xref: /freebsd-14.2/sys/dev/ichiic/ig4_iic.c (revision 60452092)
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 <[email protected]> and was subsequently ported
6  * to FreeBSD by Michael Gmelin <[email protected]>
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_HASWELL] = {
93 		.ic_clock_rate = 100,	/* MHz */
94 		.sda_hold_time = 90,	/* nsec */
95 		.txfifo_depth = 32,
96 		.rxfifo_depth = 32,
97 	},
98 	[IG4_ATOM] = {
99 		.ic_clock_rate = 100,
100 		.sda_fall_time = 280,
101 		.scl_fall_time = 240,
102 		.sda_hold_time = 60,
103 		.txfifo_depth = 32,
104 		.rxfifo_depth = 32,
105 	},
106 	[IG4_SKYLAKE] = {
107 		.ic_clock_rate = 120,
108 		.sda_hold_time = 230,
109 	},
110 	[IG4_APL] = {
111 		.ic_clock_rate = 133,
112 		.sda_fall_time = 171,
113 		.scl_fall_time = 208,
114 		.sda_hold_time = 207,
115 	},
116 	[IG4_CANNONLAKE] = {
117 		.ic_clock_rate = 216,
118 		.sda_hold_time = 230,
119 	},
120 	[IG4_TIGERLAKE] = {
121 		.ic_clock_rate = 133,
122 		.sda_fall_time = 171,
123 		.scl_fall_time = 208,
124 		.sda_hold_time = 42,
125 	},
126 	[IG4_GEMINILAKE] = {
127 		.ic_clock_rate = 133,
128 		.sda_fall_time = 171,
129 		.scl_fall_time = 290,
130 		.sda_hold_time = 313,
131 	},
132 };
133 
134 static int ig4iic_set_config(ig4iic_softc_t *sc, bool reset);
135 static driver_filter_t ig4iic_intr;
136 static void ig4iic_dump(ig4iic_softc_t *sc);
137 
138 static int ig4_dump;
139 SYSCTL_INT(_debug, OID_AUTO, ig4_dump, CTLFLAG_RW,
140 	   &ig4_dump, 0, "Dump controller registers");
141 
142 /*
143  * Clock registers initialization control
144  * 0 - Try read clock registers from ACPI and fallback to p.1.
145  * 1 - Calculate values based on controller type (IC clock rate).
146  * 2 - Use values inherited from DragonflyBSD driver (old behavior).
147  * 3 - Keep clock registers intact.
148  */
149 static int ig4_timings;
150 SYSCTL_INT(_debug, OID_AUTO, ig4_timings, CTLFLAG_RDTUN, &ig4_timings, 0,
151     "Controller timings 0=ACPI, 1=predefined, 2=legacy, 3=do not change");
152 
153 /*
154  * Low-level inline support functions
155  */
156 static __inline void
reg_write(ig4iic_softc_t * sc,uint32_t reg,uint32_t value)157 reg_write(ig4iic_softc_t *sc, uint32_t reg, uint32_t value)
158 {
159 	bus_write_4(sc->regs_res, reg, value);
160 	bus_barrier(sc->regs_res, reg, 4, BUS_SPACE_BARRIER_WRITE);
161 }
162 
163 static __inline uint32_t
reg_read(ig4iic_softc_t * sc,uint32_t reg)164 reg_read(ig4iic_softc_t *sc, uint32_t reg)
165 {
166 	uint32_t value;
167 
168 	bus_barrier(sc->regs_res, reg, 4, BUS_SPACE_BARRIER_READ);
169 	value = bus_read_4(sc->regs_res, reg);
170 	return (value);
171 }
172 
173 static void
ig4iic_set_intr_mask(ig4iic_softc_t * sc,uint32_t val)174 ig4iic_set_intr_mask(ig4iic_softc_t *sc, uint32_t val)
175 {
176 	if (sc->intr_mask != val) {
177 		reg_write(sc, IG4_REG_INTR_MASK, val);
178 		sc->intr_mask = val;
179 	}
180 }
181 
182 static int
intrstat2iic(ig4iic_softc_t * sc,uint32_t val)183 intrstat2iic(ig4iic_softc_t *sc, uint32_t val)
184 {
185 	uint32_t src;
186 
187 	if (val & IG4_INTR_RX_UNDER)
188 		reg_read(sc, IG4_REG_CLR_RX_UNDER);
189 	if (val & IG4_INTR_RX_OVER)
190 		reg_read(sc, IG4_REG_CLR_RX_OVER);
191 	if (val & IG4_INTR_TX_OVER)
192 		reg_read(sc, IG4_REG_CLR_TX_OVER);
193 
194 	if (val & IG4_INTR_TX_ABRT) {
195 		src = reg_read(sc, IG4_REG_TX_ABRT_SOURCE);
196 		reg_read(sc, IG4_REG_CLR_TX_ABORT);
197 		/* User-requested abort. Not really a error */
198 		if (src & IG4_ABRTSRC_TRANSFER)
199 			return (IIC_ESTATUS);
200 		/* Master has lost arbitration */
201 		if (src & IG4_ABRTSRC_ARBLOST)
202 			return (IIC_EBUSBSY);
203 		/* Did not receive an acknowledge from the remote slave */
204 		if (src & (IG4_ABRTSRC_TXNOACK_ADDR7 |
205 			   IG4_ABRTSRC_TXNOACK_ADDR10_1 |
206 			   IG4_ABRTSRC_TXNOACK_ADDR10_2 |
207 			   IG4_ABRTSRC_TXNOACK_DATA |
208 			   IG4_ABRTSRC_GENCALL_NOACK))
209 			return (IIC_ENOACK);
210 		/* Programming errors */
211 		if (src & (IG4_ABRTSRC_GENCALL_READ |
212 			   IG4_ABRTSRC_NORESTART_START |
213 			   IG4_ABRTSRC_NORESTART_10))
214 			return (IIC_ENOTSUPP);
215 		/* Other errors */
216 		if (src & IG4_ABRTSRC_ACKED_START)
217 			return (IIC_EBUSERR);
218 	}
219 	/*
220 	 * TX_OVER, RX_OVER and RX_UNDER are caused by wrong RX/TX FIFO depth
221 	 * detection or driver's read/write pipelining errors.
