blob: 847f1597fe9b283557e45f5598da955a2dbb7f8f [file] [log] [blame]
Jason Gunthorpe4c336e42013-10-06 12:43:13 -06001/******************************************************************************
2 * Nuvoton TPM I2C Device Driver Interface for WPCT301/NPCT501,
3 * based on the TCG TPM Interface Spec version 1.2.
4 * Specifications at www.trustedcomputinggroup.org
5 *
6 * Copyright (C) 2011, Nuvoton Technology Corporation.
7 * Dan Morav <dan.morav@nuvoton.com>
8 * Copyright (C) 2013, Obsidian Research Corp.
9 * Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
10 *
11 * This program is free software: you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation, either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program. If not, see http://www.gnu.org/licenses/>.
23 *
24 * Nuvoton contact information: APC.Support@nuvoton.com
25 *****************************************************************************/
26
27#include <linux/init.h>
28#include <linux/module.h>
29#include <linux/moduleparam.h>
30#include <linux/slab.h>
31#include <linux/interrupt.h>
32#include <linux/wait.h>
33#include <linux/i2c.h>
34#include "tpm.h"
35
36/* I2C interface offsets */
37#define TPM_STS 0x00
38#define TPM_BURST_COUNT 0x01
39#define TPM_DATA_FIFO_W 0x20
40#define TPM_DATA_FIFO_R 0x40
41#define TPM_VID_DID_RID 0x60
42/* TPM command header size */
43#define TPM_HEADER_SIZE 10
44#define TPM_RETRY 5
45/*
46 * I2C bus device maximum buffer size w/o counting I2C address or command
47 * i.e. max size required for I2C write is 34 = addr, command, 32 bytes data
48 */
49#define TPM_I2C_MAX_BUF_SIZE 32
50#define TPM_I2C_RETRY_COUNT 32
51#define TPM_I2C_BUS_DELAY 1 /* msec */
52#define TPM_I2C_RETRY_DELAY_SHORT 2 /* msec */
53#define TPM_I2C_RETRY_DELAY_LONG 10 /* msec */
54
55#define I2C_DRIVER_NAME "tpm_i2c_nuvoton"
56
57struct priv_data {
58 unsigned int intrs;
59};
60
61static s32 i2c_nuvoton_read_buf(struct i2c_client *client, u8 offset, u8 size,
62 u8 *data)
63{
64 s32 status;
65
66 status = i2c_smbus_read_i2c_block_data(client, offset, size, data);
67 dev_dbg(&client->dev,
68 "%s(offset=%u size=%u data=%*ph) -> sts=%d\n", __func__,
69 offset, size, (int)size, data, status);
70 return status;
71}
72
73static s32 i2c_nuvoton_write_buf(struct i2c_client *client, u8 offset, u8 size,
74 u8 *data)
75{
76 s32 status;
77
78 status = i2c_smbus_write_i2c_block_data(client, offset, size, data);
79 dev_dbg(&client->dev,
80 "%s(offset=%u size=%u data=%*ph) -> sts=%d\n", __func__,
81 offset, size, (int)size, data, status);
82 return status;
83}
84
85#define TPM_STS_VALID 0x80
86#define TPM_STS_COMMAND_READY 0x40
87#define TPM_STS_GO 0x20
88#define TPM_STS_DATA_AVAIL 0x10
89#define TPM_STS_EXPECT 0x08
90#define TPM_STS_RESPONSE_RETRY 0x02
91#define TPM_STS_ERR_VAL 0x07 /* bit2...bit0 reads always 0 */
92
93#define TPM_I2C_SHORT_TIMEOUT 750 /* ms */
94#define TPM_I2C_LONG_TIMEOUT 2000 /* 2 sec */
95
96/* read TPM_STS register */
97static u8 i2c_nuvoton_read_status(struct tpm_chip *chip)
98{
Jarkko Sakkinen71ed8482014-12-12 11:46:36 -080099 struct i2c_client *client = to_i2c_client(chip->pdev);
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600100 s32 status;
101 u8 data;
102
103 status = i2c_nuvoton_read_buf(client, TPM_STS, 1, &data);
104 if (status <= 0) {
Jarkko Sakkinen71ed8482014-12-12 11:46:36 -0800105 dev_err(chip->pdev, "%s() error return %d\n", __func__,
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600106 status);
107 data = TPM_STS_ERR_VAL;
108 }
109
110 return data;
111}
112
113/* write byte to TPM_STS register */
114static s32 i2c_nuvoton_write_status(struct i2c_client *client, u8 data)
115{
116 s32 status;
117 int i;
118
119 /* this causes the current command to be aborted */
