1 /*
2 * Copyright (C) 2012,2013 Infineon Technologies
3 *
4 * Authors:
5 * Peter Huewe <peter.huewe@infineon.com>
6 *
7 * Device driver for TCG/TCPA TPM (trusted platform module).
8 * Specifications at www.trustedcomputinggroup.org
9 *
10 * This device driver implements the TPM interface as defined in
11 * the TCG TPM Interface Spec version 1.2, revision 1.0 and the
12 * Infineon I2C Protocol Stack Specification v0.20.
13 *
14 * It is based on the original tpm_tis device driver from Leendert van
15 * Dorn and Kyleen Hall.
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 *
23 */
24 #include <linux/i2c.h>
25 #include <linux/module.h>
26 #include <linux/wait.h>
27 #include "tpm.h"
28
29 #define TPM_I2C_INFINEON_BUFSIZE 1260
30
31 /* max. number of iterations after I2C NAK */
32 #define MAX_COUNT 3
33
34 #define SLEEP_DURATION_LOW 55
35 #define SLEEP_DURATION_HI 65
36
37 /* max. number of iterations after I2C NAK for 'long' commands
38 * we need this especially for sending TPM_READY, since the cleanup after the
39 * transtion to the ready state may take some time, but it is unpredictable
40 * how long it will take.
41 */
42 #define MAX_COUNT_LONG 50
43
44 #define SLEEP_DURATION_LONG_LOW 200
45 #define SLEEP_DURATION_LONG_HI 220
46
47 /* After sending TPM_READY to 'reset' the TPM we have to sleep even longer */
48 #define SLEEP_DURATION_RESET_LOW 2400
49 #define SLEEP_DURATION_RESET_HI 2600
50
51 /* we want to use usleep_range instead of msleep for the 5ms TPM_TIMEOUT */
52 #define TPM_TIMEOUT_US_LOW (TPM_TIMEOUT * 1000)
53 #define TPM_TIMEOUT_US_HI (TPM_TIMEOUT_US_LOW + 2000)
54
55 /* expected value for DIDVID register */
56 #define TPM_TIS_I2C_DID_VID_9635 0xd1150b00L
57 #define TPM_TIS_I2C_DID_VID_9645 0x001a15d1L
58
59 enum i2c_chip_type {
60 SLB9635,
61 SLB9645,
62 UNKNOWN,
63 };
64
65 struct tpm_inf_dev {
66 struct i2c_client *client;
67 int locality;
68 /* In addition to the data itself, the buffer must fit the 7-bit I2C
69 * address and the direction bit.
70 */
71 u8 buf[TPM_I2C_INFINEON_BUFSIZE + 1];
72 struct tpm_chip *chip;
73 enum i2c_chip_type chip_type;
74 unsigned int adapterlimit;
75 };
76
77 static struct tpm_inf_dev tpm_dev;
78
79 /*
80 * iic_tpm_read() - read from TPM register
81 * @addr: register address to read from
82 * @buffer: provided by caller
83 * @len: number of bytes to read
84 *
85 * Read len bytes from TPM register and put them into
86 * buffer (little-endian format, i.e. first byte is put into buffer[0]).
87 *
88 * NOTE: TPM is big-endian for multi-byte values. Multi-byte
89 * values have to be swapped.
90 *
91 * NOTE: We can't unfortunately use the combined read/write functions
92 * provided by the i2c core as the TPM currently does not support the
93 * repeated start condition and due to it's special requirements.
94 * The i2c_smbus* functions do not work for this chip.
95 *
96 * Return -EIO on error, 0 on success.
97 */
iic_tpm_read(u8 addr,u8 * buffer,size_t len)98 static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
99 {
100
101 struct i2c_msg msg1 = {
102 .addr = tpm_dev.client->addr,
103 .len = 1,
104 .buf = &addr
105 };
106 struct i2c_msg msg2 = {
107 .addr = tpm_dev.client->addr,
108 .flags = I2C_M_RD,
109 .len = len,
110 .buf = buffer
111 };
112 struct i2c_msg msgs[] = {msg1, msg2};
113
114 int rc = 0;
115 int count;
116 unsigned int msglen = len;
117
118 /* Lock the adapter for the duration of the whole sequence. */
119 if (!tpm_dev.client->adapter->algo->master_xfer)
120 return -EOPNOTSUPP;
121 i2c_lock_bus(tpm_dev.client->adapter, I2C_LOCK_SEGMENT);
122
123 if (tpm_dev.chip_type == SLB9645) {
124 /* use a combined read for newer chips
125 * unfortunately the smbus functions are not suitable due to
126 * the 32 byte limit of the smbus.
