xref: /freebsd/sys/dev/ichiic/ig4_iic.c (revision 5b56413d04e608379c9a306373554a8e4d321bc0)
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 	reg_write(sc, IG4_REG_TX_TL, 0);
354 	wait_intr(sc, IG4_INTR_TX_EMPTY);
355 
356 	set_controller(sc, 0);
357 	ctl = reg_read(sc, IG4_REG_CTL);
358 	ctl &= ~IG4_CTL_10BIT;
359 	ctl |= IG4_CTL_RESTARTEN;
360 
361 	tar = slave;
362 	if (sc->use_10bit) {
363 		tar |= IG4_TAR_10BIT;
364 		ctl |= IG4_CTL_10BIT;
365 	}
366 	reg_write(sc, IG4_REG_CTL, ctl);
367 	reg_write(sc, IG4_REG_TAR_ADD, tar);
368 	set_controller(sc, IG4_I2C_ENABLE);
369 	sc->slave_valid = true;
370 	sc->last_slave = slave;
371 }
372 
373 /*
374  *				IICBUS API FUNCTIONS
375  */
376 static int
377 ig4iic_xfer_start(ig4iic_softc_t *sc, uint16_t slave, bool repeated_start)
378 {
379 	set_slave_addr(sc, slave >> 1);
380 
381 	if (!repeated_start) {
382 		/*
383 		 * Clear any previous TX/RX FIFOs overflow/underflow bits
384 		 * and I2C bus STOP condition.
385 		 */
386 		reg_read(sc, IG4_REG_CLR_INTR);
387 	}
388 
389 	return (0);
390 }
391 
392 static bool
393 ig4iic_xfer_is_started(ig4iic_softc_t *sc)
394 {
395 	/*
396 	 * It requires that no IG4_REG_CLR_INTR or IG4_REG_CLR_START/STOP_DET
397 	 * register reads is issued after START condition.
398 	 */
399 	return ((reg_read(sc, IG4_REG_RAW_INTR_STAT) &
400 	    (IG4_INTR_START_DET | IG4_INTR_STOP_DET)) == IG4_INTR_START_DET);
401 }
402 
403 static int
404 ig4iic_xfer_abort(ig4iic_softc_t *sc)
405 {
406 	int error;
407 
408 	/* Request send of STOP condition and flush of TX FIFO */
409 	set_controller(sc, IG4_I2C_ABORT | IG4_I2C_ENABLE);
410 	/*
411 	 * Wait for the TX_ABRT interrupt with ABRTSRC_TRANSFER
412 	 * bit set in TX_ABRT_SOURCE register.
413 	 */
414 	error = wait_intr(sc, IG4_INTR_STOP_DET);
415 	set_controller(sc, IG4_I2C_ENABLE);
416 
417 	return (error == IIC_ESTATUS ? 0 : error);
418 }
419 
420 /*
421  * Amount of unread data before next burst to get better I2C bus utilization.
422  * 2 bytes is enough in FAST mode. 8 bytes is better in FAST+ and HIGH modes.
423  * Intel-recommended value is 16 for DMA transfers with 64-byte depth FIFOs.
424  */
425 #define	IG4_FIFO_LOWAT	2
426 
427 static int
428 ig4iic_read(ig4iic_softc_t *sc, uint8_t *buf, uint16_t len,
429     bool repeated_start, bool stop)
430 {
431 	uint32_t cmd;
432 	int requested = 0;
433 	int received = 0;
434 	int burst, target, lowat = 0;
435 	int error;
436 
437 	if (len == 0)
438 		return (0);
439 
440 	while (received < len) {
441 		/* Ensure we have some free space in TXFIFO */
442 		burst = sc->cfg.txfifo_depth -
443 		    (reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
444 		if (burst <= 0) {
445 			reg_write(sc, IG4_REG_TX_TL, IG4_FIFO_LOWAT);
446 			error = wait_intr(sc, IG4_INTR_TX_EMPTY);
447 			if (error)
448 				break;
449 			burst = sc->cfg.txfifo_depth -
450 			    (reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
451 		}
452 		/* Ensure we have enough free space in RXFIFO */
453 		burst = MIN(burst, sc->cfg.rxfifo_depth -
454 		    (requested - received));
455 		target = MIN(requested + burst, (int)len);
456 		while (requested < target) {
457 			cmd = IG4_DATA_COMMAND_RD;
458 			if (repeated_start && requested == 0)
459 				cmd |= IG4_DATA_RESTART;
460 			if (stop && requested == len - 1)
461 				cmd |= IG4_DATA_STOP;
462 			reg_write(sc, IG4_REG_DATA_CMD, cmd);
463 			requested++;
464 		}
465 		/* Leave some data queued to maintain the hardware pipeline */
466 		lowat = 0;
467 		if (requested != len && requested - received > IG4_FIFO_LOWAT)
468 			lowat = IG4_FIFO_LOWAT;
469 		/* After TXFLR fills up, clear it by reading available data */
470 		while (received < requested - lowat) {
471 			burst = MIN(requested - received,
472 			    reg_read(sc, IG4_REG_RXFLR) & IG4_FIFOLVL_MASK);
473 			if (burst > 0) {
474 				while (burst--)
475 					buf[received++] = 0xFF &
476 					    reg_read(sc, IG4_REG_DATA_CMD);
477 			} else {
478 				reg_write(sc, IG4_REG_RX_TL,
479 				    requested - received - lowat - 1);
480 				error = wait_intr(sc, IG4_INTR_RX_FULL);