120 for (i = 0, status = -1; i < TPM_I2C_RETRY_COUNT && status < 0; i++) {
121 status = i2c_nuvoton_write_buf(client, TPM_STS, 1, &data);
122 msleep(TPM_I2C_BUS_DELAY);
123 }
124 return status;
125}
126
127/* write commandReady to TPM_STS register */
128static void i2c_nuvoton_ready(struct tpm_chip *chip)
129{
Jarkko Sakkinen71ed8482014-12-12 11:46:36 -0800130 struct i2c_client *client = to_i2c_client(chip->pdev);
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600131 s32 status;
132
133 /* this causes the current command to be aborted */
134 status = i2c_nuvoton_write_status(client, TPM_STS_COMMAND_READY);
135 if (status < 0)
Jarkko Sakkinen71ed8482014-12-12 11:46:36 -0800136 dev_err(chip->pdev,
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600137 "%s() fail to write TPM_STS.commandReady\n", __func__);
138}
139
140/* read burstCount field from TPM_STS register
141 * return -1 on fail to read */
142static int i2c_nuvoton_get_burstcount(struct i2c_client *client,
143 struct tpm_chip *chip)
144{
145 unsigned long stop = jiffies + chip->vendor.timeout_d;
146 s32 status;
147 int burst_count = -1;
148 u8 data;
149
150 /* wait for burstcount to be non-zero */
151 do {
152 /* in I2C burstCount is 1 byte */
153 status = i2c_nuvoton_read_buf(client, TPM_BURST_COUNT, 1,
154 &data);
155 if (status > 0 && data > 0) {
156 burst_count = min_t(u8, TPM_I2C_MAX_BUF_SIZE, data);
157 break;
158 }
159 msleep(TPM_I2C_BUS_DELAY);
160 } while (time_before(jiffies, stop));
161
162 return burst_count;
163}
164
165/*
166 * WPCT301/NPCT501 SINT# supports only dataAvail
167 * any call to this function which is not waiting for dataAvail will
168 * set queue to NULL to avoid waiting for interrupt
169 */
170static bool i2c_nuvoton_check_status(struct tpm_chip *chip, u8 mask, u8 value)
171{
172 u8 status = i2c_nuvoton_read_status(chip);
173 return (status != TPM_STS_ERR_VAL) && ((status & mask) == value);
174}
175
176static int i2c_nuvoton_wait_for_stat(struct tpm_chip *chip, u8 mask, u8 value,
177 u32 timeout, wait_queue_head_t *queue)
178{
179 if (chip->vendor.irq && queue) {
180 s32 rc;
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600181 struct priv_data *priv = chip->vendor.priv;
182 unsigned int cur_intrs = priv->intrs;
183
184 enable_irq(chip->vendor.irq);
185 rc = wait_event_interruptible_timeout(*queue,
186 cur_intrs != priv->intrs,
187 timeout);
188 if (rc > 0)
189 return 0;
190 /* At this point we know that the SINT pin is asserted, so we
191 * do not need to do i2c_nuvoton_check_status */
192 } else {
193 unsigned long ten_msec, stop;
194 bool status_valid;
195
196 /* check current status */
197 status_valid = i2c_nuvoton_check_status(chip, mask, value);
198 if (status_valid)
199 return 0;
200
201 /* use polling to wait for the event */
202 ten_msec = jiffies + msecs_to_jiffies(TPM_I2C_RETRY_DELAY_LONG);
203 stop = jiffies + timeout;
204 do {
205 if (time_before(jiffies, ten_msec))
206 msleep(TPM_I2C_RETRY_DELAY_SHORT);
207 else
208 msleep(TPM_I2C_RETRY_DELAY_LONG);
209 status_valid = i2c_nuvoton_check_status(chip, mask,
210 value);
211 if (status_valid)
212 return 0;
213 } while (time_before(jiffies, stop));
214 }
Jarkko Sakkinen71ed8482014-12-12 11:46:36 -0800215 dev_err(chip->pdev, "%s(%02x, %02x) -> timeout\n", __func__, mask,
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600216 value);
217 return -ETIMEDOUT;
218}
219
220/* wait for dataAvail field to be set in the TPM_STS register */
221static int i2c_nuvoton_wait_for_data_avail(struct tpm_chip *chip, u32 timeout,
222 wait_queue_head_t *queue)
223{
224 return i2c_nuvoton_wait_for_stat(chip,
225 TPM_STS_DATA_AVAIL | TPM_STS_VALID,
226 TPM_STS_DATA_AVAIL | TPM_STS_VALID,
227 timeout, queue);
228}
229
