Merge tag 'for-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux...
[linux-2.6-microblaze.git] / drivers / char / tpm / st33zp24 / st33zp24.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * STMicroelectronics TPM Linux driver for TPM ST33ZP24
4  * Copyright (C) 2009 - 2016 STMicroelectronics
5  */
6
7 #include <linux/module.h>
8 #include <linux/fs.h>
9 #include <linux/kernel.h>
10 #include <linux/delay.h>
11 #include <linux/wait.h>
12 #include <linux/freezer.h>
13 #include <linux/string.h>
14 #include <linux/interrupt.h>
15 #include <linux/gpio.h>
16 #include <linux/sched.h>
17 #include <linux/uaccess.h>
18 #include <linux/io.h>
19 #include <linux/slab.h>
20
21 #include "../tpm.h"
22 #include "st33zp24.h"
23
24 #define TPM_ACCESS                      0x0
25 #define TPM_STS                         0x18
26 #define TPM_DATA_FIFO                   0x24
27 #define TPM_INTF_CAPABILITY             0x14
28 #define TPM_INT_STATUS                  0x10
29 #define TPM_INT_ENABLE                  0x08
30
31 #define LOCALITY0                       0
32
33 enum st33zp24_access {
34         TPM_ACCESS_VALID = 0x80,
35         TPM_ACCESS_ACTIVE_LOCALITY = 0x20,
36         TPM_ACCESS_REQUEST_PENDING = 0x04,
37         TPM_ACCESS_REQUEST_USE = 0x02,
38 };
39
40 enum st33zp24_status {
41         TPM_STS_VALID = 0x80,
42         TPM_STS_COMMAND_READY = 0x40,
43         TPM_STS_GO = 0x20,
44         TPM_STS_DATA_AVAIL = 0x10,
45         TPM_STS_DATA_EXPECT = 0x08,
46 };
47
48 enum st33zp24_int_flags {
49         TPM_GLOBAL_INT_ENABLE = 0x80,
50         TPM_INTF_CMD_READY_INT = 0x080,
51         TPM_INTF_FIFO_AVALAIBLE_INT = 0x040,
52         TPM_INTF_WAKE_UP_READY_INT = 0x020,
53         TPM_INTF_LOCALITY_CHANGE_INT = 0x004,
54         TPM_INTF_STS_VALID_INT = 0x002,
55         TPM_INTF_DATA_AVAIL_INT = 0x001,
56 };
57
58 enum tis_defaults {
59         TIS_SHORT_TIMEOUT = 750,
60         TIS_LONG_TIMEOUT = 2000,
61 };
62
63 /*
64  * clear_interruption clear the pending interrupt.
65  * @param: tpm_dev, the tpm device device.
66  * @return: the interrupt status value.
67  */
68 static u8 clear_interruption(struct st33zp24_dev *tpm_dev)
69 {
70         u8 interrupt;
71
72         tpm_dev->ops->recv(tpm_dev->phy_id, TPM_INT_STATUS, &interrupt, 1);
73         tpm_dev->ops->send(tpm_dev->phy_id, TPM_INT_STATUS, &interrupt, 1);
74         return interrupt;
75 } /* clear_interruption() */
76
77 /*
78  * st33zp24_cancel, cancel the current command execution or
79  * set STS to COMMAND READY.
80  * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h
81  */
82 static void st33zp24_cancel(struct tpm_chip *chip)
83 {
84         struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
85         u8 data;
86
87         data = TPM_STS_COMMAND_READY;
88         tpm_dev->ops->send(tpm_dev->phy_id, TPM_STS, &data, 1);
89 } /* st33zp24_cancel() */
90
91 /*
92  * st33zp24_status return the TPM_STS register
93  * @param: chip, the tpm chip description
94  * @return: the TPM_STS register value.
95  */
96 static u8 st33zp24_status(struct tpm_chip *chip)
97 {
98         struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
99         u8 data;
100
101         tpm_dev->ops->recv(tpm_dev->phy_id, TPM_STS, &data, 1);
102         return data;
103 } /* st33zp24_status() */
104
105 /*
106  * check_locality if the locality is active
107  * @param: chip, the tpm chip description
108  * @return: true if LOCALITY0 is active, otherwise false
109  */
110 static bool check_locality(struct tpm_chip *chip)
111 {
112         struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
113         u8 data;
114         u8 status;
115
116         status = tpm_dev->ops->recv(tpm_dev->phy_id, TPM_ACCESS, &data, 1);
117         if (status && (data &
118                 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
119                 (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
120                 return true;
121
122         return false;
123 } /* check_locality() */
124
125 /*
126  * request_locality request the TPM locality
127  * @param: chip, the chip description
128  * @return: the active locality or negative value.
