xref: /openbmc/linux/drivers/char/tpm/tpm_tis_core.c (revision 82003e04)
1 /*
2  * Copyright (C) 2005, 2006 IBM Corporation
3  * Copyright (C) 2014, 2015 Intel Corporation
4  *
5  * Authors:
6  * Leendert van Doorn <leendert@watson.ibm.com>
7  * Kylene Hall <kjhall@us.ibm.com>
8  *
9  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
10  *
11  * Device driver for TCG/TCPA TPM (trusted platform module).
12  * Specifications at www.trustedcomputinggroup.org
13  *
14  * This device driver implements the TPM interface as defined in
15  * the TCG TPM Interface Spec version 1.2, revision 1.0.
16  *
17  * This program is free software; you can redistribute it and/or
18  * modify it under the terms of the GNU General Public License as
19  * published by the Free Software Foundation, version 2 of the
20  * License.
21  */
22 #include <linux/init.h>
23 #include <linux/module.h>
24 #include <linux/moduleparam.h>
25 #include <linux/pnp.h>
26 #include <linux/slab.h>
27 #include <linux/interrupt.h>
28 #include <linux/wait.h>
29 #include <linux/acpi.h>
30 #include <linux/freezer.h>
31 #include "tpm.h"
32 #include "tpm_tis_core.h"
33 
34 /* Before we attempt to access the TPM we must see that the valid bit is set.
35  * The specification says that this bit is 0 at reset and remains 0 until the
36  * 'TPM has gone through its self test and initialization and has established
37  * correct values in the other bits.'
38  */
39 static int wait_startup(struct tpm_chip *chip, int l)
40 {
41 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
42 	unsigned long stop = jiffies + chip->timeout_a;
43 
44 	do {
45 		int rc;
46 		u8 access;
47 
48 		rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
49 		if (rc < 0)
50 			return rc;
51 
52 		if (access & TPM_ACCESS_VALID)
53 			return 0;
54 		msleep(TPM_TIMEOUT);
55 	} while (time_before(jiffies, stop));
56 	return -1;
57 }
58 
59 static int check_locality(struct tpm_chip *chip, int l)
60 {
61 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
62 	int rc;
63 	u8 access;
64 
65 	rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
66 	if (rc < 0)
67 		return rc;
68 
69 	if ((access & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
70 	    (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
71 		return priv->locality = l;
72 
73 	return -1;
74 }
75 
76 static void release_locality(struct tpm_chip *chip, int l, int force)
77 {
78 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
79 	int rc;
80 	u8 access;
81 
82 	rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
83 	if (rc < 0)
84 		return;
85 
86 	if (force || (access &
87 		      (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) ==
88 	    (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID))
89 		tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
90 
91 }
92 
93 static int request_locality(struct tpm_chip *chip, int l)
94 {
95 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
96 	unsigned long stop, timeout;
97 	long rc;
98 
99 	if (check_locality(chip, l) >= 0)
100 		return l;
101 
102 	rc = tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_REQUEST_USE);
103 	if (rc < 0)
104 		return rc;
105 
106 	stop = jiffies + chip->timeout_a;
107 
108 	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
109 again:
110 		timeout = stop - jiffies;
111 		if ((long)timeout <= 0)
112 			return -1;
113 		rc = wait_event_interruptible_timeout(priv->int_queue,
114 						      (check_locality
115 						       (chip, l) >= 0),
116 						      timeout);
117 		if (rc > 0)
118 			return l;