222 	 */
223 	if (val & (IG4_INTR_TX_OVER | IG4_INTR_RX_OVER))
224 		return (IIC_EOVERFLOW);
225 	if (val & IG4_INTR_RX_UNDER)
226 		return (IIC_EUNDERFLOW);
227 
228 	return (IIC_NOERR);
229 }
230 
231 /*
232  * Enable or disable the controller and wait for the controller to acknowledge
233  * the state change.
234  */
235 static int
set_controller(ig4iic_softc_t * sc,uint32_t ctl)236 set_controller(ig4iic_softc_t *sc, uint32_t ctl)
237 {
238 	int retry;
239 	int error;
240 	uint32_t v;
241 
242 	/*
243 	 * When the controller is enabled, interrupt on STOP detect
244 	 * or receive character ready and clear pending interrupts.
245 	 */
246 	ig4iic_set_intr_mask(sc, 0);
247 	if (ctl & IG4_I2C_ENABLE)
248 		reg_read(sc, IG4_REG_CLR_INTR);
249 
250 	reg_write(sc, IG4_REG_I2C_EN, ctl);
251 	error = IIC_ETIMEOUT;
252 
253 	for (retry = 100; retry > 0; --retry) {
254 		v = reg_read(sc, IG4_REG_ENABLE_STATUS);
255 		if (((v ^ ctl) & IG4_I2C_ENABLE) == 0) {
256 			error = 0;
257 			break;
258 		}
259 		pause("i2cslv", 1);
260 	}
261 	return (error);
262 }
263 
264 /*
265  * Wait up to 25ms for the requested interrupt using a 25uS polling loop.
266  */
267 static int
wait_intr(ig4iic_softc_t * sc,uint32_t intr)268 wait_intr(ig4iic_softc_t *sc, uint32_t intr)
269 {
270 	uint32_t v;
271 	int error;
272 	int txlvl = -1;
273 	u_int count_us = 0;
274 	u_int limit_us = 1000000; /* 1sec */
275 
276 	for (;;) {
277 		/*
278 		 * Check requested status
279 		 */
280 		v = reg_read(sc, IG4_REG_RAW_INTR_STAT);
281 		error = intrstat2iic(sc, v & IG4_INTR_ERR_MASK);
282 		if (error || (v & intr))
283 			break;
284 
285 		/*
286 		 * When waiting for the transmit FIFO to become empty,
287 		 * reset the timeout if we see a change in the transmit
288 		 * FIFO level as progress is being made.
289 		 */
290 		if (intr & (IG4_INTR_TX_EMPTY | IG4_INTR_STOP_DET)) {
291 			v = reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK;
292 			if (txlvl != v) {
293 				txlvl = v;
294 				count_us = 0;
295 			}
296 		}
297 
298 		/*
299 		 * Stop if we've run out of time.
300 		 */
301 		if (count_us >= limit_us) {
302 			error = IIC_ETIMEOUT;
303 			break;
304 		}
305 
306 		/*
307 		 * When polling is not requested let the interrupt do its work.
308 		 */
309 		if (!DO_POLL(sc)) {
310 			mtx_lock_spin(&sc->io_lock);
311 			ig4iic_set_intr_mask(sc, intr | IG4_INTR_ERR_MASK);
312 			msleep_spin(sc, &sc->io_lock, "i2cwait",
313 				  (hz + 99) / 100); /* sleep up to 10ms */
314 			ig4iic_set_intr_mask(sc, 0);
315 			mtx_unlock_spin(&sc->io_lock);
316 			count_us += 10000;
317 		} else {
318 			DELAY(25);
319 			count_us += 25;
320 		}
321 	}
322 
323 	return (error);
324 }
325 
326 /*
327  * Set the slave address.  The controller must be disabled when
328  * changing the address.
329  *
330  * This operation does not issue anything to the I2C bus but sets
331  * the target address for when the controller later issues a START.
332  */
333 static void
set_slave_addr(ig4iic_softc_t * sc,uint8_t slave)334 set_slave_addr(ig4iic_softc_t *sc, uint8_t slave)
335 {
336 	uint32_t tar;
337 	uint32_t ctl;
338 	bool use_10bit;
339 
340 	use_10bit = false;
341 	if (sc->slave_valid && sc->last_slave == slave &&
342 	    sc->use_10bit == use_10bit) {
343 		return;
344 	}
345 	sc->use_10bit = use_10bit;
346 
347 	/*
348 	 * Wait for TXFIFO to drain before disabling the controller.
349 	 */
350 	reg_write(sc, IG4_REG_TX_TL, 0);
351 	wait_intr(sc, IG4_INTR_TX_EMPTY);
352 
353 	set_controller(sc, 0);
354 	ctl = reg_read(sc, IG4_REG_CTL);
355 	ctl &= ~IG4_CTL_10BIT;
356 	ctl |= IG4_CTL_RESTARTEN;
357 
358 	tar = slave;
359 	if (sc->use_10bit) {
360 		tar |= IG4_TAR_10BIT;
361 		ctl |= IG4_CTL_10BIT;
362 	}
363 	reg_write(sc, IG4_REG_CTL, ctl);
364 	reg_write(sc, IG4_REG_TAR_ADD, tar);
365 	set_controller(sc, IG4_I2C_ENABLE);
366 	sc->slave_valid = true;
367 	sc->last_slave = slave;
368 }
369 
370 /*
371  *				IICBUS API FUNCTIONS
372  */
373 static int
ig4iic_xfer_start(ig4iic_softc_t * sc,uint16_t slave,bool repeated_start)374 ig4iic_xfer_start(ig4iic_softc_t *sc, uint16_t slave, bool repeated_start)
375 {
376 	set_slave_addr(sc, slave >> 1);
377 
378 	if (!repeated_start) {
379 		/*
380 		 * Clear any previous TX/RX FIFOs overflow/underflow bits
381 		 * and I2C bus STOP condition.
382 		 */
383 		reg_read(sc, IG4_REG_CLR_INTR);
384 	}
385 
386 	return (0);
387 }
388 
389 static bool
ig4iic_xfer_is_started(ig4iic_softc_t * sc)390 ig4iic_xfer_is_started(ig4iic_softc_t *sc)
391 {
392 	/*
393 	 * It requires that no IG4_REG_CLR_INTR or IG4_REG_CLR_START/STOP_DET
394 	 * register reads is issued after START condition.
