summaryrefslogtreecommitdiff
path: root/src/drivers/pc80/tpm/tis.c
blob: 48e529ad9ffe93e4aa8da890bfca8179f3b20f24 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
/* SPDX-License-Identifier: GPL-2.0-only */

/*
 * The code in this file has been heavily based on the article "Writing a TPM
 * Device Driver" published on http://ptgmedia.pearsoncmg.com and the
 * submission by Stefan Berger on Qemu-devel mailing list.
 *
 * One principal difference is that in the simplest config the other than 0
 * TPM localities do not get mapped by some devices (for instance, by
 * Infineon slb9635), so this driver provides access to locality 0 only.
 */

#include <commonlib/helpers.h>
#include <string.h>
#include <delay.h>
#include <device/mmio.h>
#include <acpi/acpi.h>
#include <acpi/acpigen.h>
#include <acpi/acpi_device.h>
#include <device/device.h>
#include <console/console.h>
#include <security/tpm/tis.h>
#include <device/pnp.h>
#include <drivers/tpm/tpm_ppi.h>
#include "chip.h"

#define PREFIX "lpc_tpm: "

/* coreboot wrapper for TPM driver (start) */
#define	TPM_DEBUG(fmt, args...)		\
	if (CONFIG(DEBUG_TPM)) {		\
		printk(BIOS_DEBUG, PREFIX);		\
		printk(BIOS_DEBUG, fmt, ##args);	\
	}
#define TPM_DEBUG_IO_READ(reg_, val_) \
	TPM_DEBUG("Read reg 0x%x returns 0x%x\n", (reg_), (val_))
#define TPM_DEBUG_IO_WRITE(reg_, val_) \
	TPM_DEBUG("Write reg 0x%x with 0x%x\n", (reg_), (val_))
#define printf(x...) printk(BIOS_ERR, x)

/* coreboot wrapper for TPM driver (end) */

/* the macro accepts the locality value, but only locality 0 is operational */
#define TIS_REG(LOCALITY, REG) \
	(void *)(uintptr_t)(CONFIG_TPM_TIS_BASE_ADDRESS + (LOCALITY << 12) + REG)

/* hardware registers' offsets */
#define TIS_REG_ACCESS                 0x0
#define TIS_REG_INT_ENABLE             0x8
#define TIS_REG_INT_VECTOR             0xc
#define TIS_REG_INT_STATUS             0x10
#define TIS_REG_INTF_CAPABILITY        0x14
#define TIS_REG_STS                    0x18
#define TIS_REG_BURST_COUNT            0x19
#define TIS_REG_DATA_FIFO              0x24
#define TIS_REG_DID_VID                0xf00
#define TIS_REG_RID                    0xf04

/* Some registers' bit field definitions */
#define TIS_STS_VALID                  (1 << 7) /* 0x80 */
#define TIS_STS_COMMAND_READY          (1 << 6) /* 0x40 */
#define TIS_STS_TPM_GO                 (1 << 5) /* 0x20 */
#define TIS_STS_DATA_AVAILABLE         (1 << 4) /* 0x10 */
#define TIS_STS_EXPECT                 (1 << 3) /* 0x08 */
#define TIS_STS_RESPONSE_RETRY         (1 << 1) /* 0x02 */

#define TIS_ACCESS_TPM_REG_VALID_STS   (1 << 7) /* 0x80 */
#define TIS_ACCESS_ACTIVE_LOCALITY     (1 << 5) /* 0x20 */
#define TIS_ACCESS_BEEN_SEIZED         (1 << 4) /* 0x10 */
#define TIS_ACCESS_SEIZE               (1 << 3) /* 0x08 */
#define TIS_ACCESS_PENDING_REQUEST     (1 << 2) /* 0x04 */
#define TIS_ACCESS_REQUEST_USE         (1 << 1) /* 0x02 */
#define TIS_ACCESS_TPM_ESTABLISHMENT   (1 << 0) /* 0x01 */

/*
 * Error value returned if a tpm register does not enter the expected state
 * after continuous polling. No actual TPM register reading ever returns ~0,
 * so this value is a safe error indication to be mixed with possible status
 * register values.
 */
#define TPM_TIMEOUT_ERR			(~0)

/* Error value returned on various TPM driver errors */
#define TPM_DRIVER_ERR		(~0)