119 		if (rc == -ERESTARTSYS && freezing(current)) {
120 			clear_thread_flag(TIF_SIGPENDING);
121 			goto again;
122 		}
123 	} else {
124 		/* wait for burstcount */
125 		do {
126 			if (check_locality(chip, l) >= 0)
127 				return l;
128 			msleep(TPM_TIMEOUT);
129 		} while (time_before(jiffies, stop));
130 	}
131 	return -1;
132 }
133 
134 static u8 tpm_tis_status(struct tpm_chip *chip)
135 {
136 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
137 	int rc;
138 	u8 status;
139 
140 	rc = tpm_tis_read8(priv, TPM_STS(priv->locality), &status);
141 	if (rc < 0)
142 		return 0;
143 
144 	return status;
145 }
146 
147 static void tpm_tis_ready(struct tpm_chip *chip)
148 {
149 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
150 
151 	/* this causes the current command to be aborted */
152 	tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_COMMAND_READY);
153 }
154 
155 static int get_burstcount(struct tpm_chip *chip)
156 {
157 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
158 	unsigned long stop;
159 	int burstcnt, rc;
160 	u32 value;
161 
162 	/* wait for burstcount */
163 	/* which timeout value, spec has 2 answers (c & d) */
164 	stop = jiffies + chip->timeout_d;
165 	do {
166 		rc = tpm_tis_read32(priv, TPM_STS(priv->locality), &value);
167 		if (rc < 0)
168 			return rc;
169 
170 		burstcnt = (value >> 8) & 0xFFFF;
171 		if (burstcnt)
172 			return burstcnt;
173 		msleep(TPM_TIMEOUT);
174 	} while (time_before(jiffies, stop));
175 	return -EBUSY;
176 }
177 
178 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
179 {
180 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
181 	int size = 0, burstcnt, rc;
182 
183 	while (size < count) {
184 		rc = wait_for_tpm_stat(chip,
185 				 TPM_STS_DATA_AVAIL | TPM_STS_VALID,
186 				 chip->timeout_c,
187 				 &priv->read_queue, true);
188 		if (rc < 0)
189 			return rc;
190 		burstcnt = get_burstcount(chip);
191 		if (burstcnt < 0) {
192 			dev_err(&chip->dev, "Unable to read burstcount\n");
193 			return burstcnt;
194 		}
195 		burstcnt = min_t(int, burstcnt, count - size);
196 
197 		rc = tpm_tis_read_bytes(priv, TPM_DATA_FIFO(priv->locality),
198 					burstcnt, buf + size);
199 		if (rc < 0)
200 			return rc;
201 
202 		size += burstcnt;
203 	}
204 	return size;
205 }
206 
207 static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
208 {
209 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
210 	int size = 0;
211 	int expected, status;
212 
213 	if (count < TPM_HEADER_SIZE) {
214 		size = -EIO;
215 		goto out;
216 	}
217 
218 	size = recv_data(chip, buf, TPM_HEADER_SIZE);
219 	/* read first 10 bytes, including tag, paramsize, and result */
220 	if (size < TPM_HEADER_SIZE) {
221 		dev_err(&chip->dev, "Unable to read header\n");
222 		goto out;
223 	}
224 
225 	expected = be32_to_cpu(*(__be32 *) (buf + 2));
226 	if (expected > count) {
227 		size = -EIO;
228 		goto out;
229 	}
230 
231 	size += recv_data(chip, &buf[TPM_HEADER_SIZE],
232 			  expected - TPM_HEADER_SIZE);
233 	if (size < expected) {
234 		dev_err(&chip->dev, "Unable to read remainder of result\n");
235 		size = -ETIME;
236 		goto out;
237 	}
238 
239 	if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
240 				&priv->int_queue, false) < 0) {
241 		size = -ETIME;
242 		goto out;
243 	}
244 	status = tpm_tis_status(chip);
245 	if (status & TPM_STS_DATA_AVAIL) {	/* retry? */
246 		dev_err(&chip->dev, "Error left over data\n");
247 		size = -EIO;
248 		goto out;
249 	}
250 
251 out:
252 	tpm_tis_ready(chip);
253 	release_locality(chip, priv->locality, 0);
254 	return size;
