dm: tpm: Convert I2C driver to driver model
[karo-tx-uboot.git] / drivers / tpm / tpm_tis_i2c.c
1 /*
2  * Copyright (C) 2011 Infineon Technologies
3  *
4  * Authors:
5  * Peter Huewe <huewe.external@infineon.com>
6  *
7  * Description:
8  * Device driver for TCG/TCPA TPM (trusted platform module).
9  * Specifications at www.trustedcomputinggroup.org
10  *
11  * This device driver implements the TPM interface as defined in
12  * the TCG TPM Interface Spec version 1.2, revision 1.0 and the
13  * Infineon I2C Protocol Stack Specification v0.20.
14  *
15  * It is based on the Linux kernel driver tpm.c from Leendert van
16  * Dorn, Dave Safford, Reiner Sailer, and Kyleen Hall.
17  *
18  * Version: 2.1.1
19  *
20  * SPDX-License-Identifier:     GPL-2.0
21  */
22
23 #include <common.h>
24 #include <dm.h>
25 #include <fdtdec.h>
26 #include <i2c.h>
27 #include <tis.h>
28 #include <tpm.h>
29 #include <asm-generic/errno.h>
30 #include <linux/compiler.h>
31 #include <linux/types.h>
32 #include <linux/unaligned/be_byteshift.h>
33
34 #include "tpm_tis_i2c.h"
35 #include "tpm_internal.h"
36
37 DECLARE_GLOBAL_DATA_PTR;
38
39 static const char * const chip_name[] = {
40         [SLB9635] = "slb9635tt",
41         [SLB9645] = "slb9645tt",
42         [UNKNOWN] = "unknown/fallback to slb9635",
43 };
44
45 /*
46  * tpm_tis_i2c_read() - read from TPM register
47  * @addr: register address to read from
48  * @buffer: provided by caller
49  * @len: number of bytes to read
50  *
51  * Read len bytes from TPM register and put them into
52  * buffer (little-endian format, i.e. first byte is put into buffer[0]).
53  *
54  * NOTE: TPM is big-endian for multi-byte values. Multi-byte
55  * values have to be swapped.
56  *
57  * Return -EIO on error, 0 on success.
58  */
59 static int tpm_tis_i2c_read(struct udevice *dev, u8 addr, u8 *buffer,
60                             size_t len)
61 {
62         struct tpm_chip *chip = dev_get_priv(dev);
63         int rc;
64         int count;
65         uint32_t addrbuf = addr;
66
67         if ((chip->chip_type == SLB9635) || (chip->chip_type == UNKNOWN)) {
68                 /* slb9635 protocol should work in both cases */
69                 for (count = 0; count < MAX_COUNT; count++) {
70                         rc = dm_i2c_write(dev, 0, (uchar *)&addrbuf, 1);
71                         if (rc == 0)
72                                 break;  /* Success, break to skip sleep */
73                         udelay(SLEEP_DURATION_US);
74                 }
75                 if (rc)
76                         return rc;
77
78                 /* After the TPM has successfully received the register address
79                  * it needs some time, thus we're sleeping here again, before
80                  * retrieving the data
81                  */
82                 for (count = 0; count < MAX_COUNT; count++) {
83                         udelay(SLEEP_DURATION_US);
84                         rc = dm_i2c_read(dev, 0, buffer, len);
85                         if (rc == 0)
86                                 break;  /* success, break to skip sleep */
87                 }
88         } else {
89                 /*
90                  * Use a combined read for newer chips.
91                  * Unfortunately the smbus functions are not suitable due to
92                  * the 32 byte limit of the smbus.
93                  * Retries should usually not be needed, but are kept just to
94                  * be safe on the safe side.
95                  */
96                 for (count = 0; count < MAX_COUNT; count++) {
97                         rc = dm_i2c_read(dev, addr, buffer, len);
98                         if (rc == 0)
99                                 break;  /* break here to skip sleep */
100                         udelay(SLEEP_DURATION_US);
101                 }
102         }
103
104         /* Take care of 'guard time' */
105         udelay(SLEEP_DURATION_US);
106         if (rc)
107                 return rc;
108
109         return 0;
110 }
111
112 static int tpm_tis_i2c_write_generic(struct udevice *dev, u8 addr,
113                                      const u8 *buffer, size_t len,
114                                      unsigned int sleep_time_us, u8 max_count)
115 {
116         struct tpm_chip_priv *priv = dev_get_uclass_priv(dev);
117         struct tpm_chip *chip = dev_get_priv(dev);
118         int rc = 0;
119         int count;
120
121         if (chip->chip_type == SLB9635) {
122                 /* Prepare send buffer to include the address */
123                 priv->buf[0] = addr;
124                 memcpy(&(priv->buf[1]), buffer, len);
125                 buffer = priv->buf;
126                 len++;
127                 addr = 0;
128         }
129
130         for (count = 0; count < max_count; count++) {
131                 rc = dm_i2c_write(dev, addr, buffer, len);
132                 if (rc == 0)
133                         break;  /* Success, break to skip sleep */
134                 udelay(sleep_time_us);
135         }
136
137         /* take care of 'guard time' */
138         udelay(sleep_time_us);
139         if (rc)
140                 return rc;
141
142         return 0;
143 }
144
145 /*
146  * tpm_tis_i2c_write() - write to TPM register
147  * @addr: register address to write to
148  * @buffer: containing data to be written
149  * @len: number of bytes to write
150  *
151  * Write len bytes from provided buffer to TPM register (little
152  * endian format, i.e. buffer[0] is written as first byte).