481 				if (error)
482 					goto out;
483 			}
484 		}
485 	}
486 out:
487 	return (error);
488 }
489 
490 static int
491 ig4iic_write(ig4iic_softc_t *sc, uint8_t *buf, uint16_t len,
492     bool repeated_start, bool stop)
493 {
494 	uint32_t cmd;
495 	int sent = 0;
496 	int burst, target;
497 	int error, lowat;
498 
499 	if (len == 0)
500 		return (0);
501 
502 	while (sent < len) {
503 		burst = sc->cfg.txfifo_depth -
504 		    (reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
505 		target = MIN(sent + burst, (int)len);
506 		while (sent < target) {
507 			cmd = buf[sent];
508 			if (repeated_start && sent == 0)
509 				cmd |= IG4_DATA_RESTART;
510 			if (stop && sent == len - 1)
511 				cmd |= IG4_DATA_STOP;
512 			reg_write(sc, IG4_REG_DATA_CMD, cmd);
513 			sent++;
514 		}
515 		if (sent < len) {
516 			if (len - sent <= sc->cfg.txfifo_depth)
517 				lowat = sc->cfg.txfifo_depth - (len - sent);
518 			else
519 				lowat = IG4_FIFO_LOWAT;
520 			reg_write(sc, IG4_REG_TX_TL, lowat);
521 			error = wait_intr(sc, IG4_INTR_TX_EMPTY);
522 			if (error)
523 				break;
524 		}
525 	}
526 
527 	return (error);
528 }
529 
530 int
531 ig4iic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
532 {
533 	ig4iic_softc_t *sc = device_get_softc(dev);
534 	const char *reason = NULL;
535 	uint32_t i;
536 	int error;
537 	int unit;
538 	bool rpstart;
539 	bool stop;
540 	bool allocated;
541 
542 	/*
543 	 * The hardware interface imposes limits on allowed I2C messages.
544 	 * It is not possible to explicitly send a start or stop.
545 	 * They are automatically sent (or not sent, depending on the
546 	 * configuration) when a data byte is transferred.
547 	 * For this reason it's impossible to send a message with no data
548 	 * at all (like an SMBus quick message).
549 	 * The start condition is automatically generated after the stop
550 	 * condition, so it's impossible to not have a start after a stop.
551 	 * The repeated start condition is automatically sent if a change
552 	 * of the transfer direction happens, so it's impossible to have
553 	 * a change of direction without a (repeated) start.
554 	 * The repeated start can be forced even without the change of
555 	 * direction.
556 	 * Changing the target slave address requires resetting the hardware
557 	 * state, so it's impossible to do that without the stop followed
558 	 * by the start.
559 	 */
560 	for (i = 0; i < nmsgs; i++) {
561 #if 0
562 		if (i == 0 && (msgs[i].flags & IIC_M_NOSTART) != 0) {
563 			reason = "first message without start";
564 			break;
565 		}
566 		if (i == nmsgs - 1 && (msgs[i].flags & IIC_M_NOSTOP) != 0) {
567 			reason = "last message without stop";
568 			break;
569 		}
570 #endif
571 		if (msgs[i].len == 0) {
572 			reason = "message with no data";
573 			break;
574 		}
575 		if (i > 0) {
576 			if ((msgs[i].flags & IIC_M_NOSTART) != 0 &&
577 			    (msgs[i - 1].flags & IIC_M_NOSTOP) == 0) {
578 				reason = "stop not followed by start";
579 				break;
580 			}
581 			if ((msgs[i - 1].flags & IIC_M_NOSTOP) != 0 &&
582 			    msgs[i].slave != msgs[i - 1].slave) {
583 				reason = "change of slave without stop";
584 				break;
585 			}
586 			if ((msgs[i].flags & IIC_M_NOSTART) != 0 &&
587 			    (msgs[i].flags & IIC_M_RD) !=
588 			    (msgs[i - 1].flags & IIC_M_RD)) {
589 				reason = "change of direction without repeated"
590 				    " start";
591 				break;
592 			}
593 		}
594 	}
595 	if (reason != NULL) {
596 		if (bootverbose)
597 			device_printf(dev, "%s\n", reason);
598 		return (IIC_ENOTSUPP);
599 	}
600 
601 	/* Check if device is already allocated with iicbus_request_bus() */
602 	allocated = sx_xlocked(&sc->call_lock) != 0;
603 	if (!allocated)
604 		sx_xlock(&sc->call_lock);
605 
606 	/* Debugging - dump registers. */
607 	if (ig4_dump) {
608 		unit = device_get_unit(dev);
609 		if (ig4_dump & (1 << unit)) {
610 			ig4_dump &= ~(1 << unit);
611 			ig4iic_dump(sc);
612 		}
613 	}
614 
615 	/*
616 	 * Clear any previous abort condition that may have been holding
617 	 * the txfifo in reset.