395 	 */
396 	return ((reg_read(sc, IG4_REG_RAW_INTR_STAT) &
397 	    (IG4_INTR_START_DET | IG4_INTR_STOP_DET)) == IG4_INTR_START_DET);
398 }
399 
400 static int
ig4iic_xfer_abort(ig4iic_softc_t * sc)401 ig4iic_xfer_abort(ig4iic_softc_t *sc)
402 {
403 	int error;
404 
405 	/* Request send of STOP condition and flush of TX FIFO */
406 	set_controller(sc, IG4_I2C_ABORT | IG4_I2C_ENABLE);
407 	/*
408 	 * Wait for the TX_ABRT interrupt with ABRTSRC_TRANSFER
409 	 * bit set in TX_ABRT_SOURCE register.
410 	 */
411 	error = wait_intr(sc, IG4_INTR_STOP_DET);
412 	set_controller(sc, IG4_I2C_ENABLE);
413 
414 	return (error == IIC_ESTATUS ? 0 : error);
415 }
416 
417 /*
418  * Amount of unread data before next burst to get better I2C bus utilization.
419  * 2 bytes is enough in FAST mode. 8 bytes is better in FAST+ and HIGH modes.
420  * Intel-recommended value is 16 for DMA transfers with 64-byte depth FIFOs.
421  */
422 #define	IG4_FIFO_LOWAT	2
423 
424 static int
ig4iic_read(ig4iic_softc_t * sc,uint8_t * buf,uint16_t len,bool repeated_start,bool stop)425 ig4iic_read(ig4iic_softc_t *sc, uint8_t *buf, uint16_t len,
426     bool repeated_start, bool stop)
427 {
428 	uint32_t cmd;
429 	int requested = 0;
430 	int received = 0;
431 	int burst, target, lowat = 0;
432 	int error;
433 
434 	if (len == 0)
435 		return (0);
436 
437 	while (received < len) {
438 		/* Ensure we have some free space in TXFIFO */
439 		burst = sc->cfg.txfifo_depth -
440 		    (reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
441 		if (burst <= 0) {
442 			reg_write(sc, IG4_REG_TX_TL, IG4_FIFO_LOWAT);
443 			error = wait_intr(sc, IG4_INTR_TX_EMPTY);
444 			if (error)
445 				break;
446 			burst = sc->cfg.txfifo_depth -
447 			    (reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
448 		}
449 		/* Ensure we have enough free space in RXFIFO */
450 		burst = MIN(burst, sc->cfg.rxfifo_depth -
451 		    (requested - received));
452 		target = MIN(requested + burst, (int)len);
453 		while (requested < target) {
454 			cmd = IG4_DATA_COMMAND_RD;
455 			if (repeated_start && requested == 0)
456 				cmd |= IG4_DATA_RESTART;
457 			if (stop && requested == len - 1)
458 				cmd |= IG4_DATA_STOP;
459 			reg_write(sc, IG4_REG_DATA_CMD, cmd);
460 			requested++;
461 		}
462 		/* Leave some data queued to maintain the hardware pipeline */
463 		lowat = 0;
464 		if (requested != len && requested - received > IG4_FIFO_LOWAT)
465 			lowat = IG4_FIFO_LOWAT;
466 		/* After TXFLR fills up, clear it by reading available data */
467 		while (received < requested - lowat) {
468 			burst = MIN(requested - received,
469 			    reg_read(sc, IG4_REG_RXFLR) & IG4_FIFOLVL_MASK);
470 			if (burst > 0) {
471 				while (burst--)
472 					buf[received++] = 0xFF &
473 					    reg_read(sc, IG4_REG_DATA_CMD);
474 			} else {
475 				reg_write(sc, IG4_REG_RX_TL,
476 				    requested - received - lowat - 1);
477 				error = wait_intr(sc, IG4_INTR_RX_FULL);
478 				if (error)
479 					goto out;
480 			}
481 		}
482 	}
483 out:
484 	return (error);
485 }
486 
487 static int
ig4iic_write(ig4iic_softc_t * sc,uint8_t * buf,uint16_t len,bool repeated_start,bool stop)488 ig4iic_write(ig4iic_softc_t *sc, uint8_t *buf, uint16_t len,
489     bool repeated_start, bool stop)
490 {
491 	uint32_t cmd;
492 	int sent = 0;
493 	int burst, target;
494 	int error, lowat;
495 
496 	if (len == 0)
497 		return (0);
498 
499 	while (sent < len) {
500 		burst = sc->cfg.txfifo_depth -
501 		    (reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
502 		target = MIN(sent + burst, (int)len);
503 		while (sent < target) {
504 			cmd = buf[sent];
505 			if (repeated_start && sent == 0)
506 				cmd |= IG4_DATA_RESTART;
507 			if (stop && sent == len - 1)
508 				cmd |= IG4_DATA_STOP;
509 			reg_write(sc, IG4_REG_DATA_CMD, cmd);
510 			sent++;
511 		}
512 		if (sent < len) {
513 			if (len - sent <= sc->cfg.txfifo_depth)
514 				lowat = sc->cfg.txfifo_depth - (len - sent);
515 			else
516 				lowat = IG4_FIFO_LOWAT;
517 			reg_write(sc, IG4_REG_TX_TL, lowat);
518 			error = wait_intr(sc, IG4_INTR_TX_EMPTY);
519 			if (error)
520 				break;
521 		}
522 	}
523 
524 	return (error);
525 }
526 
527 int
ig4iic_transfer(device_t dev,struct iic_msg * msgs,uint32_t nmsgs)528 ig4iic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
529 {
530 	ig4iic_softc_t *sc = device_get_softc(dev);
531 	const char *reason = NULL;
532 	uint32_t i;
533 	int error;
534 	int unit;
535 	bool rpstart;
536 	bool stop;
537 	bool allocated;
538 
539 	/*
540 	 * The hardware interface imposes limits on allowed I2C messages.
541 	 * It is not possible to explicitly send a start or stop.
542 	 * They are automatically sent (or not sent, depending on the
543 	 * configuration) when a data byte is transferred.
544 	 * For this reason it's impossible to send a message with no data
545 	 * at all (like an SMBus quick message).
546 	 * The start condition is automatically generated after the stop
547 	 * condition, so it's impossible to not have a start after a stop.
548 	 * The repeated start condition is automatically sent if a change
549 	 * of the transfer direction happens, so it's impossible to have
550 	 * a change of direction without a (repeated) start.
551 	 * The repeated start can be forced even without the change of
552 	 * direction.
553 	 * Changing the target slave address requires resetting the hardware
554 	 * state, so it's impossible to do that without the stop followed
555 	 * by the start.