129  */
130 static int request_locality(struct tpm_chip *chip)
131 {
132         struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
133         unsigned long stop;
134         long ret;
135         u8 data;
136
137         if (check_locality(chip))
138                 return tpm_dev->locality;
139
140         data = TPM_ACCESS_REQUEST_USE;
141         ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_ACCESS, &data, 1);
142         if (ret < 0)
143                 return ret;
144
145         stop = jiffies + chip->timeout_a;
146
147         /* Request locality is usually effective after the request */
148         do {
149                 if (check_locality(chip))
150                         return tpm_dev->locality;
151                 msleep(TPM_TIMEOUT);
152         } while (time_before(jiffies, stop));
153
154         /* could not get locality */
155         return -EACCES;
156 } /* request_locality() */
157
158 /*
159  * release_locality release the active locality
160  * @param: chip, the tpm chip description.
161  */
162 static void release_locality(struct tpm_chip *chip)
163 {
164         struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
165         u8 data;
166
167         data = TPM_ACCESS_ACTIVE_LOCALITY;
168
169         tpm_dev->ops->send(tpm_dev->phy_id, TPM_ACCESS, &data, 1);
170 }
171
172 /*
173  * get_burstcount return the burstcount value
174  * @param: chip, the chip description
175  * return: the burstcount or negative value.
176  */
177 static int get_burstcount(struct tpm_chip *chip)
178 {
179         struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
180         unsigned long stop;
181         int burstcnt, status;
182         u8 temp;
183
184         stop = jiffies + chip->timeout_d;
185         do {
186                 status = tpm_dev->ops->recv(tpm_dev->phy_id, TPM_STS + 1,
187                                             &temp, 1);
188                 if (status < 0)
189                         return -EBUSY;
190
191                 burstcnt = temp;
192                 status = tpm_dev->ops->recv(tpm_dev->phy_id, TPM_STS + 2,
193                                             &temp, 1);
194                 if (status < 0)
195                         return -EBUSY;
196
197                 burstcnt |= temp << 8;
198                 if (burstcnt)
199                         return burstcnt;
200                 msleep(TPM_TIMEOUT);
201         } while (time_before(jiffies, stop));
202         return -EBUSY;
203 } /* get_burstcount() */
204
205
206 /*
207  * wait_for_tpm_stat_cond
208  * @param: chip, chip description
209  * @param: mask, expected mask value
210  * @param: check_cancel, does the command expected to be canceled ?
211  * @param: canceled, did we received a cancel request ?
212  * @return: true if status == mask or if the command is canceled.
213  * false in other cases.
214  */
215 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
216                                 bool check_cancel, bool *canceled)
217 {
218         u8 status = chip->ops->status(chip);
219
220         *canceled = false;
221         if ((status & mask) == mask)
222                 return true;
223         if (check_cancel && chip->ops->req_canceled(chip, status)) {
224                 *canceled = true;
225                 return true;
226         }
227         return false;
228 }
229
230 /*
231  * wait_for_stat wait for a TPM_STS value
232  * @param: chip, the tpm chip description
233  * @param: mask, the value mask to wait
234  * @param: timeout, the timeout
235  * @param: queue, the wait queue.
236  * @param: check_cancel, does the command can be cancelled ?
237  * @return: the tpm status, 0 if success, -ETIME if timeout is reached.