618 	 */
619 	reg_read(sc, IG4_REG_CLR_TX_ABORT);
620 
621 	rpstart = false;
622 	error = 0;
623 	for (i = 0; i < nmsgs; i++) {
624 		if ((msgs[i].flags & IIC_M_NOSTART) == 0) {
625 			error = ig4iic_xfer_start(sc, msgs[i].slave, rpstart);
626 		} else {
627 			if (!sc->slave_valid ||
628 			    (msgs[i].slave >> 1) != sc->last_slave) {
629 				device_printf(dev, "start condition suppressed"
630 				    "but slave address is not set up");
631 				error = EINVAL;
632 				break;
633 			}
634 			rpstart = false;
635 		}
636 		if (error != 0)
637 			break;
638 
639 		stop = (msgs[i].flags & IIC_M_NOSTOP) == 0;
640 		if (msgs[i].flags & IIC_M_RD)
641 			error = ig4iic_read(sc, msgs[i].buf, msgs[i].len,
642 			    rpstart, stop);
643 		else
644 			error = ig4iic_write(sc, msgs[i].buf, msgs[i].len,
645 			    rpstart, stop);
646 
647 		/* Wait for error or stop condition occurred on the I2C bus */
648 		if (stop && error == 0) {
649 			error = wait_intr(sc, IG4_INTR_STOP_DET);
650 			if (error == 0)
651 				reg_read(sc, IG4_REG_CLR_INTR);
652 		}
653 
654 		if (error != 0) {
655 			/*
656 			 * Send STOP condition if it's not done yet and flush
657 			 * both FIFOs. Do a controller soft reset if transfer
658 			 * abort is failed.
659 			 */
660 			if (ig4iic_xfer_is_started(sc) &&
661 			    ig4iic_xfer_abort(sc) != 0) {
662 				device_printf(sc->dev, "Failed to abort "
663 				    "transfer. Do the controller reset.\n");
664 				ig4iic_set_config(sc, true);
665 			} else {
666 				while (reg_read(sc, IG4_REG_I2C_STA) &
667 				    IG4_STATUS_RX_NOTEMPTY)
668 					reg_read(sc, IG4_REG_DATA_CMD);
669 				reg_read(sc, IG4_REG_TX_ABRT_SOURCE);
670 				reg_read(sc, IG4_REG_CLR_INTR);
671 			}
672 			break;
673 		}
674 
675 		rpstart = !stop;
676 	}
677 
678 	if (error == IIC_ENOACK && bootverbose)
679 		device_printf(dev, "Warning: NACK for slave address 0x%x\n",
680 		    msgs[i].slave >> 1);
681 
682 	if (!allocated)
683 		sx_unlock(&sc->call_lock);
684 	return (error);
685 }
686 
687 int
688 ig4iic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
689 {
690 	ig4iic_softc_t *sc = device_get_softc(dev);
691 	bool allocated;
692 
693 	allocated = sx_xlocked(&sc->call_lock) != 0;
694 	if (!allocated)
695 		sx_xlock(&sc->call_lock);
696 
697 	/* TODO handle speed configuration? */
698 	if (oldaddr != NULL)
699 		*oldaddr = sc->last_slave << 1;
700 	set_slave_addr(sc, addr >> 1);
701 	if (addr == IIC_UNKNOWN)
702 		sc->slave_valid = false;
703 
704 	if (!allocated)
705 		sx_unlock(&sc->call_lock);
706 	return (0);
707 }
708 
709 int
710 ig4iic_callback(device_t dev, int index, caddr_t data)
711 {
712 	ig4iic_softc_t *sc = device_get_softc(dev);
713 	int error = 0;
714 	int how;
715 
716 	switch (index) {
717 	case IIC_REQUEST_BUS:
718 		/* force polling if ig4iic is requested with IIC_DONTWAIT */
719 		how = *(int *)data;
720 		if ((how & IIC_WAIT) == 0) {
721 			if (sx_try_xlock(&sc->call_lock) == 0)
722 				error = IIC_EBUSBSY;
723 			else
724 				sc->poll = true;
725 		} else
726 			sx_xlock(&sc->call_lock);
727 		break;
728 
729 	case IIC_RELEASE_BUS:
730 		sc->poll = false;
731 		sx_unlock(&sc->call_lock);
732 		break;
733 
734 	default:
735 		error = errno2iic(EINVAL);
736 	}
737 
738 	return (error);
739 }
740 
741 /*
742  * Clock register values can be calculated with following rough equations:
743  * SCL_HCNT = ceil(IC clock rate * tHIGH)
744  * SCL_LCNT = ceil(IC clock rate * tLOW)
745  * SDA_HOLD = ceil(IC clock rate * SDA hold time)
746  * Precise equations take signal's falling, rising and spike suppression
747  * times in to account. They can be found in Synopsys or Intel documentation.