556 	 */
557 	for (i = 0; i < nmsgs; i++) {
558 #if 0
559 		if (i == 0 && (msgs[i].flags & IIC_M_NOSTART) != 0) {
560 			reason = "first message without start";
561 			break;
562 		}
563 		if (i == nmsgs - 1 && (msgs[i].flags & IIC_M_NOSTOP) != 0) {
564 			reason = "last message without stop";
565 			break;
566 		}
567 #endif
568 		if (msgs[i].len == 0) {
569 			reason = "message with no data";
570 			break;
571 		}
572 		if (i > 0) {
573 			if ((msgs[i].flags & IIC_M_NOSTART) != 0 &&
574 			    (msgs[i - 1].flags & IIC_M_NOSTOP) == 0) {
575 				reason = "stop not followed by start";
576 				break;
577 			}
578 			if ((msgs[i - 1].flags & IIC_M_NOSTOP) != 0 &&
579 			    msgs[i].slave != msgs[i - 1].slave) {
580 				reason = "change of slave without stop";
581 				break;
582 			}
583 			if ((msgs[i].flags & IIC_M_NOSTART) != 0 &&
584 			    (msgs[i].flags & IIC_M_RD) !=
585 			    (msgs[i - 1].flags & IIC_M_RD)) {
586 				reason = "change of direction without repeated"
587 				    " start";
588 				break;
589 			}
590 		}
591 	}
592 	if (reason != NULL) {
593 		if (bootverbose)
594 			device_printf(dev, "%s\n", reason);
595 		return (IIC_ENOTSUPP);
596 	}
597 
598 	/* Check if device is already allocated with iicbus_request_bus() */
599 	allocated = sx_xlocked(&sc->call_lock) != 0;
600 	if (!allocated)
601 		sx_xlock(&sc->call_lock);
602 
603 	/* Debugging - dump registers. */
604 	if (ig4_dump) {
605 		unit = device_get_unit(dev);
606 		if (ig4_dump & (1 << unit)) {
607 			ig4_dump &= ~(1 << unit);
608 			ig4iic_dump(sc);
609 		}
610 	}
611 
612 	/*
613 	 * Clear any previous abort condition that may have been holding
614 	 * the txfifo in reset.
615 	 */
616 	reg_read(sc, IG4_REG_CLR_TX_ABORT);
617 
618 	rpstart = false;
619 	error = 0;
620 	for (i = 0; i < nmsgs; i++) {
621 		if ((msgs[i].flags & IIC_M_NOSTART) == 0) {
622 			error = ig4iic_xfer_start(sc, msgs[i].slave, rpstart);
623 		} else {
624 			if (!sc->slave_valid ||
625 			    (msgs[i].slave >> 1) != sc->last_slave) {
626 				device_printf(dev, "start condition suppressed"
627 				    "but slave address is not set up");
628 				error = EINVAL;
629 				break;
630 			}
631 			rpstart = false;
632 		}
633 		if (error != 0)
634 			break;
635 
636 		stop = (msgs[i].flags & IIC_M_NOSTOP) == 0;
637 		if (msgs[i].flags & IIC_M_RD)
638 			error = ig4iic_read(sc, msgs[i].buf, msgs[i].len,
639 			    rpstart, stop);
640 		else
641 			error = ig4iic_write(sc, msgs[i].buf, msgs[i].len,
642 			    rpstart, stop);
643 
644 		/* Wait for error or stop condition occurred on the I2C bus */
645 		if (stop && error == 0) {
646 			error = wait_intr(sc, IG4_INTR_STOP_DET);
647 			if (error == 0)
648 				reg_read(sc, IG4_REG_CLR_INTR);
649 		}
650 
651 		if (error != 0) {
652 			/*
653 			 * Send STOP condition if it's not done yet and flush
654 			 * both FIFOs. Do a controller soft reset if transfer
655 			 * abort is failed.
656 			 */
657 			if (ig4iic_xfer_is_started(sc) &&
658 			    ig4iic_xfer_abort(sc) != 0) {
659 				device_printf(sc->dev, "Failed to abort "
660 				    "transfer. Do the controller reset.\n");
661 				ig4iic_set_config(sc, true);
662 			} else {
663 				while (reg_read(sc, IG4_REG_I2C_STA) &
664 				    IG4_STATUS_RX_NOTEMPTY)
665 					reg_read(sc, IG4_REG_DATA_CMD);
666 				reg_read(sc, IG4_REG_TX_ABRT_SOURCE);
667 				reg_read(sc, IG4_REG_CLR_INTR);
668 			}
669 			break;
670 		}
671 
672 		rpstart = !stop;
673 	}
674 
675 	if (!allocated)
676 		sx_unlock(&sc->call_lock);
677 	return (error);
678 }
679 
680 int
ig4iic_reset(device_t dev,u_char speed,u_char addr,u_char * oldaddr)681 ig4iic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
682 {
683 	ig4iic_softc_t *sc = device_get_softc(dev);
684 	bool allocated;
685 
686 	allocated = sx_xlocked(&sc->call_lock) != 0;
687 	if (!allocated)
688 		sx_xlock(&sc->call_lock);
689 
690 	/* TODO handle speed configuration? */
691 	if (oldaddr != NULL)
692 		*oldaddr = sc->last_slave << 1;
693 	set_slave_addr(sc, addr >> 1);
694 	if (addr == IIC_UNKNOWN)
695 		sc->slave_valid = false;
696 
697 	if (!allocated)
698 		sx_unlock(&sc->call_lock);
699 	return (0);
700 }
701 
702 int
ig4iic_callback(device_t dev,int index,caddr_t data)703 ig4iic_callback(device_t dev, int index, caddr_t data)
704 {
705 	ig4iic_softc_t *sc = device_get_softc(dev);
706 	int error = 0;
707 	int how;
708 
709 	switch (index) {
710 	case IIC_REQUEST_BUS:
711 		/* force polling if ig4iic is requested with IIC_DONTWAIT */
712 		how = *(int *)data;
713 		if ((how & IIC_WAIT) == 0) {
714 			if (sx_try_xlock(&sc->call_lock) == 0)
715 				error = IIC_EBUSBSY;
716 			else
717 				sc->poll = true;
718 		} else
719 			sx_xlock(&sc->call_lock);
720 		break;
721 
722 	case IIC_RELEASE_BUS:
723 		sc->poll = false;
724 		sx_unlock(&sc->call_lock);
725 		break;
726 
727 	default:
728 		error = errno2iic(EINVAL);
729 	}
730 
731 	return (error);
732 }
733 
734 /*
735  * Clock register values can be calculated with following rough equations:
736  * SCL_HCNT = ceil(IC clock rate * tHIGH)
737  * SCL_LCNT = ceil(IC clock rate * tLOW)
738  * SDA_HOLD = ceil(IC clock rate * SDA hold time)
739  * Precise equations take signal's falling, rising and spike suppression
740  * times in to account. They can be found in Synopsys or Intel documentation.