238  */
239 static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
240                         wait_queue_head_t *queue, bool check_cancel)
241 {
242         struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
243         unsigned long stop;
244         int ret = 0;
245         bool canceled = false;
246         bool condition;
247         u32 cur_intrs;
248         u8 status;
249
250         /* check current status */
251         status = st33zp24_status(chip);
252         if ((status & mask) == mask)
253                 return 0;
254
255         stop = jiffies + timeout;
256
257         if (chip->flags & TPM_CHIP_FLAG_IRQ) {
258                 cur_intrs = tpm_dev->intrs;
259                 clear_interruption(tpm_dev);
260                 enable_irq(tpm_dev->irq);
261
262                 do {
263                         if (ret == -ERESTARTSYS && freezing(current))
264                                 clear_thread_flag(TIF_SIGPENDING);
265
266                         timeout = stop - jiffies;
267                         if ((long) timeout <= 0)
268                                 return -1;
269
270                         ret = wait_event_interruptible_timeout(*queue,
271                                                 cur_intrs != tpm_dev->intrs,
272                                                 timeout);
273                         clear_interruption(tpm_dev);
274                         condition = wait_for_tpm_stat_cond(chip, mask,
275                                                 check_cancel, &canceled);
276                         if (ret >= 0 && condition) {
277                                 if (canceled)
278                                         return -ECANCELED;
279                                 return 0;
280                         }
281                 } while (ret == -ERESTARTSYS && freezing(current));
282
283                 disable_irq_nosync(tpm_dev->irq);
284
285         } else {
286                 do {
287                         msleep(TPM_TIMEOUT);
288                         status = chip->ops->status(chip);
289                         if ((status & mask) == mask)
290                                 return 0;
291                 } while (time_before(jiffies, stop));
292         }
293
294         return -ETIME;
295 } /* wait_for_stat() */
296
297 /*
298  * recv_data receive data
299  * @param: chip, the tpm chip description
300  * @param: buf, the buffer where the data are received
301  * @param: count, the number of data to receive
302  * @return: the number of bytes read from TPM FIFO.
303  */
304 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
305 {
306         struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
307         int size = 0, burstcnt, len, ret;
308
309         while (size < count &&
310                wait_for_stat(chip,
311                              TPM_STS_DATA_AVAIL | TPM_STS_VALID,
312                              chip->timeout_c,
313                              &tpm_dev->read_queue, true) == 0) {
314                 burstcnt = get_burstcount(chip);
315                 if (burstcnt < 0)
316                         return burstcnt;
317                 len = min_t(int, burstcnt, count - size);
318                 ret = tpm_dev->ops->recv(tpm_dev->phy_id, TPM_DATA_FIFO,
319                                          buf + size, len);
320                 if (ret < 0)
321                         return ret;
322
323                 size += len;
324         }
325         return size;
326 }
327
328 /*
329  * tpm_ioserirq_handler the serirq irq handler
330  * @param: irq, the tpm chip description
331  * @param: dev_id, the description of the chip
332  * @return: the status of the handler.
333  */
334 static irqreturn_t tpm_ioserirq_handler(int irq, void *dev_id)
335 {
336         struct tpm_chip *chip = dev_id;
337         struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
338
339         tpm_dev->intrs++;
340         wake_up_interruptible(&tpm_dev->read_queue);
341         disable_irq_nosync(tpm_dev->irq);
342
343         return IRQ_HANDLED;
344 } /* tpm_ioserirq_handler() */
345
346 /*
347  * st33zp24_send send TPM commands through the I2C bus.
348  *
349  * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h
350  * @param: buf, the buffer to send.
351  * @param: count, the number of bytes to send.
352  * @return: In case of success the number of bytes sent.
353  *                      In other case, a < 0 value describing the issue.
354  */
355 static int st33zp24_send(struct tpm_chip *chip, unsigned char *buf,
356                          size_t len)
357 {
358         struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
359         u32 status, i, size, ordinal;
360         int burstcnt = 0;
361         int ret;
362         u8 data;
363
364         if (len < TPM_HEADER_SIZE)
365                 return -EBUSY;
366
367         ret = request_locality(chip);
368         if (ret < 0)
369                 return ret;
370
371         status = st33zp24_status(chip);
372         if ((status & TPM_STS_COMMAND_READY) == 0) {
373                 st33zp24_cancel(chip);
374                 if (wait_for_stat
375                     (chip, TPM_STS_COMMAND_READY, chip->timeout_b,
376                      &tpm_dev->read_queue, false) < 0) {
377                         ret = -ETIME;
378                         goto out_err;
379                 }
380         }
381
382         for (i = 0; i < len - 1;) {
383                 burstcnt = get_burstcount(chip);
384                 if (burstcnt < 0)
385                         return burstcnt;
386                 size = min_t(int, len - i - 1, burstcnt);
387                 ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_DATA_FIFO,
388                                          buf + i, size);
389                 if (ret < 0)
390                         goto out_err;
391
392                 i += size;
393         }
394
395         status = st33zp24_status(chip);
396         if ((status & TPM_STS_DATA_EXPECT) == 0) {
397                 ret = -EIO;
398                 goto out_err;
399         }
400
401         ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_DATA_FIFO,
402                                  buf + len - 1, 1);
403         if (ret < 0)
404                 goto out_err;
405
406         status = st33zp24_status(chip);
407         if ((status & TPM_STS_DATA_EXPECT) != 0) {
408                 ret = -EIO;
409                 goto out_err;
410         }
411
412         data = TPM_STS_GO;
413         ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_STS, &data, 1);
414         if (ret < 0)
415                 goto out_err;
416
417         if (chip->flags & TPM_CHIP_FLAG_IRQ) {
418                 ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
419
420                 ret = wait_for_stat(chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID,
421                                 tpm_calc_ordinal_duration(chip, ordinal),
422                                 &tpm_dev->read_queue, false);
423                 if (ret < 0)
424                         goto out_err;
425         }
426
427         return 0;
428 out_err:
429         st33zp24_cancel(chip);
430         release_locality(chip);
431         return ret;
432 }
433
434 /*
435  * st33zp24_recv received TPM response through TPM phy.