230/* Read @count bytes into @buf from TPM_RD_FIFO register */
231static int i2c_nuvoton_recv_data(struct i2c_client *client,
232 struct tpm_chip *chip, u8 *buf, size_t count)
233{
234 s32 rc;
235 int burst_count, bytes2read, size = 0;
236
237 while (size < count &&
238 i2c_nuvoton_wait_for_data_avail(chip,
239 chip->vendor.timeout_c,
240 &chip->vendor.read_queue) == 0) {
241 burst_count = i2c_nuvoton_get_burstcount(client, chip);
242 if (burst_count < 0) {
Jarkko Sakkinen71ed8482014-12-12 11:46:36 -0800243 dev_err(chip->pdev,
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600244 "%s() fail to read burstCount=%d\n", __func__,
245 burst_count);
246 return -EIO;
247 }
248 bytes2read = min_t(size_t, burst_count, count - size);
249 rc = i2c_nuvoton_read_buf(client, TPM_DATA_FIFO_R,
250 bytes2read, &buf[size]);
251 if (rc < 0) {
Jarkko Sakkinen71ed8482014-12-12 11:46:36 -0800252 dev_err(chip->pdev,
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600253 "%s() fail on i2c_nuvoton_read_buf()=%d\n",
254 __func__, rc);
255 return -EIO;
256 }
Jarkko Sakkinen71ed8482014-12-12 11:46:36 -0800257 dev_dbg(chip->pdev, "%s(%d):", __func__, bytes2read);
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600258 size += bytes2read;
259 }
260
261 return size;
262}
263
264/* Read TPM command results */
265static int i2c_nuvoton_recv(struct tpm_chip *chip, u8 *buf, size_t count)
266{
Jarkko Sakkinen71ed8482014-12-12 11:46:36 -0800267 struct device *dev = chip->pdev;
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600268 struct i2c_client *client = to_i2c_client(dev);
269 s32 rc;
270 int expected, status, burst_count, retries, size = 0;
271
272 if (count < TPM_HEADER_SIZE) {
273 i2c_nuvoton_ready(chip); /* return to idle */
274 dev_err(dev, "%s() count < header size\n", __func__);
275 return -EIO;
276 }
277 for (retries = 0; retries < TPM_RETRY; retries++) {
278 if (retries > 0) {
279 /* if this is not the first trial, set responseRetry */
280 i2c_nuvoton_write_status(client,
281 TPM_STS_RESPONSE_RETRY);
282 }
283 /*
284 * read first available (> 10 bytes), including:
285 * tag, paramsize, and result
286 */
287 status = i2c_nuvoton_wait_for_data_avail(
288 chip, chip->vendor.timeout_c, &chip->vendor.read_queue);
289 if (status != 0) {
290 dev_err(dev, "%s() timeout on dataAvail\n", __func__);
291 size = -ETIMEDOUT;
292 continue;
293 }
294 burst_count = i2c_nuvoton_get_burstcount(client, chip);
295 if (burst_count < 0) {
296 dev_err(dev, "%s() fail to get burstCount\n", __func__);
297 size = -EIO;
298 continue;
299 }
300 size = i2c_nuvoton_recv_data(client, chip, buf,
301 burst_count);
302 if (size < TPM_HEADER_SIZE) {
303 dev_err(dev, "%s() fail to read header\n", __func__);
304 size = -EIO;
305 continue;
306 }
307 /*
308 * convert number of expected bytes field from big endian 32 bit
309 * to machine native
310 */
311 expected = be32_to_cpu(*(__be32 *) (buf + 2));
312 if (expected > count) {
313 dev_err(dev, "%s() expected > count\n", __func__);
314 size = -EIO;
315 continue;
316 }
317 rc = i2c_nuvoton_recv_data(client, chip, &buf[size],
318 expected - size);
319 size += rc;
320 if (rc < 0 || size < expected) {
321 dev_err(dev, "%s() fail to read remainder of result\n",
322 __func__);
323 size = -EIO;
324 continue;
325 }
326 if (i2c_nuvoton_wait_for_stat(
327 chip, TPM_STS_VALID | TPM_STS_DATA_AVAIL,
328 TPM_STS_VALID, chip->vendor.timeout_c,
329 NULL)) {
330 dev_err(dev, "%s() error left over data\n", __func__);
331 size = -ETIMEDOUT;
332 continue;
333 }
334 break;
335 }
336 i2c_nuvoton_ready(chip);
Jarkko Sakkinen71ed8482014-12-12 11:46:36 -0800337 dev_dbg(chip->pdev, "%s() -> %d\n", __func__, size);
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600338 return size;
339}
340
341/*
342 * Send TPM command.