741  *
742  * Here we snarf formulas and defaults from Linux driver to be able to use
743  * timing values provided by Intel LPSS driver "as is".
744  */
745 static int
ig4iic_clk_params(const struct ig4_hw * hw,int speed,uint16_t * scl_hcnt,uint16_t * scl_lcnt,uint16_t * sda_hold)746 ig4iic_clk_params(const struct ig4_hw *hw, int speed,
747     uint16_t *scl_hcnt, uint16_t *scl_lcnt, uint16_t *sda_hold)
748 {
749 	uint32_t thigh, tlow, tf_max;	/* nsec */
750 	uint32_t sda_fall_time;		/* nsec */
751         uint32_t scl_fall_time;		/* nsec */
752 
753 	switch (speed) {
754 	case IG4_CTL_SPEED_STD:
755 		thigh = IG4_SPEED_STD_THIGH;
756 		tlow = IG4_SPEED_STD_TLOW;
757 		tf_max = IG4_SPEED_STD_TF_MAX;
758 		break;
759 
760 	case IG4_CTL_SPEED_FAST:
761 		thigh = IG4_SPEED_FAST_THIGH;
762 		tlow = IG4_SPEED_FAST_TLOW;
763 		tf_max = IG4_SPEED_FAST_TF_MAX;
764 		break;
765 
766 	default:
767 		return (EINVAL);
768 	}
769 
770 	/* Use slowest falling time defaults to be on the safe side */
771 	sda_fall_time = hw->sda_fall_time == 0 ? tf_max : hw->sda_fall_time;
772 	*scl_hcnt = (uint16_t)
773 	    ((hw->ic_clock_rate * (thigh + sda_fall_time) + 500) / 1000 - 3);
774 
775 	scl_fall_time = hw->scl_fall_time == 0 ? tf_max : hw->scl_fall_time;
776 	*scl_lcnt = (uint16_t)
777 	    ((hw->ic_clock_rate * (tlow + scl_fall_time) + 500) / 1000 - 1);
778 
779 	/*
780 	 * There is no "known good" default value for tHD;DAT so keep SDA_HOLD
781 	 * intact if sda_hold_time value is not provided.
782 	 */
783 	if (hw->sda_hold_time != 0)
784 		*sda_hold = (uint16_t)
785 		    ((hw->ic_clock_rate * hw->sda_hold_time + 500) / 1000);
786 
787 	return (0);
788 }
789 
790 #ifdef DEV_ACPI
791 static ACPI_STATUS
ig4iic_acpi_params(ACPI_HANDLE handle,char * method,uint16_t * scl_hcnt,uint16_t * scl_lcnt,uint16_t * sda_hold)792 ig4iic_acpi_params(ACPI_HANDLE handle, char *method,
793     uint16_t *scl_hcnt, uint16_t *scl_lcnt, uint16_t *sda_hold)
794 {
795 	ACPI_BUFFER buf;
796 	ACPI_OBJECT *obj, *elems;
797 	ACPI_STATUS status;
798 
799 	buf.Pointer = NULL;
800 	buf.Length = ACPI_ALLOCATE_BUFFER;
801 
802 	status = AcpiEvaluateObject(handle, method, NULL, &buf);
803 	if (ACPI_FAILURE(status))
804 		return (status);
805 
806 	status = AE_TYPE;
807 	obj = (ACPI_OBJECT *)buf.Pointer;
808 	if (obj->Type == ACPI_TYPE_PACKAGE && obj->Package.Count == 3) {
809 		elems = obj->Package.Elements;
810 		*scl_hcnt = elems[0].Integer.Value & IG4_SCL_CLOCK_MASK;
811 		*scl_lcnt = elems[1].Integer.Value & IG4_SCL_CLOCK_MASK;
812 		*sda_hold = elems[2].Integer.Value & IG4_SDA_TX_HOLD_MASK;
813 		status = AE_OK;
814 	}
815 
816 	AcpiOsFree(obj);
817 
818 	return (status);
819 }
820 #endif /* DEV_ACPI */
821 
822 static void
ig4iic_get_config(ig4iic_softc_t * sc)823 ig4iic_get_config(ig4iic_softc_t *sc)
824 {
825 	const struct ig4_hw *hw;
826 	uint32_t v;
827 #ifdef DEV_ACPI
828 	ACPI_HANDLE handle;
829 #endif
830 	/* Fetch default hardware config from controller */
831 	sc->cfg.version = reg_read(sc, IG4_REG_COMP_VER);
832 	sc->cfg.bus_speed = reg_read(sc, IG4_REG_CTL) & IG4_CTL_SPEED_MASK;
833 	sc->cfg.ss_scl_hcnt =
834 	    reg_read(sc, IG4_REG_SS_SCL_HCNT) & IG4_SCL_CLOCK_MASK;
835 	sc->cfg.ss_scl_lcnt =
836 	    reg_read(sc, IG4_REG_SS_SCL_LCNT) & IG4_SCL_CLOCK_MASK;
837 	sc->cfg.fs_scl_hcnt =
838 	    reg_read(sc, IG4_REG_FS_SCL_HCNT) & IG4_SCL_CLOCK_MASK;
839 	sc->cfg.fs_scl_lcnt =
840 	    reg_read(sc, IG4_REG_FS_SCL_LCNT) & IG4_SCL_CLOCK_MASK;
841 	sc->cfg.ss_sda_hold = sc->cfg.fs_sda_hold =
842 	    reg_read(sc, IG4_REG_SDA_HOLD) & IG4_SDA_TX_HOLD_MASK;
843 
844 	if (sc->cfg.bus_speed != IG4_CTL_SPEED_STD)
845 		sc->cfg.bus_speed = IG4_CTL_SPEED_FAST;
846 
847 	/* REG_COMP_PARAM1 is not documented in latest Intel specs */
848 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
849 		v = reg_read(sc, IG4_REG_COMP_PARAM1);
850 		if (IG4_PARAM1_TXFIFO_DEPTH(v) != 0)
851 			sc->cfg.txfifo_depth = IG4_PARAM1_TXFIFO_DEPTH(v);
852 		if (IG4_PARAM1_RXFIFO_DEPTH(v) != 0)
853 			sc->cfg.rxfifo_depth = IG4_PARAM1_RXFIFO_DEPTH(v);
854 	}
855 
856 	/* Override hardware config with IC_clock-based counter values */
857 	if (ig4_timings < 2 && sc->version < nitems(ig4iic_hw)) {
858 		hw = &ig4iic_hw[sc->version];
859 		sc->cfg.bus_speed = IG4_CTL_SPEED_FAST;
860 		ig4iic_clk_params(hw, IG4_CTL_SPEED_STD, &sc->cfg.ss_scl_hcnt,
861 		    &sc->cfg.ss_scl_lcnt, &sc->cfg.ss_sda_hold);
862 		ig4iic_clk_params(hw, IG4_CTL_SPEED_FAST, &sc->cfg.fs_scl_hcnt,
863 		    &sc->cfg.fs_scl_lcnt, &sc->cfg.fs_sda_hold);
864 		if (hw->txfifo_depth != 0)
865 			sc->cfg.txfifo_depth = hw->txfifo_depth;
866 		if (hw->rxfifo_depth != 0)
867 			sc->cfg.rxfifo_depth = hw->rxfifo_depth;
868 	} else if (ig4_timings == 2) {
869 		/*
870 		 * Timings of original ig4 driver:
871 		 * Program based on a 25000 Hz clock.  This is a bit of a
872 		 * hack (obviously).  The defaults are 400 and 470 for standard
873 		 * and 60 and 130 for fast.  The defaults for standard fail
874 		 * utterly (presumably cause an abort) because the clock time
875 		 * is ~18.8ms by default.  This brings it down to ~4ms.