436  * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h.
437  * @param: buf, the buffer to store datas.
438  * @param: count, the number of bytes to send.
439  * @return: In case of success the number of bytes received.
440  *          In other case, a < 0 value describing the issue.
441  */
442 static int st33zp24_recv(struct tpm_chip *chip, unsigned char *buf,
443                             size_t count)
444 {
445         int size = 0;
446         u32 expected;
447
448         if (!chip)
449                 return -EBUSY;
450
451         if (count < TPM_HEADER_SIZE) {
452                 size = -EIO;
453                 goto out;
454         }
455
456         size = recv_data(chip, buf, TPM_HEADER_SIZE);
457         if (size < TPM_HEADER_SIZE) {
458                 dev_err(&chip->dev, "Unable to read header\n");
459                 goto out;
460         }
461
462         expected = be32_to_cpu(*(__be32 *)(buf + 2));
463         if (expected > count || expected < TPM_HEADER_SIZE) {
464                 size = -EIO;
465                 goto out;
466         }
467
468         size += recv_data(chip, &buf[TPM_HEADER_SIZE],
469                         expected - TPM_HEADER_SIZE);
470         if (size < expected) {
471                 dev_err(&chip->dev, "Unable to read remainder of result\n");
472                 size = -ETIME;
473         }
474
475 out:
476         st33zp24_cancel(chip);
477         release_locality(chip);
478         return size;
479 }
480
481 /*
482  * st33zp24_req_canceled
483  * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h.
484  * @param: status, the TPM status.
485  * @return: Does TPM ready to compute a new command ? true.
486  */
487 static bool st33zp24_req_canceled(struct tpm_chip *chip, u8 status)
488 {
489         return (status == TPM_STS_COMMAND_READY);
490 }
491
492 static const struct tpm_class_ops st33zp24_tpm = {
493         .flags = TPM_OPS_AUTO_STARTUP,
494         .send = st33zp24_send,
495         .recv = st33zp24_recv,
496         .cancel = st33zp24_cancel,
497         .status = st33zp24_status,
498         .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
499         .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
500         .req_canceled = st33zp24_req_canceled,
501 };
502
503 /*
504  * st33zp24_probe initialize the TPM device
505  * @param: client, the i2c_client description (TPM I2C description).
506  * @param: id, the i2c_device_id struct.
507  * @return: 0 in case of success.
508  *       -1 in other case.