 /* 1 second is plenty for anything TPM does.*/
#define MAX_DELAY_US	(1000 * 1000)

/*
 * Structures defined below allow creating descriptions of TPM vendor/device
 * ID information for run time discovery. The only device the system knows
 * about at this time is Infineon slb9635
 */
struct device_name {
	u16 dev_id;
	const char *const dev_name;
};

struct vendor_name {
	u16 vendor_id;
	const char *vendor_name;
	const struct device_name *dev_names;
};

static const struct device_name atmel_devices[] = {
	{0x3204, "AT97SC3204"},
	{0xffff}
};

static const struct device_name infineon_devices[] = {
	{0x000b, "SLB9635 TT 1.2"},
#if CONFIG(TPM2)
	{0x001a, "SLB9665 TT 2.0"},
	{0x001b, "SLB9670 TT 2.0"},
#else
	{0x001a, "SLB9660 TT 1.2"},
	{0x001b, "SLB9670 TT 1.2"},
#endif
	{0xffff}
};

static const struct device_name nuvoton_devices[] = {
	{0x00fe, "NPCT420AA V2"},
	{0xffff}
};

static const struct device_name stmicro_devices[] = {
	{0x0000, "ST33ZP24" },
	{0xffff}
};

static const struct device_name swtpm_devices[] = {
#if CONFIG(TPM2)
	{0x0001, "SwTPM 2.0" },
#endif
	{0xffff}
};

static const struct vendor_name vendor_names[] = {
	{0x1114, "Atmel", atmel_devices},
	{0x15d1, "Infineon", infineon_devices},
	{0x1050, "Nuvoton", nuvoton_devices},
	{0x1014, "TPM Emulator", swtpm_devices},
	{0x104a, "ST Microelectronics", stmicro_devices},
};

/*
 * Cached vendor/device ID pair to indicate that the device has been already
 * discovered
 */
static u32 vendor_dev_id;

static inline u8 tpm_read_status(int locality)
{
	u8 value = read8(TIS_REG(locality, TIS_REG_STS));
	TPM_DEBUG_IO_READ(TIS_REG_STS, value);
	return value;
}

static inline void tpm_write_status(u8 sts, int locality)
{
	TPM_DEBUG_IO_WRITE(TIS_REG_STS, sts);
	write8(TIS_REG(locality, TIS_REG_STS), sts);
}

static inline u8 tpm_read_data(int locality)
{
	u8 value = read8(TIS_REG(locality, TIS_REG_DATA_FIFO));
	TPM_DEBUG_IO_READ(TIS_REG_DATA_FIFO, value);
	return value;
}

static inline void tpm_write_data(u8 data, int locality)
{
	TPM_DEBUG_IO_WRITE(TIS_REG_STS, data);
	write8(TIS_REG(locality, TIS_REG_DATA_FIFO), data);
}

static inline u16 tpm_read_burst_count(int locality)
{
	u16 count;
	count = read8(TIS_REG(locality, TIS_REG_BURST_COUNT));
	count |= read8(TIS_REG(locality, TIS_REG_BURST_COUNT + 1)) << 8;
	TPM_DEBUG_IO_READ(TIS_REG_BURST_COUNT, count);
	return count;
}

static inline u8 tpm_read_access(int locality)
{
	u8 value = read8(TIS_REG(locality, TIS_REG_ACCESS));
	TPM_DEBUG_IO_READ(TIS_REG_ACCESS, value);
	return value;
}

static inline void tpm_write_access(u8 data, int locality)
{
	TPM_DEBUG_IO_WRITE(TIS_REG_ACCESS, data);
	write8(TIS_REG(locality, TIS_REG_ACCESS), data);
}

static inline u32 tpm_read_did_vid(int locality)
{
	u32 value = read32(TIS_REG(locality, TIS_REG_DID_VID));
	TPM_DEBUG_IO_READ(TIS_REG_DID_VID, value);
	return value;
}

static inline void tpm_write_int_vector(int vector, int locality)
{
	TPM_DEBUG_IO_WRITE(TIS_REG_INT_VECTOR, vector);
	write8(TIS_REG(locality, TIS_REG_INT_VECTOR), vector & 0xf);
}