748  *
749  * Here we snarf formulas and defaults from Linux driver to be able to use
750  * timing values provided by Intel LPSS driver "as is".
751  */
752 static int
753 ig4iic_clk_params(const struct ig4_hw *hw, int speed,
754     uint16_t *scl_hcnt, uint16_t *scl_lcnt, uint16_t *sda_hold)
755 {
756 	uint32_t thigh, tlow, tf_max;	/* nsec */
757 	uint32_t sda_fall_time;		/* nsec */
758         uint32_t scl_fall_time;		/* nsec */
759 
760 	switch (speed) {
761 	case IG4_CTL_SPEED_STD:
762 		thigh = IG4_SPEED_STD_THIGH;
763 		tlow = IG4_SPEED_STD_TLOW;
764 		tf_max = IG4_SPEED_STD_TF_MAX;
765 		break;
766 
767 	case IG4_CTL_SPEED_FAST:
768 		thigh = IG4_SPEED_FAST_THIGH;
769 		tlow = IG4_SPEED_FAST_TLOW;
770 		tf_max = IG4_SPEED_FAST_TF_MAX;
771 		break;
772 
773 	default:
774 		return (EINVAL);
775 	}
776 
777 	/* Use slowest falling time defaults to be on the safe side */
778 	sda_fall_time = hw->sda_fall_time == 0 ? tf_max : hw->sda_fall_time;
779 	*scl_hcnt = (uint16_t)
780 	    ((hw->ic_clock_rate * (thigh + sda_fall_time) + 500) / 1000 - 3);
781 
782 	scl_fall_time = hw->scl_fall_time == 0 ? tf_max : hw->scl_fall_time;
783 	*scl_lcnt = (uint16_t)
784 	    ((hw->ic_clock_rate * (tlow + scl_fall_time) + 500) / 1000 - 1);
785 
786 	/*
787 	 * There is no "known good" default value for tHD;DAT so keep SDA_HOLD
788 	 * intact if sda_hold_time value is not provided.
789 	 */
790 	if (hw->sda_hold_time != 0)
791 		*sda_hold = (uint16_t)
792 		    ((hw->ic_clock_rate * hw->sda_hold_time + 500) / 1000);
793 
794 	return (0);
795 }
796 
797 #ifdef DEV_ACPI
798 static ACPI_STATUS
799 ig4iic_acpi_params(ACPI_HANDLE handle, char *method,
800     uint16_t *scl_hcnt, uint16_t *scl_lcnt, uint16_t *sda_hold)
801 {
802 	ACPI_BUFFER buf;
803 	ACPI_OBJECT *obj, *elems;
804 	ACPI_STATUS status;
805 
806 	buf.Pointer = NULL;
807 	buf.Length = ACPI_ALLOCATE_BUFFER;
808 
809 	status = AcpiEvaluateObject(handle, method, NULL, &buf);
810 	if (ACPI_FAILURE(status))
811 		return (status);
812 
813 	status = AE_TYPE;
814 	obj = (ACPI_OBJECT *)buf.Pointer;
815 	if (obj->Type == ACPI_TYPE_PACKAGE && obj->Package.Count == 3) {
816 		elems = obj->Package.Elements;
817 		*scl_hcnt = elems[0].Integer.Value & IG4_SCL_CLOCK_MASK;
818 		*scl_lcnt = elems[1].Integer.Value & IG4_SCL_CLOCK_MASK;
819 		*sda_hold = elems[2].Integer.Value & IG4_SDA_TX_HOLD_MASK;
820 		status = AE_OK;
821 	}
822 
823 	AcpiOsFree(obj);
824 
825 	return (status);
826 }
827 #endif /* DEV_ACPI */
828 
829 static void
830 ig4iic_get_config(ig4iic_softc_t *sc)
831 {
832 	const struct ig4_hw *hw;
833 	uint32_t v;
834 #ifdef DEV_ACPI
835 	ACPI_HANDLE handle;
836 #endif
837 	/* Fetch default hardware config from controller */
838 	sc->cfg.version = reg_read(sc, IG4_REG_COMP_VER);
839 	sc->cfg.bus_speed = reg_read(sc, IG4_REG_CTL) & IG4_CTL_SPEED_MASK;
840 	sc->cfg.ss_scl_hcnt =
841 	    reg_read(sc, IG4_REG_SS_SCL_HCNT) & IG4_SCL_CLOCK_MASK;
842 	sc->cfg.ss_scl_lcnt =
843 	    reg_read(sc, IG4_REG_SS_SCL_LCNT) & IG4_SCL_CLOCK_MASK;
844 	sc->cfg.fs_scl_hcnt =
845 	    reg_read(sc, IG4_REG_FS_SCL_HCNT) & IG4_SCL_CLOCK_MASK;
846 	sc->cfg.fs_scl_lcnt =
847 	    reg_read(sc, IG4_REG_FS_SCL_LCNT) & IG4_SCL_CLOCK_MASK;
848 	sc->cfg.ss_sda_hold = sc->cfg.fs_sda_hold =
849 	    reg_read(sc, IG4_REG_SDA_HOLD) & IG4_SDA_TX_HOLD_MASK;
850 
851 	if (sc->cfg.bus_speed != IG4_CTL_SPEED_STD)
852 		sc->cfg.bus_speed = IG4_CTL_SPEED_FAST;
853 
854 	/* REG_COMP_PARAM1 is not documented in latest Intel specs */
855 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
856 		v = reg_read(sc, IG4_REG_COMP_PARAM1);
857 		if (IG4_PARAM1_TXFIFO_DEPTH(v) != 0)