876 		 */
877 		sc->cfg.bus_speed = IG4_CTL_SPEED_STD;
878 		sc->cfg.ss_scl_hcnt = sc->cfg.fs_scl_hcnt = 100;
879 		sc->cfg.ss_scl_lcnt = sc->cfg.fs_scl_lcnt = 125;
880 		if (sc->version == IG4_SKYLAKE)
881 			sc->cfg.ss_sda_hold = sc->cfg.fs_sda_hold = 28;
882 	}
883 
884 #ifdef DEV_ACPI
885 	/* Evaluate SSCN and FMCN ACPI methods to fetch timings */
886 	if (ig4_timings == 0 && (handle = acpi_get_handle(sc->dev)) != NULL) {
887 		ig4iic_acpi_params(handle, "SSCN", &sc->cfg.ss_scl_hcnt,
888 		    &sc->cfg.ss_scl_lcnt, &sc->cfg.ss_sda_hold);
889 		ig4iic_acpi_params(handle, "FMCN", &sc->cfg.fs_scl_hcnt,
890 		    &sc->cfg.fs_scl_lcnt, &sc->cfg.fs_sda_hold);
891 	}
892 #endif
893 
894 	if (bootverbose) {
895 		device_printf(sc->dev, "Controller parameters:\n");
896 		printf("  Speed: %s\n",
897 		    sc->cfg.bus_speed == IG4_CTL_SPEED_STD ? "Std" : "Fast");
898 		printf("  Regs:  HCNT  :LCNT  :SDAHLD\n");
899 		printf("  Std:   0x%04hx:0x%04hx:0x%04hx\n",
900 		    sc->cfg.ss_scl_hcnt, sc->cfg.ss_scl_lcnt,
901 		    sc->cfg.ss_sda_hold);
902 		printf("  Fast:  0x%04hx:0x%04hx:0x%04hx\n",
903 		    sc->cfg.fs_scl_hcnt, sc->cfg.fs_scl_lcnt,
904 		    sc->cfg.fs_sda_hold);
905 	}
906 }
907 
908 static int
ig4iic_set_config(ig4iic_softc_t * sc,bool reset)909 ig4iic_set_config(ig4iic_softc_t *sc, bool reset)
910 {
911 	uint32_t v;
912 
913 	v = reg_read(sc, IG4_REG_DEVIDLE_CTRL);
914 	if (IG4_HAS_ADDREGS(sc->version) && (v & IG4_RESTORE_REQUIRED)) {
915 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, IG4_DEVICE_IDLE | IG4_RESTORE_REQUIRED);
916 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, 0);
917 		pause("i2crst", 1);
918 		reset = true;
919 	}
920 
921 	if ((sc->version == IG4_HASWELL || sc->version == IG4_ATOM) && reset) {
922 		reg_write(sc, IG4_REG_RESETS_HSW, IG4_RESETS_ASSERT_HSW);
923 		reg_write(sc, IG4_REG_RESETS_HSW, IG4_RESETS_DEASSERT_HSW);
924 	} else if (IG4_HAS_ADDREGS(sc->version) && reset) {
925 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_ASSERT_SKL);
926 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_DEASSERT_SKL);
927 	}
928 
929 	if (sc->version == IG4_ATOM)
930 		v = reg_read(sc, IG4_REG_COMP_TYPE);
931 
932 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
933 		v = reg_read(sc, IG4_REG_COMP_PARAM1);
934 		v = reg_read(sc, IG4_REG_GENERAL);
935 		/*
936 		 * The content of IG4_REG_GENERAL is different for each
937 		 * controller version.
938 		 */
939 		if (sc->version == IG4_HASWELL &&
940 		    (v & IG4_GENERAL_SWMODE) == 0) {
941 			v |= IG4_GENERAL_SWMODE;
942 			reg_write(sc, IG4_REG_GENERAL, v);
943 			v = reg_read(sc, IG4_REG_GENERAL);
944 		}
945 	}
946 
947 	if (sc->version == IG4_HASWELL) {
948 		v = reg_read(sc, IG4_REG_SW_LTR_VALUE);
949 		v = reg_read(sc, IG4_REG_AUTO_LTR_VALUE);
950 	} else if (IG4_HAS_ADDREGS(sc->version)) {
951 		v = reg_read(sc, IG4_REG_ACTIVE_LTR_VALUE);
952 		v = reg_read(sc, IG4_REG_IDLE_LTR_VALUE);
953 	}
954 
955 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
956 		v = reg_read(sc, IG4_REG_COMP_VER);
957 		if (v < IG4_COMP_MIN_VER)
958 			return(ENXIO);
959 	}
960 
961 	if (set_controller(sc, 0)) {
962 		device_printf(sc->dev, "controller error during attach-1\n");
963 		return (ENXIO);
964 	}
965 
966 	reg_read(sc, IG4_REG_CLR_INTR);
967 	reg_write(sc, IG4_REG_INTR_MASK, 0);
968 	sc->intr_mask = 0;
969 
970 	reg_write(sc, IG4_REG_SS_SCL_HCNT, sc->cfg.ss_scl_hcnt);
971 	reg_write(sc, IG4_REG_SS_SCL_LCNT, sc->cfg.ss_scl_lcnt);
972 	reg_write(sc, IG4_REG_FS_SCL_HCNT, sc->cfg.fs_scl_hcnt);
973 	reg_write(sc, IG4_REG_FS_SCL_LCNT, sc->cfg.fs_scl_lcnt);
974 	reg_write(sc, IG4_REG_SDA_HOLD,
975 	    (sc->cfg.bus_speed  & IG4_CTL_SPEED_MASK) == IG4_CTL_SPEED_STD ?