255 }
256 
257 /*
258  * If interrupts are used (signaled by an irq set in the vendor structure)
259  * tpm.c can skip polling for the data to be available as the interrupt is
260  * waited for here
261  */
262 static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
263 {
264 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
265 	int rc, status, burstcnt;
266 	size_t count = 0;
267 	bool itpm = priv->flags & TPM_TIS_ITPM_POSSIBLE;
268 
269 	if (request_locality(chip, 0) < 0)
270 		return -EBUSY;
271 
272 	status = tpm_tis_status(chip);
273 	if ((status & TPM_STS_COMMAND_READY) == 0) {
274 		tpm_tis_ready(chip);
275 		if (wait_for_tpm_stat
276 		    (chip, TPM_STS_COMMAND_READY, chip->timeout_b,
277 		     &priv->int_queue, false) < 0) {
278 			rc = -ETIME;
279 			goto out_err;
280 		}
281 	}
282 
283 	while (count < len - 1) {
284 		burstcnt = get_burstcount(chip);
285 		if (burstcnt < 0) {
286 			dev_err(&chip->dev, "Unable to read burstcount\n");
287 			rc = burstcnt;
288 			goto out_err;
289 		}
290 		burstcnt = min_t(int, burstcnt, len - count - 1);
291 		rc = tpm_tis_write_bytes(priv, TPM_DATA_FIFO(priv->locality),
292 					 burstcnt, buf + count);
293 		if (rc < 0)
294 			goto out_err;
295 
296 		count += burstcnt;
297 
298 		if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
299 					&priv->int_queue, false) < 0) {
300 			rc = -ETIME;
301 			goto out_err;
302 		}
303 		status = tpm_tis_status(chip);
304 		if (!itpm && (status & TPM_STS_DATA_EXPECT) == 0) {
305 			rc = -EIO;
306 			goto out_err;
307 		}
308 	}
309 
310 	/* write last byte */
311 	rc = tpm_tis_write8(priv, TPM_DATA_FIFO(priv->locality), buf[count]);
312 	if (rc < 0)
313 		goto out_err;
314 
315 	if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
316 				&priv->int_queue, false) < 0) {
317 		rc = -ETIME;
318 		goto out_err;
319 	}
320 	status = tpm_tis_status(chip);
321 	if (!itpm && (status & TPM_STS_DATA_EXPECT) != 0) {
322 		rc = -EIO;
323 		goto out_err;
324 	}
325 
326 	return 0;
327 
328 out_err:
329 	tpm_tis_ready(chip);
330 	release_locality(chip, priv->locality, 0);
331 	return rc;
332 }
333 
334 static void disable_interrupts(struct tpm_chip *chip)
335 {
336 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
337 	u32 intmask;
338 	int rc;
339 
340 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
341 	if (rc < 0)
342 		intmask = 0;
343 
344 	intmask &= ~TPM_GLOBAL_INT_ENABLE;
345 	rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
346 
347 	devm_free_irq(chip->dev.parent, priv->irq, chip);
348 	priv->irq = 0;
349 	chip->flags &= ~TPM_CHIP_FLAG_IRQ;
350 }
351 
352 /*
353  * If interrupts are used (signaled by an irq set in the vendor structure)
354  * tpm.c can skip polling for the data to be available as the interrupt is
355  * waited for here
356  */
357 static int tpm_tis_send_main(struct tpm_chip *chip, u8 *buf, size_t len)
358 {
359 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
360 	int rc;
361 	u32 ordinal;
362 	unsigned long dur;
363 
364 	rc = tpm_tis_send_data(chip, buf, len);
365 	if (rc < 0)
366 		return rc;
367 
368 	/* go and do it */
369 	rc = tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO);
370 	if (rc < 0)
371 		goto out_err;
372 
373 	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
374 		ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
375 
376 		if (chip->flags & TPM_CHIP_FLAG_TPM2)
377 			dur = tpm2_calc_ordinal_duration(chip, ordinal);
378 		else
379 			dur = tpm_calc_ordinal_duration(chip, ordinal);
380 
381 		if (wait_for_tpm_stat