858 			sc->cfg.txfifo_depth = IG4_PARAM1_TXFIFO_DEPTH(v);
859 		if (IG4_PARAM1_RXFIFO_DEPTH(v) != 0)
860 			sc->cfg.rxfifo_depth = IG4_PARAM1_RXFIFO_DEPTH(v);
861 	}
862 
863 	/* Override hardware config with IC_clock-based counter values */
864 	if (ig4_timings < 2 && sc->version < nitems(ig4iic_hw)) {
865 		hw = &ig4iic_hw[sc->version];
866 		sc->cfg.bus_speed = IG4_CTL_SPEED_FAST;
867 		ig4iic_clk_params(hw, IG4_CTL_SPEED_STD, &sc->cfg.ss_scl_hcnt,
868 		    &sc->cfg.ss_scl_lcnt, &sc->cfg.ss_sda_hold);
869 		ig4iic_clk_params(hw, IG4_CTL_SPEED_FAST, &sc->cfg.fs_scl_hcnt,
870 		    &sc->cfg.fs_scl_lcnt, &sc->cfg.fs_sda_hold);
871 		if (hw->txfifo_depth != 0)
872 			sc->cfg.txfifo_depth = hw->txfifo_depth;
873 		if (hw->rxfifo_depth != 0)
874 			sc->cfg.rxfifo_depth = hw->rxfifo_depth;
875 	} else if (ig4_timings == 2) {
876 		/*
877 		 * Timings of original ig4 driver:
878 		 * Program based on a 25000 Hz clock.  This is a bit of a
879 		 * hack (obviously).  The defaults are 400 and 470 for standard
880 		 * and 60 and 130 for fast.  The defaults for standard fail
881 		 * utterly (presumably cause an abort) because the clock time
882 		 * is ~18.8ms by default.  This brings it down to ~4ms.
883 		 */
884 		sc->cfg.bus_speed = IG4_CTL_SPEED_STD;
885 		sc->cfg.ss_scl_hcnt = sc->cfg.fs_scl_hcnt = 100;
886 		sc->cfg.ss_scl_lcnt = sc->cfg.fs_scl_lcnt = 125;
887 		if (sc->version == IG4_SKYLAKE)
888 			sc->cfg.ss_sda_hold = sc->cfg.fs_sda_hold = 28;
889 	}
890 
891 #ifdef DEV_ACPI
892 	/* Evaluate SSCN and FMCN ACPI methods to fetch timings */
893 	if (ig4_timings == 0 && (handle = acpi_get_handle(sc->dev)) != NULL) {
894 		ig4iic_acpi_params(handle, "SSCN", &sc->cfg.ss_scl_hcnt,
895 		    &sc->cfg.ss_scl_lcnt, &sc->cfg.ss_sda_hold);
896 		ig4iic_acpi_params(handle, "FMCN", &sc->cfg.fs_scl_hcnt,
897 		    &sc->cfg.fs_scl_lcnt, &sc->cfg.fs_sda_hold);
898 	}
899 #endif
900 
901 	if (bootverbose) {
902 		device_printf(sc->dev, "Controller parameters:\n");
903 		printf("  Speed: %s\n",
904 		    sc->cfg.bus_speed == IG4_CTL_SPEED_STD ? "Std" : "Fast");
905 		printf("  Regs:  HCNT  :LCNT  :SDAHLD\n");
906 		printf("  Std:   0x%04hx:0x%04hx:0x%04hx\n",
907 		    sc->cfg.ss_scl_hcnt, sc->cfg.ss_scl_lcnt,
908 		    sc->cfg.ss_sda_hold);
909 		printf("  Fast:  0x%04hx:0x%04hx:0x%04hx\n",
910 		    sc->cfg.fs_scl_hcnt, sc->cfg.fs_scl_lcnt,
911 		    sc->cfg.fs_sda_hold);
912 	}
913 }
914 
915 static int
916 ig4iic_set_config(ig4iic_softc_t *sc, bool reset)
917 {
918 	uint32_t v;
919 
920 	v = reg_read(sc, IG4_REG_DEVIDLE_CTRL);
921 	if (IG4_HAS_ADDREGS(sc->version) && (v & IG4_RESTORE_REQUIRED)) {
922 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, IG4_DEVICE_IDLE | IG4_RESTORE_REQUIRED);
923 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, 0);
924 		pause("i2crst", 1);
925 		reset = true;
926 	}
927 
928 	if ((sc->version == IG4_HASWELL || sc->version == IG4_ATOM) && reset) {
929 		reg_write(sc, IG4_REG_RESETS_HSW, IG4_RESETS_ASSERT_HSW);
930 		reg_write(sc, IG4_REG_RESETS_HSW, IG4_RESETS_DEASSERT_HSW);
931 	} else if (IG4_HAS_ADDREGS(sc->version) && reset) {
932 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_ASSERT_SKL);
933 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_DEASSERT_SKL);
934 	}
935 
936 	if (sc->version == IG4_ATOM)
937 		v = reg_read(sc, IG4_REG_COMP_TYPE);
938 
939 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
940 		v = reg_read(sc, IG4_REG_COMP_PARAM1);
941 		v = reg_read(sc, IG4_REG_GENERAL);
942 		/*
943 		 * The content of IG4_REG_GENERAL is different for each
944 		 * controller version.