153  *
154  * NOTE: TPM is big-endian for multi-byte values. Multi-byte
155  * values have to be swapped.
156  *
157  * NOTE: use this function instead of the tpm_tis_i2c_write_generic function.
158  *
159  * Return -EIO on error, 0 on success
160  */
161 static int tpm_tis_i2c_write(struct udevice *dev, u8 addr, const u8 *buffer,
162                              size_t len)
163 {
164         return tpm_tis_i2c_write_generic(dev, addr, buffer, len,
165                                          SLEEP_DURATION_US, MAX_COUNT);
166 }
167
168 /*
169  * This function is needed especially for the cleanup situation after
170  * sending TPM_READY
171  */
172 static int tpm_tis_i2c_write_long(struct udevice *dev, u8 addr, u8 *buffer,
173                                   size_t len)
174 {
175         return tpm_tis_i2c_write_generic(dev, addr, buffer, len,
176                                          SLEEP_DURATION_LONG_US,
177                                          MAX_COUNT_LONG);
178 }
179
180 static int tpm_tis_i2c_check_locality(struct udevice *dev, int loc)
181 {
182         const u8 mask = TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID;
183         struct tpm_chip *chip = dev_get_priv(dev);
184         u8 buf;
185         int rc;
186
187         rc = tpm_tis_i2c_read(dev, TPM_ACCESS(loc), &buf, 1);
188         if (rc < 0)
189                 return rc;
190
191         if ((buf & mask) == mask) {
192                 chip->locality = loc;
193                 return loc;
194         }
195
196         return -ENOENT;
197 }
198
199 static void tpm_tis_i2c_release_locality(struct udevice *dev, int loc,
200                                          int force)
201 {
202         const u8 mask = TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID;
203         u8 buf;
204
205         if (tpm_tis_i2c_read(dev, TPM_ACCESS(loc), &buf, 1) < 0)
206                 return;
207
208         if (force || (buf & mask) == mask) {
209                 buf = TPM_ACCESS_ACTIVE_LOCALITY;
210                 tpm_tis_i2c_write(dev, TPM_ACCESS(loc), &buf, 1);
211         }
212 }
213
214 static int tpm_tis_i2c_request_locality(struct udevice *dev, int loc)
215 {
216         struct tpm_chip *chip = dev_get_priv(dev);
217         unsigned long start, stop;
218         u8 buf = TPM_ACCESS_REQUEST_USE;
219         int rc;
220
221         rc = tpm_tis_i2c_check_locality(dev, loc);
222         if (rc >= 0) {
223                 debug("%s: Already have locality\n", __func__);
224                 return loc;  /* We already have the locality */
225         } else if (rc != -ENOENT) {
226                 debug("%s: Failed to get locality: %d\n", __func__, rc);
227                 return rc;
228         }
229
230         rc = tpm_tis_i2c_write(dev, TPM_ACCESS(loc), &buf, 1);
231         if (rc) {
232                 debug("%s: Failed to write to TPM: %d\n", __func__, rc);
233                 return rc;
234         }
235
236         /* Wait for burstcount */
237         start = get_timer(0);
238         stop = chip->timeout_a;
239         do {
240                 rc = tpm_tis_i2c_check_locality(dev, loc);
241                 if (rc >= 0) {
242                         debug("%s: Have locality\n", __func__);
243                         return loc;
244                 } else if (rc != -ENOENT) {
245                         debug("%s: Failed to get locality: %d\n", __func__, rc);
246                         return rc;
247                 }
248                 mdelay(TPM_TIMEOUT_MS);
249         } while (get_timer(start) < stop);
250         debug("%s: Timeout getting locality: %d\n", __func__, rc);
251
252         return rc;
253 }
254
255 static u8 tpm_tis_i2c_status(struct udevice *dev)
256 {
257         struct tpm_chip *chip = dev_get_priv(dev);
258         /* NOTE: Since i2c read may fail, return 0 in this case --> time-out */
259         u8 buf;
260
261         if (tpm_tis_i2c_read(dev, TPM_STS(chip->locality), &buf, 1) < 0)
262                 return 0;
263         else
264                 return buf;
265 }
266
267 static int tpm_tis_i2c_ready(struct udevice *dev)
268 {
269         struct tpm_chip *chip = dev_get_priv(dev);
270         int rc;
271
272         /* This causes the current command to be aborted */
273         u8 buf = TPM_STS_COMMAND_READY;
274
275         debug("%s\n", __func__);
276         rc = tpm_tis_i2c_write_long(dev, TPM_STS(chip->locality), &buf, 1);
277         if (rc)
278                 debug("%s: rc=%d\n", __func__, rc);
279
280         return rc;
281 }
282
283 static ssize_t tpm_tis_i2c_get_burstcount(struct udevice *dev)
284 {