static inline u8 tpm_read_int_vector(int locality)
{
	u8 value = read8(TIS_REG(locality, TIS_REG_INT_VECTOR));
	TPM_DEBUG_IO_READ(TIS_REG_INT_VECTOR, value);
	return value;
}

static inline void tpm_write_int_polarity(int polarity, int locality)
{
	/* Set polarity and leave all other bits at 0 */
	u32 value = (polarity & 0x3) << 3;
	TPM_DEBUG_IO_WRITE(TIS_REG_INT_ENABLE, value);
	write32(TIS_REG(locality, TIS_REG_INT_ENABLE), value);
}

static inline u32 tpm_read_int_polarity(int locality)
{
	/* Get polarity and leave all other bits */
	u32 value = read8(TIS_REG(locality, TIS_REG_INT_ENABLE));
	value = (value >> 3) & 0x3;
	TPM_DEBUG_IO_READ(TIS_REG_INT_ENABLE, value);
	return value;
}

/*
 * tis_wait_sts()
 *
 * Wait for at least a second for a status to change its state to match the
 * expected state. Normally the transition happens within microseconds.
 *
 * @locality - locality
 * @mask - bitmask for the bitfield(s) to watch
 * @expected - value the field(s) are supposed to be set to
 *
 * Returns 0 on success or TPM_TIMEOUT_ERR on timeout.
 */
static int tis_wait_sts(int locality, u8 mask, u8 expected)
{
	u32 time_us = MAX_DELAY_US;
	while (time_us > 0) {
		u8 value = tpm_read_status(locality);
		if ((value & mask) == expected)
			return 0;
		udelay(1); /* 1 us */
		time_us--;
	}
	return TPM_TIMEOUT_ERR;
}

static inline int tis_wait_ready(int locality)
{
	return tis_wait_sts(locality, TIS_STS_COMMAND_READY,
	                    TIS_STS_COMMAND_READY);
}

static inline int tis_wait_valid(int locality)
{
	return tis_wait_sts(locality, TIS_STS_VALID, TIS_STS_VALID);
}

static inline int tis_wait_valid_data(int locality)
{
	const u8 has_data = TIS_STS_DATA_AVAILABLE | TIS_STS_VALID;
	return tis_wait_sts(locality, has_data, has_data);
}

static inline int tis_has_valid_data(int locality)
{
	const u8 has_data = TIS_STS_DATA_AVAILABLE | TIS_STS_VALID;
	return (tpm_read_status(locality) & has_data) == has_data;
}

static inline int tis_expect_data(int locality)
{
	return !!(tpm_read_status(locality) & TIS_STS_EXPECT);
}

/*
 * tis_wait_access()
 *
 * Wait for at least a second for a access to change its state to match the
 * expected state. Normally the transition happens within microseconds.
 *
 * @locality - locality
 * @mask - bitmask for the bitfield(s) to watch
 * @expected - value the field(s) are supposed to be set to
 *
 * Returns 0 on success or TPM_TIMEOUT_ERR on timeout.
 */
static int tis_wait_access(int locality, u8 mask, u8 expected)
{
	u32 time_us = MAX_DELAY_US;
	while (time_us > 0) {
		u8 value = tpm_read_access(locality);
		if ((value & mask) == expected)
			return 0;
		udelay(1); /* 1 us */
		time_us--;
	}
	return TPM_TIMEOUT_ERR;
}

static inline int tis_wait_dropped_access(int locality)
{
	return tis_wait_access(locality, TIS_ACCESS_ACTIVE_LOCALITY, 0);
}

static inline int tis_wait_received_access(int locality)
{
	return tis_wait_access(locality, TIS_ACCESS_ACTIVE_LOCALITY,
	                       TIS_ACCESS_ACTIVE_LOCALITY);
}

static inline int tis_has_access(int locality)
{
	return !!(tpm_read_access(locality) & TIS_ACCESS_ACTIVE_LOCALITY);
}

static inline void tis_request_access(int locality)
{
	tpm_write_access(TIS_ACCESS_REQUEST_USE, locality);
}

static inline void tis_drop_access(int locality)
{
	tpm_write_access(TIS_ACCESS_ACTIVE_LOCALITY, locality);
}