127 * retries should usually not be needed, but are kept just to
128 * be on the safe side.
129 */
130 for (count = 0; count < MAX_COUNT; count++) {
131 rc = __i2c_transfer(tpm_dev.client->adapter, msgs, 2);
132 if (rc > 0)
133 break; /* break here to skip sleep */
134 usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
135 }
136 } else {
137 /* Expect to send one command message and one data message, but
138 * support looping over each or both if necessary.
139 */
140 while (len > 0) {
141 /* slb9635 protocol should work in all cases */
142 for (count = 0; count < MAX_COUNT; count++) {
143 rc = __i2c_transfer(tpm_dev.client->adapter,
144 &msg1, 1);
145 if (rc > 0)
146 break; /* break here to skip sleep */
147
148 usleep_range(SLEEP_DURATION_LOW,
149 SLEEP_DURATION_HI);
150 }
151
152 if (rc <= 0)
153 goto out;
154
155 /* After the TPM has successfully received the register
156 * address it needs some time, thus we're sleeping here
157 * again, before retrieving the data
158 */
159 for (count = 0; count < MAX_COUNT; count++) {
160 if (tpm_dev.adapterlimit) {
161 msglen = min_t(unsigned int,
162 tpm_dev.adapterlimit,
163 len);
164 msg2.len = msglen;
165 }
166 usleep_range(SLEEP_DURATION_LOW,
167 SLEEP_DURATION_HI);
168 rc = __i2c_transfer(tpm_dev.client->adapter,
169 &msg2, 1);
170 if (rc > 0) {
171 /* Since len is unsigned, make doubly
172 * sure we do not underflow it.
173 */
174 if (msglen > len)
175 len = 0;
176 else
177 len -= msglen;
178 msg2.buf += msglen;
179 break;
180 }
181 /* If the I2C adapter rejected the request (e.g
182 * when the quirk read_max_len < len) fall back
183 * to a sane minimum value and try again.
184 */
185 if (rc == -EOPNOTSUPP)
186 tpm_dev.adapterlimit =
187 I2C_SMBUS_BLOCK_MAX;
188 }
189
190 if (rc <= 0)
191 goto out;
192 }
193 }
194
195 out:
196 i2c_unlock_bus(tpm_dev.client->adapter, I2C_LOCK_SEGMENT);
197 /* take care of 'guard time' */
198 usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
199
200 /* __i2c_transfer returns the number of successfully transferred
201 * messages.
202 * So rc should be greater than 0 here otherwise we have an error.
203 */
204 if (rc <= 0)
205 return -EIO;
206
207 return 0;
208 }
209
iic_tpm_write_generic(u8 addr,u8 * buffer,size_t len,unsigned int sleep_low,unsigned int sleep_hi,u8 max_count)210 static int iic_tpm_write_generic(u8 addr, u8 *buffer, size_t len,
211 unsigned int sleep_low,
212 unsigned int sleep_hi, u8 max_count)
213 {
214 int rc = -EIO;
215 int count;
216
217 struct i2c_msg msg1 = {
218 .addr = tpm_dev.client->addr,
219 .len = len + 1,
220 .buf = tpm_dev.buf
221 };
222
223 if (len > TPM_I2C_INFINEON_BUFSIZE)
224 return -EINVAL;
225
226 if (!tpm_dev.client->adapter->algo->master_xfer)
227 return -EOPNOTSUPP;
228 i2c_lock_bus(tpm_dev.client->adapter, I2C_LOCK_SEGMENT);
229
230 /* prepend the 'register address' to the buffer */
231 tpm_dev.buf[0] = addr;
232 memcpy(&(tpm_dev.buf[1]), buffer, len);
233
234 /*
235 * NOTE: We have to use these special mechanisms here and unfortunately
236 * cannot rely on the standard behavior of i2c_transfer.
237 * Even for newer chips the smbus functions are not
238 * suitable due to the 32 byte limit of the smbus.
239 */
240 for (count = 0; count < max_count; count++) {
241 rc = __i2c_transfer(tpm_dev.client->adapter, &msg1, 1);
242 if (rc > 0)
243 break;
244 usleep_range(sleep_low, sleep_hi);
245 }
246
247 i2c_unlock_bus(tpm_dev.client->adapter, I2C_LOCK_SEGMENT);
248 /* take care of 'guard time' */
249 usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
250
251 /* __i2c_transfer returns the number of successfully transferred
252 * messages.