976 	      sc->cfg.ss_sda_hold : sc->cfg.fs_sda_hold);
977 
978 	reg_write(sc, IG4_REG_RX_TL, 0);
979 	reg_write(sc, IG4_REG_TX_TL, 0);
980 
981 	reg_write(sc, IG4_REG_CTL,
982 		  IG4_CTL_MASTER |
983 		  IG4_CTL_SLAVE_DISABLE |
984 		  IG4_CTL_RESTARTEN |
985 		  (sc->cfg.bus_speed & IG4_CTL_SPEED_MASK));
986 
987 	/* Force setting of the target address on the next transfer */
988 	sc->slave_valid = false;
989 
990 	return (0);
991 }
992 
993 static void
ig4iic_get_fifo(ig4iic_softc_t * sc)994 ig4iic_get_fifo(ig4iic_softc_t *sc)
995 {
996 	uint32_t v;
997 
998 	/*
999 	 * Hardware does not allow FIFO Threshold Levels value to be set larger
1000 	 * than the depth of the buffer.  If an attempt is made to do that, the
1001 	 * actual value set will be the maximum depth of the buffer.
1002 	 */
1003 	if (sc->cfg.txfifo_depth == 0) {
1004 		v = reg_read(sc, IG4_REG_TX_TL);
1005 		reg_write(sc, IG4_REG_TX_TL, v | IG4_FIFO_MASK);
1006 		sc->cfg.txfifo_depth =
1007 		    (reg_read(sc, IG4_REG_TX_TL) & IG4_FIFO_MASK) + 1;
1008 		reg_write(sc, IG4_REG_TX_TL, v);
1009 	}
1010 	if (sc->cfg.rxfifo_depth == 0) {
1011 		v = reg_read(sc, IG4_REG_RX_TL);
1012 		reg_write(sc, IG4_REG_RX_TL, v | IG4_FIFO_MASK);
1013 		sc->cfg.rxfifo_depth =
1014 		    (reg_read(sc, IG4_REG_RX_TL) & IG4_FIFO_MASK) + 1;
1015 		reg_write(sc, IG4_REG_RX_TL, v);
1016 	}
1017 	if (bootverbose) {
1018 		printf("  FIFO:  RX:0x%04x: TX:0x%04x\n",
1019 		    sc->cfg.rxfifo_depth, sc->cfg.txfifo_depth);
1020 	}
1021 }
1022 
1023 /*
1024  * Called from ig4iic_pci_attach/detach()
1025  */
1026 int
ig4iic_attach(ig4iic_softc_t * sc)1027 ig4iic_attach(ig4iic_softc_t *sc)
1028 {
1029 	int error;
1030 
1031 	mtx_init(&sc->io_lock, "IG4 I/O lock", NULL, MTX_SPIN);
1032 	sx_init(&sc->call_lock, "IG4 call lock");
1033 
1034 	ig4iic_get_config(sc);
1035 
1036 	error = ig4iic_set_config(sc, IG4_HAS_ADDREGS(sc->version));
1037 	if (error)
1038 		goto done;
1039 	ig4iic_get_fifo(sc);
1040 
1041 	sc->iicbus = device_add_child(sc->dev, "iicbus", -1);
1042 	if (sc->iicbus == NULL) {
1043 		device_printf(sc->dev, "iicbus driver not found\n");
1044 		error = ENXIO;
1045 		goto done;
1046 	}
1047 
1048 	if (set_controller(sc, IG4_I2C_ENABLE)) {
1049 		device_printf(sc->dev, "controller error during attach-2\n");
1050 		error = ENXIO;
1051 		goto done;
1052 	}
1053 	if (set_controller(sc, 0)) {
1054 		device_printf(sc->dev, "controller error during attach-3\n");
1055 		error = ENXIO;
1056 		goto done;
1057 	}
1058 	error = bus_setup_intr(sc->dev, sc->intr_res, INTR_TYPE_MISC | INTR_MPSAFE,
1059 			       ig4iic_intr, NULL, sc, &sc->intr_handle);
1060 	if (error) {
1061 		device_printf(sc->dev,
1062 			      "Unable to setup irq: error %d\n", error);
1063 	}
1064 
1065 	error = bus_generic_attach(sc->dev);
1066 	if (error) {
1067 		device_printf(sc->dev,
1068 			      "failed to attach child: error %d\n", error);
1069 	}
1070 
1071 done:
1072 	return (error);
1073 }
1074 
1075 int
ig4iic_detach(ig4iic_softc_t * sc)1076 ig4iic_detach(ig4iic_softc_t *sc)
1077 {
1078 	int error;
1079 
1080 	if (device_is_attached(sc->dev)) {
1081 		error = bus_generic_detach(sc->dev);
1082 		if (error)
1083 			return (error);
1084 	}
1085 	if (sc->iicbus)
1086 		device_delete_child(sc->dev, sc->iicbus);
1087 	if (sc->intr_handle)
1088 		bus_teardown_intr(sc->dev, sc->intr_res, sc->intr_handle);
1089 
1090 	sx_xlock(&sc->call_lock);
1091 
1092 	sc->iicbus = NULL;
1093 	sc->intr_handle = NULL;
1094 	reg_write(sc, IG4_REG_INTR_MASK, 0);
1095 	set_controller(sc, 0);
1096 
1097 	sx_xunlock(&sc->call_lock);
1098 
1099 	mtx_destroy(&sc->io_lock);
1100 	sx_destroy(&sc->call_lock);
1101 
1102 	return (0);
1103 }
1104 
1105 int
ig4iic_suspend(ig4iic_softc_t * sc)1106 ig4iic_suspend(ig4iic_softc_t *sc)
1107 {
1108 	int error;
1109 
1110 	/* suspend all children */
1111 	error = bus_generic_suspend(sc->dev);
1112 
1113 	sx_xlock(&sc->call_lock);
1114 	set_controller(sc, 0);
1115 	if (IG4_HAS_ADDREGS(sc->version)) {
1116 		/*
1117 		 * Place the device in the idle state, just to be safe
1118 		 */
1119 		reg_write(sc, IG4_REG_DEVIDLE_CTRL, IG4_DEVICE_IDLE);
1120 		/*
1121 		 * Controller can become dysfunctional if I2C lines are pulled
1122 		 * down when suspend procedure turns off power to I2C device.