945 		 */
946 		if (sc->version == IG4_HASWELL &&
947 		    (v & IG4_GENERAL_SWMODE) == 0) {
948 			v |= IG4_GENERAL_SWMODE;
949 			reg_write(sc, IG4_REG_GENERAL, v);
950 			v = reg_read(sc, IG4_REG_GENERAL);
951 		}
952 	}
953 
954 	if (sc->version == IG4_HASWELL) {
955 		v = reg_read(sc, IG4_REG_SW_LTR_VALUE);
956 		v = reg_read(sc, IG4_REG_AUTO_LTR_VALUE);
957 	} else if (IG4_HAS_ADDREGS(sc->version)) {
958 		v = reg_read(sc, IG4_REG_ACTIVE_LTR_VALUE);
959 		v = reg_read(sc, IG4_REG_IDLE_LTR_VALUE);
960 	}
961 
962 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
963 		v = reg_read(sc, IG4_REG_COMP_VER);
964 		if (v < IG4_COMP_MIN_VER)
965 			return(ENXIO);
966 	}
967 
968 	if (set_controller(sc, 0)) {
969 		device_printf(sc->dev, "controller error during attach-1\n");
970 		return (ENXIO);
971 	}
972 
973 	reg_read(sc, IG4_REG_CLR_INTR);
974 	reg_write(sc, IG4_REG_INTR_MASK, 0);
975 	sc->intr_mask = 0;
976 
977 	reg_write(sc, IG4_REG_SS_SCL_HCNT, sc->cfg.ss_scl_hcnt);
978 	reg_write(sc, IG4_REG_SS_SCL_LCNT, sc->cfg.ss_scl_lcnt);
979 	reg_write(sc, IG4_REG_FS_SCL_HCNT, sc->cfg.fs_scl_hcnt);
980 	reg_write(sc, IG4_REG_FS_SCL_LCNT, sc->cfg.fs_scl_lcnt);
981 	reg_write(sc, IG4_REG_SDA_HOLD,
982 	    (sc->cfg.bus_speed  & IG4_CTL_SPEED_MASK) == IG4_CTL_SPEED_STD ?
983 	      sc->cfg.ss_sda_hold : sc->cfg.fs_sda_hold);
984 
985 	reg_write(sc, IG4_REG_RX_TL, 0);
986 	reg_write(sc, IG4_REG_TX_TL, 0);
987 
988 	reg_write(sc, IG4_REG_CTL,
989 		  IG4_CTL_MASTER |
990 		  IG4_CTL_SLAVE_DISABLE |
991 		  IG4_CTL_RESTARTEN |
992 		  (sc->cfg.bus_speed & IG4_CTL_SPEED_MASK));
993 
994 	/* Force setting of the target address on the next transfer */
995 	sc->slave_valid = false;
996 
997 	return (0);
998 }
999 
1000 static void
1001 ig4iic_get_fifo(ig4iic_softc_t *sc)
1002 {
1003 	uint32_t v;
1004 
1005 	/*
1006 	 * Hardware does not allow FIFO Threshold Levels value to be set larger
1007 	 * than the depth of the buffer.  If an attempt is made to do that, the
1008 	 * actual value set will be the maximum depth of the buffer.