253 * So rc should be greater than 0 here otherwise we have an error.
254 */
255 if (rc <= 0)
256 return -EIO;
257
258 return 0;
259 }
260
261 /*
262 * iic_tpm_write() - write to TPM register
263 * @addr: register address to write to
264 * @buffer: containing data to be written
265 * @len: number of bytes to write
266 *
267 * Write len bytes from provided buffer to TPM register (little
268 * endian format, i.e. buffer[0] is written as first byte).
269 *
270 * NOTE: TPM is big-endian for multi-byte values. Multi-byte
271 * values have to be swapped.
272 *
273 * NOTE: use this function instead of the iic_tpm_write_generic function.
274 *
275 * Return -EIO on error, 0 on success
276 */
iic_tpm_write(u8 addr,u8 * buffer,size_t len)277 static int iic_tpm_write(u8 addr, u8 *buffer, size_t len)
278 {
279 return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION_LOW,
280 SLEEP_DURATION_HI, MAX_COUNT);
281 }
282
283 /*
284 * This function is needed especially for the cleanup situation after
285 * sending TPM_READY
286 * */
iic_tpm_write_long(u8 addr,u8 * buffer,size_t len)287 static int iic_tpm_write_long(u8 addr, u8 *buffer, size_t len)
288 {
289 return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION_LONG_LOW,
290 SLEEP_DURATION_LONG_HI, MAX_COUNT_LONG);
291 }
292
293 enum tis_access {
294 TPM_ACCESS_VALID = 0x80,
295 TPM_ACCESS_ACTIVE_LOCALITY = 0x20,
296 TPM_ACCESS_REQUEST_PENDING = 0x04,
297 TPM_ACCESS_REQUEST_USE = 0x02,
298 };
299
300 enum tis_status {
301 TPM_STS_VALID = 0x80,
302 TPM_STS_COMMAND_READY = 0x40,
303 TPM_STS_GO = 0x20,
304 TPM_STS_DATA_AVAIL = 0x10,
305 TPM_STS_DATA_EXPECT = 0x08,
306 };
307
308 enum tis_defaults {
309 TIS_SHORT_TIMEOUT = 750, /* ms */
310 TIS_LONG_TIMEOUT = 2000, /* 2 sec */
311 };
312
313 #define TPM_ACCESS(l) (0x0000 | ((l) << 4))
314 #define TPM_STS(l) (0x0001 | ((l) << 4))
315 #define TPM_DATA_FIFO(l) (0x0005 | ((l) << 4))
316 #define TPM_DID_VID(l) (0x0006 | ((l) << 4))
317
check_locality(struct tpm_chip * chip,int loc)318 static bool check_locality(struct tpm_chip *chip, int loc)
319 {
320 u8 buf;
321 int rc;
322
323 rc = iic_tpm_read(TPM_ACCESS(loc), &buf, 1);
324 if (rc < 0)
325 return false;
326
327 if ((buf & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
328 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) {
329 tpm_dev.locality = loc;
330 return true;
331 }
332
333 return false;
334 }
335
336 /* implementation similar to tpm_tis */
release_locality(struct tpm_chip * chip,int loc,int force)337 static void release_locality(struct tpm_chip *chip, int loc, int force)
338 {
339 u8 buf;
340 if (iic_tpm_read(TPM_ACCESS(loc), &buf, 1) < 0)
341 return;
342
343 if (force || (buf & (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) ==
344 (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) {
345 buf = TPM_ACCESS_ACTIVE_LOCALITY;
346 iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
347 }
348 }
349
request_locality(struct tpm_chip * chip,int loc)350 static int request_locality(struct tpm_chip *chip, int loc)
351 {
352 unsigned long stop;
353 u8 buf = TPM_ACCESS_REQUEST_USE;
354
355 if (check_locality(chip, loc))
356 return loc;
357
358 iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
359
360 /* wait for burstcount */
361 stop = jiffies + chip->timeout_a;
362 do {
363 if (check_locality(chip, loc))
364 return loc;
365 usleep_range(TPM_TIMEOUT_US_LOW, TPM_TIMEOUT_US_HI);
366 } while (time_before(jiffies, stop));