285         struct tpm_chip *chip = dev_get_priv(dev);
286         unsigned long start, stop;
287         ssize_t burstcnt;
288         u8 addr, buf[3];
289
290         /* Wait for burstcount */
291         /* XXX: Which timeout value? Spec has 2 answers (c & d) */
292         start = get_timer(0);
293         stop = chip->timeout_d;
294         do {
295                 /* Note: STS is little endian */
296                 addr = TPM_STS(chip->locality) + 1;
297                 if (tpm_tis_i2c_read(dev, addr, buf, 3) < 0)
298                         burstcnt = 0;
299                 else
300                         burstcnt = (buf[2] << 16) + (buf[1] << 8) + buf[0];
301
302                 if (burstcnt)
303                         return burstcnt;
304                 mdelay(TPM_TIMEOUT_MS);
305         } while (get_timer(start) < stop);
306
307         return -EBUSY;
308 }
309
310 static int tpm_tis_i2c_wait_for_stat(struct udevice *dev, u8 mask,
311                                      unsigned long timeout, int *status)
312 {
313         unsigned long start, stop;
314
315         /* Check current status */
316         *status = tpm_tis_i2c_status(dev);
317         if ((*status & mask) == mask)
318                 return 0;
319
320         start = get_timer(0);
321         stop = timeout;
322         do {
323                 mdelay(TPM_TIMEOUT_MS);
324                 *status = tpm_tis_i2c_status(dev);
325                 if ((*status & mask) == mask)
326                         return 0;
327         } while (get_timer(start) < stop);
328
329         return -ETIMEDOUT;
330 }
331
332 static int tpm_tis_i2c_recv_data(struct udevice *dev, u8 *buf, size_t count)
333 {
334         struct tpm_chip *chip = dev_get_priv(dev);
335         size_t size = 0;
336         ssize_t burstcnt;
337         int rc;
338
339         while (size < count) {
340                 burstcnt = tpm_tis_i2c_get_burstcount(dev);
341
342                 /* burstcount < 0 -> tpm is busy */
343                 if (burstcnt < 0)
344                         return burstcnt;
345
346                 /* Limit received data to max left */
347                 if (burstcnt > (count - size))
348                         burstcnt = count - size;
349
350                 rc = tpm_tis_i2c_read(dev, TPM_DATA_FIFO(chip->locality),
351                                       &(buf[size]), burstcnt);
352                 if (rc == 0)
353                         size += burstcnt;
354         }
355
356         return size;
357 }
358
359 static int tpm_tis_i2c_recv(struct udevice *dev, u8 *buf, size_t count)
360 {
361         struct tpm_chip *chip = dev_get_priv(dev);
362         int size = 0;
363         int expected, status;
364         int rc;
365
366         status = tpm_tis_i2c_status(dev);
367         if (status == TPM_STS_COMMAND_READY)
368                 return -EINTR;
369         if ((status & (TPM_STS_DATA_AVAIL | TPM_STS_VALID)) !=
370             (TPM_STS_DATA_AVAIL | TPM_STS_VALID))
371                 return -EAGAIN;
372
373         debug("...got it;\n");
374
375         /* Read first 10 bytes, including tag, paramsize, and result */
376         size = tpm_tis_i2c_recv_data(dev, buf, TPM_HEADER_SIZE);
377         if (size < TPM_HEADER_SIZE) {
378                 debug("Unable to read header\n");
379                 return size < 0 ? size : -EIO;
380         }
381
382         expected = get_unaligned_be32(buf + TPM_RSP_SIZE_BYTE);
383         if ((size_t)expected > count) {
384                 debug("Error size=%x, expected=%x, count=%x\n", size, expected,
385                       count);
386                 return -ENOSPC;
387         }
388
389         size += tpm_tis_i2c_recv_data(dev, &buf[TPM_HEADER_SIZE],
390                                       expected - TPM_HEADER_SIZE);
391         if (size < expected) {
392                 debug("Unable to read remainder of result\n");
393                 return -ETIMEDOUT;
394         }
395
396         rc = tpm_tis_i2c_wait_for_stat(dev, TPM_STS_VALID, chip->timeout_c,
397                                        &status);
398         if (rc)
399                 return rc;
400         if (status & TPM_STS_DATA_AVAIL) {  /* Retry? */
401                 debug("Error left over data\n");
402                 return -EIO;
403         }
404
405         return size;
406 }
407
408 static int tpm_tis_i2c_send(struct udevice *dev, const u8 *buf, size_t len)
409 {
410         struct tpm_chip *chip = dev_get_priv(dev);
411         int rc, status;
412         size_t burstcnt;
413         size_t count = 0;
414         int retry = 0;