1009 	 */
1010 	if (sc->cfg.txfifo_depth == 0) {
1011 		v = reg_read(sc, IG4_REG_TX_TL);
1012 		reg_write(sc, IG4_REG_TX_TL, v | IG4_FIFO_MASK);
1013 		sc->cfg.txfifo_depth =
1014 		    (reg_read(sc, IG4_REG_TX_TL) & IG4_FIFO_MASK) + 1;
1015 		reg_write(sc, IG4_REG_TX_TL, v);
1016 	}
1017 	if (sc->cfg.rxfifo_depth == 0) {
1018 		v = reg_read(sc, IG4_REG_RX_TL);
1019 		reg_write(sc, IG4_REG_RX_TL, v | IG4_FIFO_MASK);
1020 		sc->cfg.rxfifo_depth =
1021 		    (reg_read(sc, IG4_REG_RX_TL) & IG4_FIFO_MASK) + 1;
1022 		reg_write(sc, IG4_REG_RX_TL, v);
1023 	}
1024 	if (bootverbose) {
1025 		printf("  FIFO:  RX:0x%04x: TX:0x%04x\n",
1026 		    sc->cfg.rxfifo_depth, sc->cfg.txfifo_depth);
1027 	}
1028 }
1029 
1030 /*
1031  * Called from ig4iic_pci_attach/detach()
1032  */
1033 int
1034 ig4iic_attach(ig4iic_softc_t *sc)
1035 {
1036 	int error;
1037 
1038 	mtx_init(&sc->io_lock, "IG4 I/O lock", NULL, MTX_SPIN);
1039 	sx_init(&sc->call_lock, "IG4 call lock");
1040 
1041 	ig4iic_get_config(sc);
1042 
1043 	error = ig4iic_set_config(sc, IG4_HAS_ADDREGS(sc->version));
1044 	if (error)
1045 		goto done;
1046 	ig4iic_get_fifo(sc);
1047 
1048 	sc->iicbus = device_add_child(sc->dev, "iicbus", DEVICE_UNIT_ANY);
1049 	if (sc->iicbus == NULL) {
1050 		device_printf(sc->dev, "iicbus driver not found\n");
1051 		error = ENXIO;
1052 		goto done;
1053 	}
1054 
1055 	if (set_controller(sc, IG4_I2C_ENABLE)) {
1056 		device_printf(sc->dev, "controller error during attach-2\n");
1057 		error = ENXIO;
1058 		goto done;
1059 	}
1060 	if (set_controller(sc, 0)) {
1061 		device_printf(sc->dev, "controller error during attach-3\n");
1062 		error = ENXIO;
1063 		goto done;
1064 	}
1065 	error = bus_setup_intr(sc->dev, sc->intr_res, INTR_TYPE_MISC | INTR_MPSAFE,
1066 			       ig4iic_intr, NULL, sc, &sc->intr_handle);
1067 	if (error) {
1068 		device_printf(sc->dev,
1069 			      "Unable to setup irq: error %d\n", error);
1070 	}
1071 
1072 	error = bus_generic_attach(sc->dev);
1073 	if (error) {
1074 		device_printf(sc->dev,
1075 			      "failed to attach child: error %d\n", error);
1076 	}
1077 
1078 done:
1079 	return (error);
1080 }
1081 
1082 int
1083 ig4iic_detach(ig4iic_softc_t *sc)
1084 {
1085 	int error;
1086 
1087 	if (device_is_attached(sc->dev)) {
1088 		error = bus_generic_detach(sc->dev);
1089 		if (error)
1090 			return (error);
1091 	}
1092 	if (sc->iicbus)
1093 		device_delete_child(sc->dev, sc->iicbus);
1094 	if (sc->intr_handle)
1095 		bus_teardown_intr(sc->dev, sc->intr_res, sc->intr_handle);
1096 
1097 	sx_xlock(&sc->call_lock);
1098 
1099 	sc->iicbus = NULL;
1100 	sc->intr_handle = NULL;
1101 	reg_write(sc, IG4_REG_INTR_MASK, 0);
1102 	set_controller(sc, 0);
1103 
1104 	sx_xunlock(&sc->call_lock);
1105 
1106 	mtx_destroy(&sc->io_lock);
1107 	sx_destroy(&sc->call_lock);
1108 
1109 	return (0);
1110 }
1111 
1112 int
1113 ig4iic_suspend(ig4iic_softc_t *sc)
1114 {
1115 	int error;
1116 
1117 	/* suspend all children */
1118 	error = bus_generic_suspend(sc->dev);
1119 
1120 	sx_xlock(&sc->call_lock);
1121 	set_controller(sc, 0);
1122 	if (IG4_HAS_ADDREGS(sc->version)) {
1123 		/*
1124 		 * Place the device in the idle state, just to be safe
1125 		 */
1126 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, IG4_DEVICE_IDLE);
1127 		/*
1128 		 * Controller can become dysfunctional if I2C lines are pulled
1129 		 * down when suspend procedure turns off power to I2C device.
1130 		 * Place device in the reset state to avoid this.
1131 		 */
1132 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_ASSERT_SKL);
1133 	}
1134 	sx_xunlock(&sc->call_lock);
1135 
1136 	return (error);
1137 }
1138 
1139 int ig4iic_resume(ig4iic_softc_t *sc)
1140 {
1141 	int error;
1142 
1143 	sx_xlock(&sc->call_lock);
1144 	if (ig4iic_set_config(sc, IG4_HAS_ADDREGS(sc->version)))
1145 		device_printf(sc->dev, "controller error during resume\n");
1146 	sx_xunlock(&sc->call_lock);
1147 
1148 	error = bus_generic_resume(sc->dev);
1149 
1150 	return (error);
1151 }
1152 
1153 /*
1154  * Interrupt Operation, see ig4_var.h for locking semantics.