367
368 return -ETIME;
369 }
370
tpm_tis_i2c_status(struct tpm_chip * chip)371 static u8 tpm_tis_i2c_status(struct tpm_chip *chip)
372 {
373 /* NOTE: since I2C read may fail, return 0 in this case --> time-out */
374 u8 buf = 0xFF;
375 u8 i = 0;
376
377 do {
378 if (iic_tpm_read(TPM_STS(tpm_dev.locality), &buf, 1) < 0)
379 return 0;
380
381 i++;
382 /* if locallity is set STS should not be 0xFF */
383 } while ((buf == 0xFF) && i < 10);
384
385 return buf;
386 }
387
tpm_tis_i2c_ready(struct tpm_chip * chip)388 static void tpm_tis_i2c_ready(struct tpm_chip *chip)
389 {
390 /* this causes the current command to be aborted */
391 u8 buf = TPM_STS_COMMAND_READY;
392 iic_tpm_write_long(TPM_STS(tpm_dev.locality), &buf, 1);
393 }
394
get_burstcount(struct tpm_chip * chip)395 static ssize_t get_burstcount(struct tpm_chip *chip)
396 {
397 unsigned long stop;
398 ssize_t burstcnt;
399 u8 buf[3];
400
401 /* wait for burstcount */
402 /* which timeout value, spec has 2 answers (c & d) */
403 stop = jiffies + chip->timeout_d;
404 do {
405 /* Note: STS is little endian */
406 if (iic_tpm_read(TPM_STS(tpm_dev.locality)+1, buf, 3) < 0)
407 burstcnt = 0;
408 else
409 burstcnt = (buf[2] << 16) + (buf[1] << 8) + buf[0];
410
411 if (burstcnt)
412 return burstcnt;
413
414 usleep_range(TPM_TIMEOUT_US_LOW, TPM_TIMEOUT_US_HI);
415 } while (time_before(jiffies, stop));
416 return -EBUSY;
417 }
418
wait_for_stat(struct tpm_chip * chip,u8 mask,unsigned long timeout,int * status)419 static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
420 int *status)
421 {
422 unsigned long stop;
423
424 /* check current status */
425 *status = tpm_tis_i2c_status(chip);
426 if ((*status != 0xFF) && (*status & mask) == mask)
427 return 0;
428
429 stop = jiffies + timeout;
430 do {
431 /* since we just checked the status, give the TPM some time */
432 usleep_range(TPM_TIMEOUT_US_LOW, TPM_TIMEOUT_US_HI);
433 *status = tpm_tis_i2c_status(chip);
434 if ((*status & mask) == mask)
435 return 0;
436
437 } while (time_before(jiffies, stop));
438
439 return -ETIME;
440 }
441
recv_data(struct tpm_chip * chip,u8 * buf,size_t count)442 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
443 {
444 size_t size = 0;
445 ssize_t burstcnt;
446 u8 retries = 0;
447 int rc;
448
449 while (size < count) {
450 burstcnt = get_burstcount(chip);
451
452 /* burstcnt < 0 = TPM is busy */
453 if (burstcnt < 0)
454 return burstcnt;
455
456 /* limit received data to max. left */
457 if (burstcnt > (count - size))
458 burstcnt = count - size;
459
460 rc = iic_tpm_read(TPM_DATA_FIFO(tpm_dev.locality),
461 &(buf[size]), burstcnt);
462 if (rc == 0)
463 size += burstcnt;
464 else if (rc < 0)
465 retries++;
466
467 /* avoid endless loop in case of broken HW */
468 if (retries > MAX_COUNT_LONG)
469 return -EIO;
470 }
471 return size;
472 }
473
tpm_tis_i2c_recv(struct tpm_chip * chip,u8 * buf,size_t count)474 static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
475 {
476 int size = 0;
477 int status;
478 u32 expected;
479
480 if (count < TPM_HEADER_SIZE) {
481 size = -EIO;
482 goto out;
483 }
484
485 /* read first 10 bytes, including tag, paramsize, and result */
486 size = recv_data(chip, buf, TPM_HEADER_SIZE);
487 if (size < TPM_HEADER_SIZE) {
488 dev_err(&chip->dev, "Unable to read header\n");
489 goto out;
490 }
491
492 expected = be32_to_cpu(*(__be32 *)(buf + 2));
493 if (((size_t) expected > count) || (expected < TPM_HEADER_SIZE)) {