/*
 * PC Client Specific TPM Interface Specification section 11.2.12:
 *
 *  Software must be prepared to send two writes of a "1" to command ready
 *  field: the first to indicate successful read of all the data, thus
 *  clearing the data from the ReadFIFO and freeing the TPM's resources,
 *  and the second to indicate to the TPM it is about to send a new command.
 *
 * In practice not all TPMs behave the same so it is necessary to be
 * flexible when trying to set command ready.
 *
 * Returns 0 on success if the TPM is ready for transactions.
 * Returns TPM_TIMEOUT_ERR if the command ready bit does not get set.
 */
static int tis_command_ready(u8 locality)
{
	u32 status;

	/* 1st attempt to set command ready */
	tpm_write_status(TIS_STS_COMMAND_READY, locality);

	/* Wait for response */
	status = tpm_read_status(locality);

	/* Check if command ready is set yet */
	if (status & TIS_STS_COMMAND_READY)
		return 0;

	/* 2nd attempt to set command ready */
	tpm_write_status(TIS_STS_COMMAND_READY, locality);

	return tis_wait_ready(locality);
}

/*
 * Probe the TPM device and try determining its manufacturer/device name.
 *
 * Returns 0 on success (the device is found or was found during an earlier
 * invocation) or TPM_DRIVER_ERR if the device is not found.
 */
static u32 tis_probe(void)
{
	const char *device_name = "unknown";
	const char *vendor_name = device_name;
	const struct device_name *dev;
	u32 didvid;
	u16 vid, did;
	int i;

	if (vendor_dev_id)
		return 0;  /* Already probed. */

	didvid = tpm_read_did_vid(0);
	if (!didvid || (didvid == 0xffffffff)) {
		printf("%s: No TPM device found\n", __func__);
		return TPM_DRIVER_ERR;
	}

	vendor_dev_id = didvid;

	vid = didvid & 0xffff;
	did = (didvid >> 16) & 0xffff;
	for (i = 0; i < ARRAY_SIZE(vendor_names); i++) {
		int j = 0;
		u16 known_did;
		if (vid == vendor_names[i].vendor_id) {
			vendor_name = vendor_names[i].vendor_name;
		} else {
			continue;
		}
		dev = &vendor_names[i].dev_names[j];
		while ((known_did = dev->dev_id) != 0xffff) {
			if (known_did == did) {
				device_name = dev->dev_name;
				break;
			}
			j++;
			dev = &vendor_names[i].dev_names[j];
		}
		break;
	}
	/* this will have to be converted into debug printout */
	printk(BIOS_INFO, "Found TPM %s by %s\n", device_name, vendor_name);
	return 0;
}

/*
 * tis_senddata()
 *
 * send the passed in data to the TPM device.
 *
 * @data - address of the data to send, byte by byte
 * @len - length of the data to send
 *
 * Returns 0 on success, TPM_DRIVER_ERR on error (in case the device does
 * not accept the entire command).
 */
static u32 tis_senddata(const u8 *const data, u32 len)
{
	u32 offset = 0;
	u16 burst = 0;
	u32 max_cycles = 0;
	u8 locality = 0;

	if (tis_wait_ready(locality)) {
		printf("%s:%d - failed to get 'command_ready' status\n",
		       __FILE__, __LINE__);
		return TPM_DRIVER_ERR;
	}
	burst = tpm_read_burst_count(locality);

	while (1) {
		unsigned int count;

		/* Wait till the device is ready to accept more data. */
		while (!burst) {
			if (max_cycles++ == MAX_DELAY_US) {
				printf("%s:%d failed to feed %d bytes of %d\n",
				       __FILE__, __LINE__, len - offset, len);
				return TPM_DRIVER_ERR;
			}
			udelay(1);
			burst = tpm_read_burst_count(locality);
		}

		max_cycles = 0;

		/*
		 * Calculate number of bytes the TPM is ready to accept in one
		 * shot.
		 *
		 * We want to send the last byte outside of the loop (hence
		 * the -1 below) to make sure that the 'expected' status bit
		 * changes to zero exactly after the last byte is fed into the
		 * FIFO.
		 */
		count = MIN(burst, len - offset - 1);
		while (count--)
			tpm_write_data(data[offset++], locality);

		if (tis_wait_valid(locality) || !tis_expect_data(locality)) {
			printf("%s:%d TPM command feed overflow\n",
			       __FILE__, __LINE__);
			return TPM_DRIVER_ERR;
		}

		burst = tpm_read_burst_count(locality);
		if ((offset == (len - 1)) && burst)
			/*
			 * We need to be able to send the last byte to the
			 * device, so burst size must be nonzero before we
			 * break out.
			 */
			break;
	}