382 		    (chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID, dur,
383 		     &priv->read_queue, false) < 0) {
384 			rc = -ETIME;
385 			goto out_err;
386 		}
387 	}
388 	return len;
389 out_err:
390 	tpm_tis_ready(chip);
391 	release_locality(chip, priv->locality, 0);
392 	return rc;
393 }
394 
395 static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
396 {
397 	int rc, irq;
398 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
399 
400 	if (!(chip->flags & TPM_CHIP_FLAG_IRQ) || priv->irq_tested)
401 		return tpm_tis_send_main(chip, buf, len);
402 
403 	/* Verify receipt of the expected IRQ */
404 	irq = priv->irq;
405 	priv->irq = 0;
406 	chip->flags &= ~TPM_CHIP_FLAG_IRQ;
407 	rc = tpm_tis_send_main(chip, buf, len);
408 	priv->irq = irq;
409 	chip->flags |= TPM_CHIP_FLAG_IRQ;
410 	if (!priv->irq_tested)
411 		msleep(1);
412 	if (!priv->irq_tested)
413 		disable_interrupts(chip);
414 	priv->irq_tested = true;
415 	return rc;
416 }
417 
418 struct tis_vendor_timeout_override {
419 	u32 did_vid;
420 	unsigned long timeout_us[4];
421 };
422 
423 static const struct tis_vendor_timeout_override vendor_timeout_overrides[] = {
424 	/* Atmel 3204 */
425 	{ 0x32041114, { (TIS_SHORT_TIMEOUT*1000), (TIS_LONG_TIMEOUT*1000),
426 			(TIS_SHORT_TIMEOUT*1000), (TIS_SHORT_TIMEOUT*1000) } },
427 };
428 
429 static bool tpm_tis_update_timeouts(struct tpm_chip *chip,
430 				    unsigned long *timeout_cap)
431 {
432 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
433 	int i, rc;
434 	u32 did_vid;
435 
436 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &did_vid);
437 	if (rc < 0)
438 		return rc;
439 
440 	for (i = 0; i != ARRAY_SIZE(vendor_timeout_overrides); i++) {
441 		if (vendor_timeout_overrides[i].did_vid != did_vid)
442 			continue;
443 		memcpy(timeout_cap, vendor_timeout_overrides[i].timeout_us,
444 		       sizeof(vendor_timeout_overrides[i].timeout_us));
445 		return true;
446 	}
447 
448 	return false;
449 }
450 
451 /*
452  * Early probing for iTPM with STS_DATA_EXPECT flaw.
453  * Try sending command without itpm flag set and if that
454  * fails, repeat with itpm flag set.
455  */
456 static int probe_itpm(struct tpm_chip *chip)
457 {
458 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
459 	int rc = 0;
460 	u8 cmd_getticks[] = {
461 		0x00, 0xc1, 0x00, 0x00, 0x00, 0x0a,
462 		0x00, 0x00, 0x00, 0xf1
463 	};
464 	size_t len = sizeof(cmd_getticks);
465 	u16 vendor;
466 
467 	rc = tpm_tis_read16(priv, TPM_DID_VID(0), &vendor);
468 	if (rc < 0)
469 		return rc;
470 
471 	/* probe only iTPMS */
472 	if (vendor != TPM_VID_INTEL)
473 		return 0;
474 
475 	rc = tpm_tis_send_data(chip, cmd_getticks, len);
476 	if (rc == 0)
477 		goto out;
478 
479 	tpm_tis_ready(chip);
480 	release_locality(chip, priv->locality, 0);
481 
482 	rc = tpm_tis_send_data(chip, cmd_getticks, len);
483 	if (rc == 0) {
484 		dev_info(&chip->dev, "Detected an iTPM.\n");
485 		rc = 1;
486 	} else
487 		rc = -EFAULT;
488 
489 out:
490 	tpm_tis_ready(chip);
491 	release_locality(chip, priv->locality, 0);
492 
493 	return rc;
494 }
495 
496 static bool tpm_tis_req_canceled(struct tpm_chip *chip, u8 status)
497 {
498 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
499 
500 	switch (priv->manufacturer_id) {
501 	case TPM_VID_WINBOND:
502 		return ((status == TPM_STS_VALID) ||
503 			(status == (TPM_STS_VALID | TPM_STS_COMMAND_READY)));
504 	case TPM_VID_STM:
505 		return (status == (TPM_STS_VALID | TPM_STS_COMMAND_READY));
506 	default:
507 		return (status == TPM_STS_COMMAND_READY);
508 	}
509 }
510 