509  */
510 int st33zp24_probe(void *phy_id, const struct st33zp24_phy_ops *ops,
511                    struct device *dev, int irq, int io_lpcpd)
512 {
513         int ret;
514         u8 intmask = 0;
515         struct tpm_chip *chip;
516         struct st33zp24_dev *tpm_dev;
517
518         chip = tpmm_chip_alloc(dev, &st33zp24_tpm);
519         if (IS_ERR(chip))
520                 return PTR_ERR(chip);
521
522         tpm_dev = devm_kzalloc(dev, sizeof(struct st33zp24_dev),
523                                GFP_KERNEL);
524         if (!tpm_dev)
525                 return -ENOMEM;
526
527         tpm_dev->phy_id = phy_id;
528         tpm_dev->ops = ops;
529         dev_set_drvdata(&chip->dev, tpm_dev);
530
531         chip->timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
532         chip->timeout_b = msecs_to_jiffies(TIS_LONG_TIMEOUT);
533         chip->timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
534         chip->timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
535
536         tpm_dev->locality = LOCALITY0;
537
538         if (irq) {
539                 /* INTERRUPT Setup */
540                 init_waitqueue_head(&tpm_dev->read_queue);
541                 tpm_dev->intrs = 0;
542
543                 if (request_locality(chip) != LOCALITY0) {
544                         ret = -ENODEV;
545                         goto _tpm_clean_answer;
546                 }
547
548                 clear_interruption(tpm_dev);
549                 ret = devm_request_irq(dev, irq, tpm_ioserirq_handler,
550                                 IRQF_TRIGGER_HIGH, "TPM SERIRQ management",
551                                 chip);
552                 if (ret < 0) {
553                         dev_err(&chip->dev, "TPM SERIRQ signals %d not available\n",
554                                 irq);
555                         goto _tpm_clean_answer;
556                 }
557
558                 intmask |= TPM_INTF_CMD_READY_INT
559                         |  TPM_INTF_STS_VALID_INT
560                         |  TPM_INTF_DATA_AVAIL_INT;
561
562                 ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_INT_ENABLE,
563                                          &intmask, 1);
564                 if (ret < 0)
565                         goto _tpm_clean_answer;
566
567                 intmask = TPM_GLOBAL_INT_ENABLE;
568                 ret = tpm_dev->ops->send(tpm_dev->phy_id, (TPM_INT_ENABLE + 3),
569                                          &intmask, 1);
570                 if (ret < 0)
571                         goto _tpm_clean_answer;
572
573                 tpm_dev->irq = irq;
574                 chip->flags |= TPM_CHIP_FLAG_IRQ;
575
576                 disable_irq_nosync(tpm_dev->irq);
577         }
578
579         return tpm_chip_register(chip);
580 _tpm_clean_answer:
581         dev_info(&chip->dev, "TPM initialization fail\n");
582         return ret;
583 }
584 EXPORT_SYMBOL(st33zp24_probe);
585
586 /*
587  * st33zp24_remove remove the TPM device
588  * @param: tpm_data, the tpm phy.
589  * @return: 0 in case of success.
590  */
591 int st33zp24_remove(struct tpm_chip *chip)
592 {
593         tpm_chip_unregister(chip);
594         return 0;
595 }
596 EXPORT_SYMBOL(st33zp24_remove);
597
598 #ifdef CONFIG_PM_SLEEP
599 /*
600  * st33zp24_pm_suspend suspend the TPM device
601  * @param: tpm_data, the tpm phy.
602  * @param: mesg, the power management message.
603  * @return: 0 in case of success.
604  */
605 int st33zp24_pm_suspend(struct device *dev)
606 {
607         struct tpm_chip *chip = dev_get_drvdata(dev);
608         struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
609
610         int ret = 0;
611
612         if (gpio_is_valid(tpm_dev->io_lpcpd))
613                 gpio_set_value(tpm_dev->io_lpcpd, 0);
614         else
615                 ret = tpm_pm_suspend(dev);
616
617         return ret;
618 } /* st33zp24_pm_suspend() */
619 EXPORT_SYMBOL(st33zp24_pm_suspend);
620
621 /*
622  * st33zp24_pm_resume resume the TPM device
623  * @param: tpm_data, the tpm phy.
624  * @return: 0 in case of success.
625  */
626 int st33zp24_pm_resume(struct device *dev)
627 {
628         struct tpm_chip *chip = dev_get_drvdata(dev);
629         struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
630         int ret = 0;
631
632         if (gpio_is_valid(tpm_dev->io_lpcpd)) {
633                 gpio_set_value(tpm_dev->io_lpcpd, 1);
634                 ret = wait_for_stat(chip,
635                                 TPM_STS_VALID, chip->timeout_b,
636                                 &tpm_dev->read_queue, false);
637         } else {
638                 ret = tpm_pm_resume(dev);
639                 if (!ret)
640                         tpm1_do_selftest(chip);
641         }
642         return ret;
643 } /* st33zp24_pm_resume() */
644 EXPORT_SYMBOL(st33zp24_pm_resume);
645 #endif
646
647 MODULE_AUTHOR("TPM support (TPMsupport@list.st.com)");
648 MODULE_DESCRIPTION("ST33ZP24 TPM 1.2 driver");
649 MODULE_VERSION("1.3.0");
650 MODULE_LICENSE("GPL");