494 size = -EIO;
495 goto out;
496 }
497
498 size += recv_data(chip, &buf[TPM_HEADER_SIZE],
499 expected - TPM_HEADER_SIZE);
500 if (size < expected) {
501 dev_err(&chip->dev, "Unable to read remainder of result\n");
502 size = -ETIME;
503 goto out;
504 }
505
506 wait_for_stat(chip, TPM_STS_VALID, chip->timeout_c, &status);
507 if (status & TPM_STS_DATA_AVAIL) { /* retry? */
508 dev_err(&chip->dev, "Error left over data\n");
509 size = -EIO;
510 goto out;
511 }
512
513 out:
514 tpm_tis_i2c_ready(chip);
515 /* The TPM needs some time to clean up here,
516 * so we sleep rather than keeping the bus busy
517 */
518 usleep_range(SLEEP_DURATION_RESET_LOW, SLEEP_DURATION_RESET_HI);
519 release_locality(chip, tpm_dev.locality, 0);
520 return size;
521 }
522
tpm_tis_i2c_send(struct tpm_chip * chip,u8 * buf,size_t len)523 static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len)
524 {
525 int rc, status;
526 ssize_t burstcnt;
527 size_t count = 0;
528 u8 retries = 0;
529 u8 sts = TPM_STS_GO;
530
531 if (len > TPM_I2C_INFINEON_BUFSIZE)
532 return -E2BIG;
533
534 if (request_locality(chip, 0) < 0)
535 return -EBUSY;
536
537 status = tpm_tis_i2c_status(chip);
538 if ((status & TPM_STS_COMMAND_READY) == 0) {
539 tpm_tis_i2c_ready(chip);
540 if (wait_for_stat
541 (chip, TPM_STS_COMMAND_READY,
542 chip->timeout_b, &status) < 0) {
543 rc = -ETIME;
544 goto out_err;
545 }
546 }
547
548 while (count < len - 1) {
549 burstcnt = get_burstcount(chip);
550
551 /* burstcnt < 0 = TPM is busy */
552 if (burstcnt < 0)
553 return burstcnt;
554
555 if (burstcnt > (len - 1 - count))
556 burstcnt = len - 1 - count;
557
558 rc = iic_tpm_write(TPM_DATA_FIFO(tpm_dev.locality),
559 &(buf[count]), burstcnt);
560 if (rc == 0)
561 count += burstcnt;
562 else if (rc < 0)
563 retries++;
564
565 /* avoid endless loop in case of broken HW */
566 if (retries > MAX_COUNT_LONG) {
567 rc = -EIO;
568 goto out_err;
569 }
570
571 wait_for_stat(chip, TPM_STS_VALID,
572 chip->timeout_c, &status);
573
574 if ((status & TPM_STS_DATA_EXPECT) == 0) {
575 rc = -EIO;
576 goto out_err;
577 }
578 }
579
580 /* write last byte */
581 iic_tpm_write(TPM_DATA_FIFO(tpm_dev.locality), &(buf[count]), 1);
582 wait_for_stat(chip, TPM_STS_VALID, chip->timeout_c, &status);
583 if ((status & TPM_STS_DATA_EXPECT) != 0) {
584 rc = -EIO;
585 goto out_err;
586 }
587
588 /* go and do it */
589 iic_tpm_write(TPM_STS(tpm_dev.locality), &sts, 1);
590
591 return 0;
592 out_err:
593 tpm_tis_i2c_ready(chip);
594 /* The TPM needs some time to clean up here,
595 * so we sleep rather than keeping the bus busy
596 */
597 usleep_range(SLEEP_DURATION_RESET_LOW, SLEEP_DURATION_RESET_HI);
598 release_locality(chip, tpm_dev.locality, 0);
599 return rc;
600 }
601
tpm_tis_i2c_req_canceled(struct tpm_chip * chip,u8 status)602 static bool tpm_tis_i2c_req_canceled(struct tpm_chip *chip, u8 status)
603 {
604 return (status == TPM_STS_COMMAND_READY);
605 }
606
607 static const struct tpm_class_ops tpm_tis_i2c = {
608 .flags = TPM_OPS_AUTO_STARTUP,
609 .status = tpm_tis_i2c_status,
610 .recv = tpm_tis_i2c_recv,
611 .send = tpm_tis_i2c_send,
612 .cancel = tpm_tis_i2c_ready,
613 .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
614 .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
615 .req_canceled = tpm_tis_i2c_req_canceled,
616 };
617
tpm_tis_i2c_init(struct device * dev)618 static int tpm_tis_i2c_init(struct device *dev)
619 {
620 u32 vendor;
621 int rc = 0;