343 *
344 * If interrupts are used (signaled by an irq set in the vendor structure)
345 * tpm.c can skip polling for the data to be available as the interrupt is
346 * waited for here
347 */
348static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len)
349{
Jarkko Sakkinen71ed8482014-12-12 11:46:36 -0800350 struct device *dev = chip->pdev;
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600351 struct i2c_client *client = to_i2c_client(dev);
352 u32 ordinal;
353 size_t count = 0;
354 int burst_count, bytes2write, retries, rc = -EIO;
355
356 for (retries = 0; retries < TPM_RETRY; retries++) {
357 i2c_nuvoton_ready(chip);
358 if (i2c_nuvoton_wait_for_stat(chip, TPM_STS_COMMAND_READY,
359 TPM_STS_COMMAND_READY,
360 chip->vendor.timeout_b, NULL)) {
361 dev_err(dev, "%s() timeout on commandReady\n",
362 __func__);
363 rc = -EIO;
364 continue;
365 }
366 rc = 0;
367 while (count < len - 1) {
368 burst_count = i2c_nuvoton_get_burstcount(client,
369 chip);
370 if (burst_count < 0) {
371 dev_err(dev, "%s() fail get burstCount\n",
372 __func__);
373 rc = -EIO;
374 break;
375 }
376 bytes2write = min_t(size_t, burst_count,
377 len - 1 - count);
378 rc = i2c_nuvoton_write_buf(client, TPM_DATA_FIFO_W,
379 bytes2write, &buf[count]);
380 if (rc < 0) {
381 dev_err(dev, "%s() fail i2cWriteBuf\n",
382 __func__);
383 break;
384 }
385 dev_dbg(dev, "%s(%d):", __func__, bytes2write);
386 count += bytes2write;
387 rc = i2c_nuvoton_wait_for_stat(chip,
388 TPM_STS_VALID |
389 TPM_STS_EXPECT,
390 TPM_STS_VALID |
391 TPM_STS_EXPECT,
392 chip->vendor.timeout_c,
393 NULL);
394 if (rc < 0) {
395 dev_err(dev, "%s() timeout on Expect\n",
396 __func__);
397 rc = -ETIMEDOUT;
398 break;
399 }
400 }
401 if (rc < 0)
402 continue;
403
404 /* write last byte */
405 rc = i2c_nuvoton_write_buf(client, TPM_DATA_FIFO_W, 1,
406 &buf[count]);
407 if (rc < 0) {
408 dev_err(dev, "%s() fail to write last byte\n",
409 __func__);
410 rc = -EIO;
411 continue;
412 }
413 dev_dbg(dev, "%s(last): %02x", __func__, buf[count]);
414 rc = i2c_nuvoton_wait_for_stat(chip,
415 TPM_STS_VALID | TPM_STS_EXPECT,
416 TPM_STS_VALID,
417 chip->vendor.timeout_c, NULL);
418 if (rc) {
419 dev_err(dev, "%s() timeout on Expect to clear\n",
420 __func__);
421 rc = -ETIMEDOUT;
422 continue;
423 }
424 break;
425 }
426 if (rc < 0) {
427 /* retries == TPM_RETRY */
428 i2c_nuvoton_ready(chip);
429 return rc;
430 }
431 /* execute the TPM command */
432 rc = i2c_nuvoton_write_status(client, TPM_STS_GO);
433 if (rc < 0) {
434 dev_err(dev, "%s() fail to write Go\n", __func__);
435 i2c_nuvoton_ready(chip);
436 return rc;
437 }
438 ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
439 rc = i2c_nuvoton_wait_for_data_avail(chip,
440 tpm_calc_ordinal_duration(chip,
441 ordinal),
442 &chip->vendor.read_queue);
443 if (rc) {
444 dev_err(dev, "%s() timeout command duration\n", __func__);
445 i2c_nuvoton_ready(chip);
446 return rc;
447 }
448
449 dev_dbg(dev, "%s() -> %zd\n", __func__, len);
450 return len;
451}
452
453static bool i2c_nuvoton_req_canceled(struct tpm_chip *chip, u8 status)
454{
455 return (status == TPM_STS_COMMAND_READY);
456}
457
Jason Gunthorpe01ad1fa2013-11-26 13:30:43 -0700458static const struct tpm_class_ops tpm_i2c = {