511 static irqreturn_t tis_int_handler(int dummy, void *dev_id)
512 {
513 	struct tpm_chip *chip = dev_id;
514 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
515 	u32 interrupt;
516 	int i, rc;
517 
518 	rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
519 	if (rc < 0)
520 		return IRQ_NONE;
521 
522 	if (interrupt == 0)
523 		return IRQ_NONE;
524 
525 	priv->irq_tested = true;
526 	if (interrupt & TPM_INTF_DATA_AVAIL_INT)
527 		wake_up_interruptible(&priv->read_queue);
528 	if (interrupt & TPM_INTF_LOCALITY_CHANGE_INT)
529 		for (i = 0; i < 5; i++)
530 			if (check_locality(chip, i) >= 0)
531 				break;
532 	if (interrupt &
533 	    (TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_STS_VALID_INT |
534 	     TPM_INTF_CMD_READY_INT))
535 		wake_up_interruptible(&priv->int_queue);
536 
537 	/* Clear interrupts handled with TPM_EOI */
538 	rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), interrupt);
539 	if (rc < 0)
540 		return IRQ_NONE;
541 
542 	tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
543 	return IRQ_HANDLED;
544 }
545 
546 static int tpm_tis_gen_interrupt(struct tpm_chip *chip)
547 {
548 	const char *desc = "attempting to generate an interrupt";
549 	u32 cap2;
550 	cap_t cap;
551 
552 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
553 		return tpm2_get_tpm_pt(chip, 0x100, &cap2, desc);
554 	else
555 		return tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc);
556 }
557 
558 /* Register the IRQ and issue a command that will cause an interrupt. If an
559  * irq is seen then leave the chip setup for IRQ operation, otherwise reverse
560  * everything and leave in polling mode. Returns 0 on success.
561  */
562 static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
563 				    int flags, int irq)
564 {
565 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
566 	u8 original_int_vec;
567 	int rc;
568 	u32 int_status;
569 
570 	if (devm_request_irq(chip->dev.parent, irq, tis_int_handler, flags,
571 			     dev_name(&chip->dev), chip) != 0) {
572 		dev_info(&chip->dev, "Unable to request irq: %d for probe\n",
573 			 irq);
574 		return -1;
575 	}
576 	priv->irq = irq;
577 
578 	rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
579 			   &original_int_vec);
580 	if (rc < 0)
581 		return rc;
582 
583 	rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), irq);
584 	if (rc < 0)
585 		return rc;
586 
587 	rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &int_status);
588 	if (rc < 0)
589 		return rc;
590 
591 	/* Clear all existing */
592 	rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), int_status);
593 	if (rc < 0)
594 		return rc;
595 
596 	/* Turn on */
597 	rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality),
598 			     intmask | TPM_GLOBAL_INT_ENABLE);
599 	if (rc < 0)
600 		return rc;
601 
602 	priv->irq_tested = false;
603 
604 	/* Generate an interrupt by having the core call through to
605 	 * tpm_tis_send
606 	 */
607 	rc = tpm_tis_gen_interrupt(chip);
608 	if (rc < 0)
609 		return rc;
610 
611 	/* tpm_tis_send will either confirm the interrupt is working or it
612 	 * will call disable_irq which undoes all of the above.
613 	 */
614 	if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
615 		rc = tpm_tis_write8(priv, original_int_vec,
616 				TPM_INT_VECTOR(priv->locality));
617 		if (rc < 0)
618 			return rc;
619 
620 		return 1;
621 	}
622 
623 	return 0;
624 }
625 
626 /* Try to find the IRQ the TPM is using. This is for legacy x86 systems that
627  * do not have ACPI/etc. We typically expect the interrupt to be declared if
628  * present.