	/* Send the last byte. */
	tpm_write_data(data[offset++], locality);

	/*
	 * Verify that TPM does not expect any more data as part of this
	 * command.
	 */
	if (tis_wait_valid(locality) || tis_expect_data(locality)) {
		printf("%s:%d unexpected TPM status 0x%x\n",
		       __FILE__, __LINE__, tpm_read_status(locality));
		return TPM_DRIVER_ERR;
	}

	/* OK, sitting pretty, let's start the command execution. */
	tpm_write_status(TIS_STS_TPM_GO, locality);

	return 0;
}

/*
 * tis_readresponse()
 *
 * read the TPM device response after a command was issued.
 *
 * @buffer - address where to read the response, byte by byte.
 * @len - pointer to the size of buffer
 *
 * On success stores the number of received bytes to len and returns 0. On
 * errors (misformatted TPM data or synchronization problems) returns
 * TPM_DRIVER_ERR.
 */
static u32 tis_readresponse(u8 *buffer, size_t *len)
{
	u16 burst_count;
	u32 offset = 0;
	u8 locality = 0;
	u32 expected_count = *len;
	int max_cycles = 0;

	/* Wait for the TPM to process the command */
	if (tis_wait_valid_data(locality)) {
		printf("%s:%d failed processing command\n", __FILE__, __LINE__);
		return TPM_DRIVER_ERR;
	}

	do {
		while ((burst_count = tpm_read_burst_count(locality)) == 0) {
			if (max_cycles++ == MAX_DELAY_US) {
				printf("%s:%d TPM stuck on read\n",
				       __FILE__, __LINE__);
				return TPM_DRIVER_ERR;
			}
			udelay(1);
		}

		max_cycles = 0;

		while (burst_count-- && (offset < expected_count)) {
			buffer[offset++] = tpm_read_data(locality);
			if (offset == 6) {
				/*
				 * We got the first six bytes of the reply,
				 * let's figure out how many bytes to expect
				 * total - it is stored as a 4 byte number in
				 * network order, starting with offset 2 into
				 * the body of the reply.
				 */
				u32 real_length;
				memcpy(&real_length,
				       buffer + 2,
				       sizeof(real_length));
				expected_count = be32_to_cpu(real_length);

				if ((expected_count < offset) ||
				    (expected_count > *len)) {
					printf("%s:%d bad response size %d\n",
					       __FILE__, __LINE__,
					       expected_count);
					return TPM_DRIVER_ERR;
				}
			}
		}

		/* Wait for the next portion */
		if (tis_wait_valid(locality)) {
			printf("%s:%d failed to read response\n",
			       __FILE__, __LINE__);
			return TPM_DRIVER_ERR;
		}

		if (offset == expected_count)
			break;	/* We got all we need */

		/*
		 * Certain TPMs seem to need some delay between tis_wait_valid()
		 * and tis_has_valid_data(), or some race-condition-related
		 * issue will occur.
		 */
		if (CONFIG(TPM_RDRESP_NEED_DELAY))
			udelay(10);

	} while (tis_has_valid_data(locality));

	/* * Make sure we indeed read all there was. */
	if (tis_has_valid_data(locality)) {
		printf("%s:%d wrong receive status: %x %d bytes left\n",
		       __FILE__, __LINE__, tpm_read_status(locality),
	               tpm_read_burst_count(locality));
		return TPM_DRIVER_ERR;
	}

	/* Tell the TPM that we are done. */
	if (tis_command_ready(locality) == TPM_TIMEOUT_ERR)
		return TPM_DRIVER_ERR;

	*len = offset;
	return 0;
}

/*
 * tis_init()
 *
 * Initialize the TPM device. Returns 0 on success or TPM_DRIVER_ERR on
 * failure (in case device probing did not succeed).
 */
int tis_init(void)
{
	if (tis_probe())
		return TPM_DRIVER_ERR;
	return 0;
}