415         u8 sts = TPM_STS_GO;
416
417         debug("%s: len=%d\n", __func__, len);
418         if (len > TPM_DEV_BUFSIZE)
419                 return -E2BIG;  /* Command is too long for our tpm, sorry */
420
421         if (tpm_tis_i2c_request_locality(dev, 0) < 0)
422                 return -EBUSY;
423
424         status = tpm_tis_i2c_status(dev);
425         if ((status & TPM_STS_COMMAND_READY) == 0) {
426                 rc = tpm_tis_i2c_ready(dev);
427                 if (rc)
428                         return rc;
429                 rc = tpm_tis_i2c_wait_for_stat(dev, TPM_STS_COMMAND_READY,
430                                                chip->timeout_b, &status);
431                 if (rc)
432                         return rc;
433         }
434
435         burstcnt = tpm_tis_i2c_get_burstcount(dev);
436
437         /* burstcount < 0 -> tpm is busy */
438         if (burstcnt < 0)
439                 return burstcnt;
440
441         while (count < len) {
442                 udelay(300);
443                 if (burstcnt > len - count)
444                         burstcnt = len - count;
445
446 #ifdef CONFIG_TPM_TIS_I2C_BURST_LIMITATION
447                 if (retry && burstcnt > CONFIG_TPM_TIS_I2C_BURST_LIMITATION_LEN)
448                         burstcnt = CONFIG_TPM_TIS_I2C_BURST_LIMITATION_LEN;
449 #endif /* CONFIG_TPM_TIS_I2C_BURST_LIMITATION */
450
451                 rc = tpm_tis_i2c_write(dev, TPM_DATA_FIFO(chip->locality),
452                                        &(buf[count]), burstcnt);
453                 if (rc == 0)
454                         count += burstcnt;
455                 else {
456                         debug("%s: error\n", __func__);
457                         if (retry++ > 10)
458                                 return -EIO;
459                         rc = tpm_tis_i2c_wait_for_stat(dev, TPM_STS_VALID,
460                                                        chip->timeout_c,
461                                                        &status);
462                         if (rc)
463                                 return rc;
464
465                         if ((status & TPM_STS_DATA_EXPECT) == 0)
466                                 return -EIO;
467                 }
468         }
469
470         /* Go and do it */
471         rc = tpm_tis_i2c_write(dev, TPM_STS(chip->locality), &sts, 1);
472         if (rc < 0)
473                 return rc;
474         debug("%s: done, rc=%d\n", __func__, rc);
475
476         return len;
477 }
478
479 static int tpm_tis_i2c_cleanup(struct udevice *dev)
480 {
481         struct tpm_chip *chip = dev_get_priv(dev);
482
483         tpm_tis_i2c_ready(dev);
484         /*
485          * The TPM needs some time to clean up here,
486          * so we sleep rather than keeping the bus busy
487          */
488         mdelay(2);
489         tpm_tis_i2c_release_locality(dev, chip->locality, 0);
490
491         return 0;
492 }
493
494 static int tpm_tis_i2c_init(struct udevice *dev)
495 {
496         struct tpm_chip *chip = dev_get_priv(dev);
497         u32 vendor;
498         u32 expected_did_vid;
499         int rc;
500
501         chip->is_open = 1;
502
503         /* Default timeouts - these could move to the device tree */
504         chip->timeout_a = TIS_SHORT_TIMEOUT_MS;
505         chip->timeout_b = TIS_LONG_TIMEOUT_MS;
506         chip->timeout_c = TIS_SHORT_TIMEOUT_MS;
507         chip->timeout_d = TIS_SHORT_TIMEOUT_MS;
508
509         rc = tpm_tis_i2c_request_locality(dev, 0);
510         if (rc < 0)
511                 return rc;
512
513         /* Read four bytes from DID_VID register */
514         if (tpm_tis_i2c_read(dev, TPM_DID_VID(0), (uchar *)&vendor, 4) < 0) {
515                 tpm_tis_i2c_release_locality(dev, 0, 1);
516                 return -EIO;
517         }
518
519         if (chip->chip_type == SLB9635) {
520                 vendor = be32_to_cpu(vendor);
521                 expected_did_vid = TPM_TIS_I2C_DID_VID_9635;
522         } else {
523                 /* device id and byte order has changed for newer i2c tpms */
524                 expected_did_vid = TPM_TIS_I2C_DID_VID_9645;
525         }
526
527         if (chip->chip_type != UNKNOWN && vendor != expected_did_vid) {
528                 error("Vendor id did not match! ID was %08x\n", vendor);
529                 return -ENODEV;
530         }
531
532         chip->vend_dev = vendor;
533         debug("1.2 TPM (chip type %s device-id 0x%X)\n",
534               chip_name[chip->chip_type], vendor >> 16);
535
536         /*
537          * A timeout query to TPM can be placed here.