629  */
630 static void tpm_tis_probe_irq(struct tpm_chip *chip, u32 intmask)
631 {
632 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
633 	u8 original_int_vec;
634 	int i, rc;
635 
636 	rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
637 			   &original_int_vec);
638 	if (rc < 0)
639 		return;
640 
641 	if (!original_int_vec) {
642 		if (IS_ENABLED(CONFIG_X86))
643 			for (i = 3; i <= 15; i++)
644 				if (!tpm_tis_probe_irq_single(chip, intmask, 0,
645 							      i))
646 					return;
647 	} else if (!tpm_tis_probe_irq_single(chip, intmask, 0,
648 					     original_int_vec))
649 		return;
650 }
651 
652 void tpm_tis_remove(struct tpm_chip *chip)
653 {
654 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
655 	u32 reg = TPM_INT_ENABLE(priv->locality);
656 	u32 interrupt;
657 	int rc;
658 
659 	rc = tpm_tis_read32(priv, reg, &interrupt);
660 	if (rc < 0)
661 		interrupt = 0;
662 
663 	tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);
664 	release_locality(chip, priv->locality, 1);
665 }
666 EXPORT_SYMBOL_GPL(tpm_tis_remove);
667 
668 static const struct tpm_class_ops tpm_tis = {
669 	.flags = TPM_OPS_AUTO_STARTUP,
670 	.status = tpm_tis_status,
671 	.recv = tpm_tis_recv,
672 	.send = tpm_tis_send,
673 	.cancel = tpm_tis_ready,
674 	.update_timeouts = tpm_tis_update_timeouts,
675 	.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
676 	.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
677 	.req_canceled = tpm_tis_req_canceled,
678 };
679 
680 int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
681 		      const struct tpm_tis_phy_ops *phy_ops,
682 		      acpi_handle acpi_dev_handle)
683 {
684 	u32 vendor, intfcaps, intmask;
685 	u8 rid;
686 	int rc, probe;
687 	struct tpm_chip *chip;
688 
689 	chip = tpmm_chip_alloc(dev, &tpm_tis);
690 	if (IS_ERR(chip))
691 		return PTR_ERR(chip);
692 
693 #ifdef CONFIG_ACPI
694 	chip->acpi_dev_handle = acpi_dev_handle;
695 #endif
696 
697 	/* Maximum timeouts */
698 	chip->timeout_a = msecs_to_jiffies(TIS_TIMEOUT_A_MAX);
699 	chip->timeout_b = msecs_to_jiffies(TIS_TIMEOUT_B_MAX);
700 	chip->timeout_c = msecs_to_jiffies(TIS_TIMEOUT_C_MAX);
701 	chip->timeout_d = msecs_to_jiffies(TIS_TIMEOUT_D_MAX);
702 	priv->phy_ops = phy_ops;
703 	dev_set_drvdata(&chip->dev, priv);
704 
705 	if (wait_startup(chip, 0) != 0) {
706 		rc = -ENODEV;
707 		goto out_err;
708 	}
709 
710 	/* Take control of the TPM's interrupt hardware and shut it off */
711 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
712 	if (rc < 0)
713 		goto out_err;
714 
715 	intmask |= TPM_INTF_CMD_READY_INT | TPM_INTF_LOCALITY_CHANGE_INT |
716 		   TPM_INTF_DATA_AVAIL_INT | TPM_INTF_STS_VALID_INT;
717 	intmask &= ~TPM_GLOBAL_INT_ENABLE;
718 	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
719 
720 	if (request_locality(chip, 0) != 0) {
721 		rc = -ENODEV;
722 		goto out_err;
723 	}
724 
725 	rc = tpm2_probe(chip);
726 	if (rc)
727 		goto out_err;
728 
729 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &vendor);
730 	if (rc < 0)
731 		goto out_err;
732 
733 	priv->manufacturer_id = vendor;
734 
735 	rc = tpm_tis_read8(priv, TPM_RID(0), &rid);
736 	if (rc < 0)
737 		goto out_err;
738 
739 	dev_info(dev, "%s TPM (device-id 0x%X, rev-id %d)\n",
740 		 (chip->flags & TPM_CHIP_FLAG_TPM2) ? "2.0" : "1.2",
741 		 vendor >> 16, rid);
742 
743 	if (!(priv->flags & TPM_TIS_ITPM_POSSIBLE)) {
744 		probe = probe_itpm(chip);
745 		if (probe < 0) {
746 			rc = -ENODEV;
747 			goto out_err;
748 		}
749 
750 		if (!!probe)
751 			priv->flags |= TPM_TIS_ITPM_POSSIBLE;