622 struct tpm_chip *chip;
623
624 chip = tpmm_chip_alloc(dev, &tpm_tis_i2c);
625 if (IS_ERR(chip))
626 return PTR_ERR(chip);
627
628 /* Default timeouts */
629 chip->timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
630 chip->timeout_b = msecs_to_jiffies(TIS_LONG_TIMEOUT);
631 chip->timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
632 chip->timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
633
634 if (request_locality(chip, 0) != 0) {
635 dev_err(dev, "could not request locality\n");
636 rc = -ENODEV;
637 goto out_err;
638 }
639
640 /* read four bytes from DID_VID register */
641 if (iic_tpm_read(TPM_DID_VID(0), (u8 *)&vendor, 4) < 0) {
642 dev_err(dev, "could not read vendor id\n");
643 rc = -EIO;
644 goto out_release;
645 }
646
647 if (vendor == TPM_TIS_I2C_DID_VID_9645) {
648 tpm_dev.chip_type = SLB9645;
649 } else if (vendor == TPM_TIS_I2C_DID_VID_9635) {
650 tpm_dev.chip_type = SLB9635;
651 } else {
652 dev_err(dev, "vendor id did not match! ID was %08x\n", vendor);
653 rc = -ENODEV;
654 goto out_release;
655 }
656
657 dev_info(dev, "1.2 TPM (device-id 0x%X)\n", vendor >> 16);
658
659 tpm_dev.chip = chip;
660
661 return tpm_chip_register(chip);
662 out_release:
663 release_locality(chip, tpm_dev.locality, 1);
664 tpm_dev.client = NULL;
665 out_err:
666 return rc;
667 }
668
669 static const struct i2c_device_id tpm_tis_i2c_table[] = {
670 {"tpm_i2c_infineon"},
671 {"slb9635tt"},
672 {"slb9645tt"},
673 {},
674 };
675
676 MODULE_DEVICE_TABLE(i2c, tpm_tis_i2c_table);
677
678 #ifdef CONFIG_OF
679 static const struct of_device_id tpm_tis_i2c_of_match[] = {
680 {.compatible = "infineon,tpm_i2c_infineon"},
681 {.compatible = "infineon,slb9635tt"},
682 {.compatible = "infineon,slb9645tt"},
683 {},
684 };
685 MODULE_DEVICE_TABLE(of, tpm_tis_i2c_of_match);
686 #endif
687
688 static SIMPLE_DEV_PM_OPS(tpm_tis_i2c_ops, tpm_pm_suspend, tpm_pm_resume);
689
tpm_tis_i2c_probe(struct i2c_client * client,const struct i2c_device_id * id)690 static int tpm_tis_i2c_probe(struct i2c_client *client,
691 const struct i2c_device_id *id)
692 {
693 int rc;
694 struct device *dev = &(client->dev);
695
696 if (tpm_dev.client != NULL) {
697 dev_err(dev, "This driver only supports one client at a time\n");
698 return -EBUSY; /* We only support one client */
699 }
700
701 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
702 dev_err(dev, "no algorithms associated to the i2c bus\n");
703 return -ENODEV;
704 }
705
706 tpm_dev.client = client;
707 rc = tpm_tis_i2c_init(&client->dev);
708 if (rc != 0) {
709 tpm_dev.client = NULL;
710 rc = -ENODEV;
711 }
712 return rc;
713 }
714
tpm_tis_i2c_remove(struct i2c_client * client)715 static int tpm_tis_i2c_remove(struct i2c_client *client)
716 {
717 struct tpm_chip *chip = tpm_dev.chip;
718
719 tpm_chip_unregister(chip);
720 release_locality(chip, tpm_dev.locality, 1);
721 tpm_dev.client = NULL;
722
723 return 0;
724 }
725
726 static struct i2c_driver tpm_tis_i2c_driver = {
727 .id_table = tpm_tis_i2c_table,
728 .probe = tpm_tis_i2c_probe,
729 .remove = tpm_tis_i2c_remove,
730 .driver = {
731 .name = "tpm_i2c_infineon",
732 .pm = &tpm_tis_i2c_ops,
733 .of_match_table = of_match_ptr(tpm_tis_i2c_of_match),
734 },
735 };
736
737 module_i2c_driver(tpm_tis_i2c_driver);
738 MODULE_AUTHOR("Peter Huewe <peter.huewe@infineon.com>");
739 MODULE_DESCRIPTION("TPM TIS I2C Infineon Driver");
740 MODULE_VERSION("2.2.0");
741 MODULE_LICENSE("GPL");
742