1155  */
1156 static int
1157 ig4iic_intr(void *cookie)
1158 {
1159 	ig4iic_softc_t *sc = cookie;
1160 	int retval = FILTER_STRAY;
1161 
1162 	mtx_lock_spin(&sc->io_lock);
1163 	/* Ignore stray interrupts */
1164 	if (sc->intr_mask != 0 && reg_read(sc, IG4_REG_INTR_STAT) != 0) {
1165 		/* Interrupt bits are cleared in wait_intr() loop */
1166 		ig4iic_set_intr_mask(sc, 0);
1167 		wakeup(sc);
1168 		retval = FILTER_HANDLED;
1169 	}
1170 	mtx_unlock_spin(&sc->io_lock);
1171 
1172 	return (retval);
1173 }
1174 
1175 #define REGDUMP(sc, reg)	\
1176 	device_printf(sc->dev, "  %-23s %08x\n", #reg, reg_read(sc, reg))
1177 
1178 static void
1179 ig4iic_dump(ig4iic_softc_t *sc)
1180 {
1181 	device_printf(sc->dev, "ig4iic register dump:\n");
1182 	REGDUMP(sc, IG4_REG_CTL);
1183 	REGDUMP(sc, IG4_REG_TAR_ADD);
1184 	REGDUMP(sc, IG4_REG_SS_SCL_HCNT);
1185 	REGDUMP(sc, IG4_REG_SS_SCL_LCNT);
1186 	REGDUMP(sc, IG4_REG_FS_SCL_HCNT);
1187 	REGDUMP(sc, IG4_REG_FS_SCL_LCNT);
1188 	REGDUMP(sc, IG4_REG_INTR_STAT);
1189 	REGDUMP(sc, IG4_REG_INTR_MASK);
1190 	REGDUMP(sc, IG4_REG_RAW_INTR_STAT);
1191 	REGDUMP(sc, IG4_REG_RX_TL);
1192 	REGDUMP(sc, IG4_REG_TX_TL);
1193 	REGDUMP(sc, IG4_REG_I2C_EN);
1194 	REGDUMP(sc, IG4_REG_I2C_STA);
1195 	REGDUMP(sc, IG4_REG_TXFLR);
1196 	REGDUMP(sc, IG4_REG_RXFLR);
1197 	REGDUMP(sc, IG4_REG_SDA_HOLD);
1198 	REGDUMP(sc, IG4_REG_TX_ABRT_SOURCE);
1199 	REGDUMP(sc, IG4_REG_SLV_DATA_NACK);
1200 	REGDUMP(sc, IG4_REG_DMA_CTRL);
1201 	REGDUMP(sc, IG4_REG_DMA_TDLR);
1202 	REGDUMP(sc, IG4_REG_DMA_RDLR);
1203 	REGDUMP(sc, IG4_REG_SDA_SETUP);
1204 	REGDUMP(sc, IG4_REG_ENABLE_STATUS);
1205 	REGDUMP(sc, IG4_REG_COMP_PARAM1);
1206 	REGDUMP(sc, IG4_REG_COMP_VER);
1207 	if (sc->version == IG4_ATOM) {
1208 		REGDUMP(sc, IG4_REG_COMP_TYPE);
1209 		REGDUMP(sc, IG4_REG_CLK_PARMS);
1210 	}
1211 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
1212 		REGDUMP(sc, IG4_REG_RESETS_HSW);
1213 		REGDUMP(sc, IG4_REG_GENERAL);
1214 	} else if (sc->version == IG4_SKYLAKE) {
1215 		REGDUMP(sc, IG4_REG_RESETS_SKL);
1216 	}
1217 	if (sc->version == IG4_HASWELL) {
1218 		REGDUMP(sc, IG4_REG_SW_LTR_VALUE);
1219 		REGDUMP(sc, IG4_REG_AUTO_LTR_VALUE);
1220 	} else if (IG4_HAS_ADDREGS(sc->version)) {
1221 		REGDUMP(sc, IG4_REG_ACTIVE_LTR_VALUE);
1222 		REGDUMP(sc, IG4_REG_IDLE_LTR_VALUE);
1223 	}
1224 }
1225 #undef REGDUMP
1226 
1227 DRIVER_MODULE(iicbus, ig4iic, iicbus_driver, NULL, NULL);
1228 #ifdef DEV_ACPI
1229 DRIVER_MODULE(acpi_iicbus, ig4iic, acpi_iicbus_driver, NULL, NULL);
1230 #endif
1231 MODULE_DEPEND(ig4iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
1232 MODULE_VERSION(ig4iic, 1);
1233