752 	}
753 
754 	/* Figure out the capabilities */
755 	rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
756 	if (rc < 0)
757 		goto out_err;
758 
759 	dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
760 		intfcaps);
761 	if (intfcaps & TPM_INTF_BURST_COUNT_STATIC)
762 		dev_dbg(dev, "\tBurst Count Static\n");
763 	if (intfcaps & TPM_INTF_CMD_READY_INT)
764 		dev_dbg(dev, "\tCommand Ready Int Support\n");
765 	if (intfcaps & TPM_INTF_INT_EDGE_FALLING)
766 		dev_dbg(dev, "\tInterrupt Edge Falling\n");
767 	if (intfcaps & TPM_INTF_INT_EDGE_RISING)
768 		dev_dbg(dev, "\tInterrupt Edge Rising\n");
769 	if (intfcaps & TPM_INTF_INT_LEVEL_LOW)
770 		dev_dbg(dev, "\tInterrupt Level Low\n");
771 	if (intfcaps & TPM_INTF_INT_LEVEL_HIGH)
772 		dev_dbg(dev, "\tInterrupt Level High\n");
773 	if (intfcaps & TPM_INTF_LOCALITY_CHANGE_INT)
774 		dev_dbg(dev, "\tLocality Change Int Support\n");
775 	if (intfcaps & TPM_INTF_STS_VALID_INT)
776 		dev_dbg(dev, "\tSts Valid Int Support\n");
777 	if (intfcaps & TPM_INTF_DATA_AVAIL_INT)
778 		dev_dbg(dev, "\tData Avail Int Support\n");
779 
780 	/* INTERRUPT Setup */
781 	init_waitqueue_head(&priv->read_queue);
782 	init_waitqueue_head(&priv->int_queue);
783 	if (irq != -1) {
784 		/* Before doing irq testing issue a command to the TPM in polling mode
785 		 * to make sure it works. May as well use that command to set the
786 		 * proper timeouts for the driver.
787 		 */
788 		if (tpm_get_timeouts(chip)) {
789 			dev_err(dev, "Could not get TPM timeouts and durations\n");
790 			rc = -ENODEV;
791 			goto out_err;
792 		}
793 
794 		if (irq) {
795 			tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
796 						 irq);
797 			if (!(chip->flags & TPM_CHIP_FLAG_IRQ))
798 				dev_err(&chip->dev, FW_BUG
799 					"TPM interrupt not working, polling instead\n");
800 		} else {
801 			tpm_tis_probe_irq(chip, intmask);
802 		}
803 	}
804 
805 	return tpm_chip_register(chip);
806 out_err:
807 	tpm_tis_remove(chip);
808 	return rc;
809 }
810 EXPORT_SYMBOL_GPL(tpm_tis_core_init);
811 
812 #ifdef CONFIG_PM_SLEEP
813 static void tpm_tis_reenable_interrupts(struct tpm_chip *chip)
814 {
815 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
816 	u32 intmask;
817 	int rc;
818 
819 	/* reenable interrupts that device may have lost or
820 	 * BIOS/firmware may have disabled
821 	 */
822 	rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), priv->irq);
823 	if (rc < 0)
824 		return;
825 
826 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
827 	if (rc < 0)
828 		return;
829 
830 	intmask |= TPM_INTF_CMD_READY_INT
831 	    | TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_DATA_AVAIL_INT
832 	    | TPM_INTF_STS_VALID_INT | TPM_GLOBAL_INT_ENABLE;
833 
834 	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
835 }
836 
837 int tpm_tis_resume(struct device *dev)
838 {
839 	struct tpm_chip *chip = dev_get_drvdata(dev);
840 	int ret;
841 
842 	if (chip->flags & TPM_CHIP_FLAG_IRQ)
843 		tpm_tis_reenable_interrupts(chip);
844 
845 	ret = tpm_pm_resume(dev);
846 	if (ret)
847 		return ret;
848 
849 	/* TPM 1.2 requires self-test on resume. This function actually returns
850 	 * an error code but for unknown reason it isn't handled.
851 	 */
852 	if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
853 		tpm_do_selftest(chip);
854 
855 	return 0;
856 }
857 EXPORT_SYMBOL_GPL(tpm_tis_resume);
858 #endif
859 
860 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
861 MODULE_DESCRIPTION("TPM Driver");
862 MODULE_VERSION("2.0");
863 MODULE_LICENSE("GPL");
864