538          * Standard timeout values are used so far
539          */
540
541         return 0;
542 }
543
544 static int tpm_tis_i2c_open(struct udevice *dev)
545 {
546         struct tpm_chip *chip = dev_get_priv(dev);
547         int rc;
548
549         debug("%s: start\n", __func__);
550         if (chip->is_open)
551                 return -EBUSY;
552         rc = tpm_tis_i2c_init(dev);
553         if (rc < 0)
554                 chip->is_open = 0;
555
556         return rc;
557 }
558
559 static int tpm_tis_i2c_close(struct udevice *dev)
560 {
561         struct tpm_chip *chip = dev_get_priv(dev);
562
563         if (chip->is_open) {
564                 tpm_tis_i2c_release_locality(dev, chip->locality, 1);
565                 chip->is_open = 0;
566                 chip->vend_dev = 0;
567         }
568
569         return 0;
570 }
571
572 static int tpm_tis_get_desc(struct udevice *dev, char *buf, int size)
573 {
574         struct tpm_chip *chip = dev_get_priv(dev);
575
576         if (size < 50)
577                 return -ENOSPC;
578
579         return snprintf(buf, size, "1.2 TPM (%s, chip type %s device-id 0x%x)",
580                         chip->is_open ? "open" : "closed",
581                         chip_name[chip->chip_type],
582                         chip->vend_dev >> 16);
583 }
584
585 static int tpm_tis_i2c_probe(struct udevice *dev)
586 {
587         struct tpm_chip_priv *uc_priv = dev_get_uclass_priv(dev);
588         struct tpm_chip *chip = dev_get_priv(dev);
589
590         chip->chip_type = dev_get_driver_data(dev);
591
592         /* TODO: These need to be checked and tuned */
593         uc_priv->duration_ms[TPM_SHORT] = TIS_SHORT_TIMEOUT_MS;
594         uc_priv->duration_ms[TPM_MEDIUM] = TIS_LONG_TIMEOUT_MS;
595         uc_priv->duration_ms[TPM_LONG] = TIS_LONG_TIMEOUT_MS;
596         uc_priv->retry_time_ms = TPM_TIMEOUT_MS;
597
598         return 0;
599 }
600
601 static const struct tpm_ops tpm_tis_i2c_ops = {
602         .open           = tpm_tis_i2c_open,
603         .close          = tpm_tis_i2c_close,
604         .get_desc       = tpm_tis_get_desc,
605         .send           = tpm_tis_i2c_send,
606         .recv           = tpm_tis_i2c_recv,
607         .cleanup        = tpm_tis_i2c_cleanup,
608 };
609
610 static const struct udevice_id tpm_tis_i2c_ids[] = {
611         { .compatible = "infineon,slb9635tt", .data = SLB9635 },
612         { .compatible = "infineon,slb9645tt", .data = SLB9645 },
613         { }
614 };
615
616 U_BOOT_DRIVER(tpm_tis_i2c) = {
617         .name   = "tpm_tis_i2c",
618         .id     = UCLASS_TPM,
619         .of_match = tpm_tis_i2c_ids,
620         .ops    = &tpm_tis_i2c_ops,
621         .probe  = tpm_tis_i2c_probe,
622         .priv_auto_alloc_size = sizeof(struct tpm_chip),
623 };