/*
 * tis_open()
 *
 * Requests access to locality 0 for the caller. After all commands have been
 * completed the caller is supposed to call tis_close().
 *
 * Returns 0 on success, TPM_DRIVER_ERR on failure.
 */
int tis_open(void)
{
	u8 locality = 0; /* we use locality zero for everything */

	if (tis_close())
		return TPM_DRIVER_ERR;

	/* now request access to locality */
	tis_request_access(locality);

	/* did we get a lock? */
	if (tis_wait_received_access(locality)) {
		printf("%s:%d - failed to lock locality %d\n",
		       __FILE__, __LINE__, locality);
		return TPM_DRIVER_ERR;
	}

	/* Certain TPMs seem to need some delay here or they hang... */
	udelay(10);

	if (tis_command_ready(locality) == TPM_TIMEOUT_ERR)
		return TPM_DRIVER_ERR;

	return 0;
}

/*
 * tis_close()
 *
 * terminate the current session with the TPM by releasing the locked
 * locality. Returns 0 on success of TPM_DRIVER_ERR on failure (in case lock
 * removal did not succeed).
 */
int tis_close(void)
{
	u8 locality = 0;
	if (tis_has_access(locality)) {
		tis_drop_access(locality);
		if (tis_wait_dropped_access(locality)) {
			printf("%s:%d - failed to release locality %d\n",
			       __FILE__, __LINE__, locality);
			return TPM_DRIVER_ERR;
		}
	}
	return 0;
}

/*
 * tis_sendrecv()
 *
 * Send the requested data to the TPM and then try to get its response
 *
 * @sendbuf - buffer of the data to send
 * @send_size size of the data to send
 * @recvbuf - memory to save the response to
 * @recv_len - pointer to the size of the response buffer
 *
 * Returns 0 on success (and places the number of response bytes at recv_len)
 * or TPM_DRIVER_ERR on failure.
 */
int tis_sendrecv(const uint8_t *sendbuf, size_t send_size,
		 uint8_t *recvbuf, size_t *recv_len)
{
	if (tis_senddata(sendbuf, send_size)) {
		printf("%s:%d failed sending data to TPM\n",
		       __FILE__, __LINE__);
		return TPM_DRIVER_ERR;
	}

	return tis_readresponse(recvbuf, recv_len);
}

/*
 * tis_setup_interrupt()
 *
 * Set up the interrupt vector and polarity for locality 0 and
 * disable all interrupts so they are unused in firmware but can
 * be enabled by the OS.
 *
 * The values used here must match what is passed in the TPM ACPI
 * device if ACPI is used on the platform.
 *
 * @vector - TPM interrupt vector
 * @polarity - TPM interrupt polarity
 *
 * Returns 0 on success, TPM_DRIVER_ERR on failure.
 */
static int tis_setup_interrupt(int vector, int polarity)
{
	u8 locality = 0;
	int has_access = tis_has_access(locality);

	/* Open connection and request access if not already granted */
	if (!has_access && tis_open() < 0)
		return TPM_DRIVER_ERR;

	/* Set TPM interrupt vector */
	tpm_write_int_vector(vector, locality);

	/* Set TPM interrupt polarity and disable interrupts */
	tpm_write_int_polarity(polarity, locality);

	/* Close connection if it was opened */
	if (!has_access && tis_close() < 0)
		return TPM_DRIVER_ERR;

	return 0;
}

static void lpc_tpm_read_resources(struct device *dev)
{
	/* Static 5K memory region specified in Kconfig */
	mmio_resource(dev, 0, CONFIG_TPM_TIS_BASE_ADDRESS >> 10, 0x5000 >> 10);
}

static void lpc_tpm_set_resources(struct device *dev)
{
	tpm_config_t *config = (tpm_config_t *)dev->chip_info;
	DEVTREE_CONST struct resource *res;

	for (res = dev->resource_list; res; res = res->next) {
		if (!(res->flags & IORESOURCE_ASSIGNED))
			continue;

		if (res->flags & IORESOURCE_IRQ) {
			/* Set interrupt vector */
			tis_setup_interrupt((int)res->base,
					    config->irq_polarity);
		} else {
			continue;
		}

#if !DEVTREE_EARLY
		res->flags |= IORESOURCE_STORED;
		report_resource_stored(dev, res, " <tpm>");
#endif
	}
}