1123 		 * Place device in the reset state to avoid this.
1124 		 */
1125 		reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_ASSERT_SKL);
1126 	}
1127 	sx_xunlock(&sc->call_lock);
1128 
1129 	return (error);
1130 }
1131 
ig4iic_resume(ig4iic_softc_t * sc)1132 int ig4iic_resume(ig4iic_softc_t *sc)
1133 {
1134 	int error;
1135 
1136 	sx_xlock(&sc->call_lock);
1137 	if (ig4iic_set_config(sc, IG4_HAS_ADDREGS(sc->version)))
1138 		device_printf(sc->dev, "controller error during resume\n");
1139 	sx_xunlock(&sc->call_lock);
1140 
1141 	error = bus_generic_resume(sc->dev);
1142 
1143 	return (error);
1144 }
1145 
1146 /*
1147  * Interrupt Operation, see ig4_var.h for locking semantics.
1148  */
1149 static int
ig4iic_intr(void * cookie)1150 ig4iic_intr(void *cookie)
1151 {
1152 	ig4iic_softc_t *sc = cookie;
1153 	int retval = FILTER_STRAY;
1154 
1155 	mtx_lock_spin(&sc->io_lock);
1156 	/* Ignore stray interrupts */
1157 	if (sc->intr_mask != 0 && reg_read(sc, IG4_REG_INTR_STAT) != 0) {
1158 		/* Interrupt bits are cleared in wait_intr() loop */
1159 		ig4iic_set_intr_mask(sc, 0);
1160 		wakeup(sc);
1161 		retval = FILTER_HANDLED;
1162 	}
1163 	mtx_unlock_spin(&sc->io_lock);
1164 
1165 	return (retval);
1166 }
1167 
1168 #define REGDUMP(sc, reg)	\
1169 	device_printf(sc->dev, "  %-23s %08x\n", #reg, reg_read(sc, reg))
1170 
1171 static void
ig4iic_dump(ig4iic_softc_t * sc)1172 ig4iic_dump(ig4iic_softc_t *sc)
1173 {
1174 	device_printf(sc->dev, "ig4iic register dump:\n");
1175 	REGDUMP(sc, IG4_REG_CTL);
1176 	REGDUMP(sc, IG4_REG_TAR_ADD);
1177 	REGDUMP(sc, IG4_REG_SS_SCL_HCNT);
1178 	REGDUMP(sc, IG4_REG_SS_SCL_LCNT);
1179 	REGDUMP(sc, IG4_REG_FS_SCL_HCNT);
1180 	REGDUMP(sc, IG4_REG_FS_SCL_LCNT);
1181 	REGDUMP(sc, IG4_REG_INTR_STAT);
1182 	REGDUMP(sc, IG4_REG_INTR_MASK);
1183 	REGDUMP(sc, IG4_REG_RAW_INTR_STAT);
1184 	REGDUMP(sc, IG4_REG_RX_TL);
1185 	REGDUMP(sc, IG4_REG_TX_TL);
1186 	REGDUMP(sc, IG4_REG_I2C_EN);
1187 	REGDUMP(sc, IG4_REG_I2C_STA);
1188 	REGDUMP(sc, IG4_REG_TXFLR);
1189 	REGDUMP(sc, IG4_REG_RXFLR);
1190 	REGDUMP(sc, IG4_REG_SDA_HOLD);
1191 	REGDUMP(sc, IG4_REG_TX_ABRT_SOURCE);
1192 	REGDUMP(sc, IG4_REG_SLV_DATA_NACK);
1193 	REGDUMP(sc, IG4_REG_DMA_CTRL);
1194 	REGDUMP(sc, IG4_REG_DMA_TDLR);
1195 	REGDUMP(sc, IG4_REG_DMA_RDLR);
1196 	REGDUMP(sc, IG4_REG_SDA_SETUP);
1197 	REGDUMP(sc, IG4_REG_ENABLE_STATUS);
1198 	REGDUMP(sc, IG4_REG_COMP_PARAM1);
1199 	REGDUMP(sc, IG4_REG_COMP_VER);
1200 	if (sc->version == IG4_ATOM) {
1201 		REGDUMP(sc, IG4_REG_COMP_TYPE);
1202 		REGDUMP(sc, IG4_REG_CLK_PARMS);
1203 	}
1204 	if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
1205 		REGDUMP(sc, IG4_REG_RESETS_HSW);
1206 		REGDUMP(sc, IG4_REG_GENERAL);
1207 	} else if (sc->version == IG4_SKYLAKE) {
1208 		REGDUMP(sc, IG4_REG_RESETS_SKL);
1209 	}
1210 	if (sc->version == IG4_HASWELL) {
1211 		REGDUMP(sc, IG4_REG_SW_LTR_VALUE);
1212 		REGDUMP(sc, IG4_REG_AUTO_LTR_VALUE);
1213 	} else if (IG4_HAS_ADDREGS(sc->version)) {
1214 		REGDUMP(sc, IG4_REG_ACTIVE_LTR_VALUE);
1215 		REGDUMP(sc, IG4_REG_IDLE_LTR_VALUE);
1216 	}
1217 }
1218 #undef REGDUMP
1219 
1220 DRIVER_MODULE(iicbus, ig4iic, iicbus_driver, NULL, NULL);
1221 #ifdef DEV_ACPI
1222 DRIVER_MODULE(acpi_iicbus, ig4iic, acpi_iicbus_driver, NULL, NULL);
1223 #endif
1224 MODULE_DEPEND(ig4iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
1225 MODULE_VERSION(ig4iic, 1);
1226