error) {
1054 		device_printf(sc->dev,
1055 			      "failed to attach child: error %d\n", error);
1056 	}
1057 
1058 done:
1059 	return (error);
1060 }
1061 
1062 int
1063 ig4iic_detach(ig4iic_softc_t *sc)
1064 {
1065 	int error;
1066 
1067 	if (device_is_attached(sc->dev)) {
1068 		error = bus_generic_detach(sc->dev);
1069 		if (error)
1070 			return (error);
1071 	}
1072 	if (sc->iicbus)
1073 		device_delete_child(sc->dev, sc->iicbus);
1074 	if (sc->intr_handle)
1075 		bus_teardown_intr(sc->dev, sc->intr_res, sc->intr_handle);
1076 
1077 	sx_xlock(&sc->call_lock);
1078 
1079 	sc->iicbus = NULL;
1080 	sc->intr_handle = NULL;
1081 	reg_write(sc, IG4_REG_INTR_MASK, 0);
1082 	set_controller(sc, 0);
1083 
1084 	sx_xunlock(&sc->call_lock);
1085 
1086 	mtx_destroy(&sc->io_lock);
1087 	sx_destroy(&sc->call_lock);
1088 
1089 	return (0);
1090 }
1091 
1092 int
1093 ig4iic_suspend(ig4iic_softc_t *sc)
1094 {
1095 	int error;
1096 
1097 	/* suspend all children */
1098 	error = bus_generic_suspend(sc->dev);
1099 
1100 	sx_xlock(&sc->call_lock);
1101 	set_controller(sc, 0);
1102 	if (IG4_HAS_ADDREGS(sc->version)) {
1103 		/*
1104 		 * Place the device in the idle state, just to be safe
1105 		 */
1106 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, IG4_DEVICE_IDLE);
1107 		/*
1108 		 * Controller can become dysfunctional if I2C lines are pulled
1109 		 * down when suspend procedure turns off power to I2C device.
1110 		 * Place device in the reset state to avoid this.
1111 		 */
1112 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_ASSERT_SKL);
1113 	}
1114 	sx_xunlock(&sc->call_lock);
1115 
1116 	return (error);
1117 }
1118 
1119 int ig4iic_resume(ig4iic_softc_t *sc)
1120 {
1121 	int error;
1122 
1123 	sx_xlock(&sc->call_lock);
1124 	if (ig4iic_set_config(sc, IG4_HAS_ADDREGS(sc->version)))
1125 		device_printf(sc->dev, "controller error during resume\n");
1126 	sx_xunlock(&sc->call_lock);
1127 
1128 	error = bus_generic_resume(sc->dev);
1129 
1130 	return (error);
1131 }
1132 
1133 /*
1134  * Interrupt Operation, see ig4_var.h for locking semantics.
1135  */
1136 static int
1137 ig4iic_intr(void *cookie)
1138 {
1139 	ig4iic_softc_t *sc = cookie;
1140 	int retval = FILTER_STRAY;
1141 
1142 	mtx_lock_spin(&sc->io_lock);
1143 	/* Ignore stray interrupts */
1144 	if (sc->intr_mask != 0 && reg_read(sc, IG4_REG_INTR_STAT) != 0) {
1145 		/* Interrupt bits are cleared in wait_intr() loop */
1146 		ig4iic_set_intr_mask(sc, 0);
1147 		wakeup(sc);
1148 		retval = FILTER_HANDLED;
1149 	}
1150 	mtx_unlock_spin(&sc->io_lock);
1151 
1152 	return (retval);
1153 }
1154 
1155 #define REGDUMP(sc, reg)	\
1156 	device_printf(sc->dev, "  %-23s %08x\n", #reg, reg_read(sc, reg))
1157 
1158 static void
1159 ig4iic_dump(ig4iic_softc_t *sc)
1160 {
1161 	device_printf(sc->dev, "ig4iic register dump:\n");
1162 	REGDUMP(sc, IG4_REG_CTL);
1163 	REGDUMP(sc, IG4_REG_TAR_ADD);
1164 	REGDUMP(sc, IG4_REG_SS_SCL_HCNT);
1165 	REGDUMP(sc, IG4_REG_SS_SCL_LCNT);
1166 	REGDUMP(sc, IG4_REG_FS_SCL_HCNT);
1167 	REGDUMP(sc, IG4_REG_FS_SCL_LCNT);
1168 	REGDUMP(sc, IG4_REG_INTR_STAT);
1169 	REGDUMP(sc, IG4_REG_INTR_MASK);
1170 	REGDUMP(sc, IG4_REG_RAW_INTR_STAT);
1171 	REGDUMP(sc, IG4_REG_RX_TL);
1172 	REGDUMP(sc, IG4_REG_TX_TL);
1173 	REGDUMP(sc, IG4_REG_I2C_EN);
1174 	REGDUMP(sc, IG4_REG_I2C_STA);
1175 	REGDUMP(sc, IG4_REG_TXFLR);
1176 	REGDUMP(sc, IG4_REG_RXFLR);
1177 	REGDUMP(sc, IG4_REG_SDA_HOLD);
1178 	REGDUMP(sc, IG4_REG_TX_ABRT_SOURCE);
1179 	REGDUMP(sc, IG4_REG_SLV_DATA_NACK);
1180 	REGDUMP(sc, IG4_REG_DMA_CTRL);
1181 	REGDUMP(sc, IG4_REG_DMA_TDLR);
1182 	REGDUMP(sc, IG4_REG_DMA_RDLR);
1183 	REGDUMP(sc, IG4_REG_SDA_SETUP);
1184 	REGDUMP(sc, IG4_REG_ENABLE_STATUS);
1185 	REGDUMP(sc, IG4_REG_COMP_PARAM1);
1186 	REGDUMP(sc, IG4_REG_COMP_VER);
1187 	if (sc->version == IG4_ATOM) {
1188 		REGDUMP(sc, IG4_REG_COMP_TYPE);
1189 		REGDUMP(sc, IG4_REG_CLK_PARMS);
1190 	}
1191 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
1192 		REGDUMP(sc, IG4_REG_RESETS_HSW);
1193 		REGDUMP(sc, IG4_REG_GENERAL);
1194 	} else if (sc->version == IG4_SKYLAKE) {
1195 		REGDUMP(sc, IG4_REG_RESETS_SKL);
1196 	}
1197 	if (sc->version == IG4_HASWELL) {
1198 		REGDUMP(sc, IG4_REG_SW_LTR_VALUE);
1199 		REGDUMP(sc, IG4_REG_AUTO_LTR_VALUE);
1200 	} else if (IG4_HAS_ADDREGS(sc->version)) {
1201 		REGDUMP(sc, IG4_REG_ACTIVE_LTR_VALUE);
1202 		REGDUMP(sc, IG4_REG_IDLE_LTR_VALUE);
1203 	}
1204 }
1205 #undef REGDUMP
1206 
1207 devclass_t ig4iic_devclass;
1208 
1209 DRIVER_MODULE(iicbus, ig4iic, iicbus_driver, iicbus_devclass, NULL, NULL);
1210 #ifdef DEV_ACPI
1211 DRIVER_MODULE(acpi_iicbus, ig4iic, acpi_iicbus_driver, iicbus_devclass, NULL,
1212     NULL);
1213 #endif
1214 MODULE_DEPEND(ig4iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
1215 MODULE_VERSION(ig4iic, 1);
1216