#if CONFIG(HAVE_ACPI_TABLES)
static void lpc_tpm_fill_ssdt(const struct device *dev)
{
	const char *path = acpi_device_path(dev->bus->dev);

	if (!path) {
		path = "\\_SB_.PCI0.LPCB";
		printk(BIOS_DEBUG, "Using default TPM ACPI path: '%s'\n", path);
	}

	/* Device */
	acpigen_write_scope(path);
	acpigen_write_device(acpi_device_name(dev));

	if (CONFIG(TPM2)) {
		acpigen_write_name_string("_HID", "MSFT0101");
		acpigen_write_name_string("_CID", "MSFT0101");
	} else {
		acpigen_write_name("_HID");
		acpigen_emit_eisaid("PNP0C31");

		acpigen_write_name("_CID");
		acpigen_emit_eisaid("PNP0C31");
	}

	acpi_device_write_uid(dev);

	u32 did_vid = tpm_read_did_vid(0);
	if (did_vid > 0 && did_vid < 0xffffffff)
		acpigen_write_STA(ACPI_STATUS_DEVICE_ALL_ON);
	else
		acpigen_write_STA(ACPI_STATUS_DEVICE_ALL_OFF);

	u16 port = dev->path.pnp.port;

	/* Resources */
	acpigen_write_name("_CRS");
	acpigen_write_resourcetemplate_header();
	acpigen_write_mem32fixed(1, CONFIG_TPM_TIS_BASE_ADDRESS, 0x5000);
	if (port)
		acpigen_write_io16(port, port, 1, 2, 1);

	if (CONFIG_TPM_PIRQ) {
		/*
		 * PIRQ: Update interrupt vector with configured PIRQ
		 * Active-Low Level-Triggered Shared
		 */
		struct acpi_irq tpm_irq_a = ACPI_IRQ_LEVEL_LOW(CONFIG_TPM_PIRQ);
		acpi_device_write_interrupt(&tpm_irq_a);
	} else if (tpm_read_int_vector(0) > 0) {
		u8 int_vec = tpm_read_int_vector(0);
		u8 int_pol = tpm_read_int_polarity(0);
		struct acpi_irq tpm_irq = ACPI_IRQ_LEVEL_LOW(int_vec);

		if (int_pol & 1)
			tpm_irq.polarity = ACPI_IRQ_ACTIVE_LOW;
		else
			tpm_irq.polarity = ACPI_IRQ_ACTIVE_HIGH;

		if (int_pol & 2)
			tpm_irq.mode = ACPI_IRQ_EDGE_TRIGGERED;
		else
			tpm_irq.mode = ACPI_IRQ_LEVEL_TRIGGERED;

		acpi_device_write_interrupt(&tpm_irq);
	}


	acpigen_write_resourcetemplate_footer();

	if (!CONFIG(CHROMEOS))
		tpm_ppi_acpi_fill_ssdt(dev);

	acpigen_pop_len(); /* Device */
	acpigen_pop_len(); /* Scope */

#if !DEVTREE_EARLY
	printk(BIOS_INFO, "%s.%s: %s %s\n", path, acpi_device_name(dev),
	       dev->chip_ops->name, dev_path(dev));
#endif
}

static const char *lpc_tpm_acpi_name(const struct device *dev)
{
	return "TPM";
}
#endif

static struct device_operations lpc_tpm_ops = {
	.read_resources   = lpc_tpm_read_resources,
	.set_resources    = lpc_tpm_set_resources,
#if CONFIG(HAVE_ACPI_TABLES)
	.acpi_name        = lpc_tpm_acpi_name,
	.acpi_fill_ssdt   = lpc_tpm_fill_ssdt,
#endif
};

static struct pnp_info pnp_dev_info[] = {
	{ .flags = PNP_IRQ0 }
};

static void enable_dev(struct device *dev)
{
	if (CONFIG(TPM1) || CONFIG(TPM2))
		pnp_enable_devices(dev, &lpc_tpm_ops,
			ARRAY_SIZE(pnp_dev_info), pnp_dev_info);
}

struct chip_operations drivers_pc80_tpm_ops = {
	CHIP_NAME("LPC TPM")
	.enable_dev = enable_dev
};