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600459 .status = i2c_nuvoton_read_status,
460 .recv = i2c_nuvoton_recv,
461 .send = i2c_nuvoton_send,
462 .cancel = i2c_nuvoton_ready,
463 .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
464 .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
465 .req_canceled = i2c_nuvoton_req_canceled,
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600466};
467
468/* The only purpose for the handler is to signal to any waiting threads that
469 * the interrupt is currently being asserted. The driver does not do any
470 * processing triggered by interrupts, and the chip provides no way to mask at
471 * the source (plus that would be slow over I2C). Run the IRQ as a one-shot,
472 * this means it cannot be shared. */
473static irqreturn_t i2c_nuvoton_int_handler(int dummy, void *dev_id)
474{
475 struct tpm_chip *chip = dev_id;
476 struct priv_data *priv = chip->vendor.priv;
477
478 priv->intrs++;
479 wake_up(&chip->vendor.read_queue);
480 disable_irq_nosync(chip->vendor.irq);
481 return IRQ_HANDLED;
482}
483
484static int get_vid(struct i2c_client *client, u32 *res)
485{
486 static const u8 vid_did_rid_value[] = { 0x50, 0x10, 0xfe };
487 u32 temp;
488 s32 rc;
489
490 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
491 return -ENODEV;
492 rc = i2c_nuvoton_read_buf(client, TPM_VID_DID_RID, 4, (u8 *)&temp);
493 if (rc < 0)
494 return rc;
495
496 /* check WPCT301 values - ignore RID */
497 if (memcmp(&temp, vid_did_rid_value, sizeof(vid_did_rid_value))) {
498 /*
499 * f/w rev 2.81 has an issue where the VID_DID_RID is not
500 * reporting the right value. so give it another chance at
501 * offset 0x20 (FIFO_W).
502 */
503 rc = i2c_nuvoton_read_buf(client, TPM_DATA_FIFO_W, 4,
504 (u8 *) (&temp));
505 if (rc < 0)
506 return rc;
507
508 /* check WPCT301 values - ignore RID */
509 if (memcmp(&temp, vid_did_rid_value,
510 sizeof(vid_did_rid_value)))
511 return -ENODEV;
512 }
513
514 *res = temp;
515 return 0;
516}
517
518static int i2c_nuvoton_probe(struct i2c_client *client,
519 const struct i2c_device_id *id)
520{
521 int rc;
522 struct tpm_chip *chip;
523 struct device *dev = &client->dev;
524 u32 vid = 0;
525
526 rc = get_vid(client, &vid);
527 if (rc)
528 return rc;
529
530 dev_info(dev, "VID: %04X DID: %02X RID: %02X\n", (u16) vid,
531 (u8) (vid >> 16), (u8) (vid >> 24));
532
Jarkko Sakkinenafb5abc2014-12-12 11:46:34 -0800533 chip = tpmm_chip_alloc(dev, &tpm_i2c);
534 if (IS_ERR(chip))
535 return PTR_ERR(chip);
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600536
537 chip->vendor.priv = devm_kzalloc(dev, sizeof(struct priv_data),
538 GFP_KERNEL);
Jarkko Sakkinenafb5abc2014-12-12 11:46:34 -0800539 if (!chip->vendor.priv)
540 return -ENOMEM;
Kiran Padwalbb95cd32014-09-19 12:44:39 +0530541
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600542 init_waitqueue_head(&chip->vendor.read_queue);
543 init_waitqueue_head(&chip->vendor.int_queue);
544
545 /* Default timeouts */
546 chip->vendor.timeout_a = msecs_to_jiffies(TPM_I2C_SHORT_TIMEOUT);
547 chip->vendor.timeout_b = msecs_to_jiffies(TPM_I2C_LONG_TIMEOUT);
548 chip->vendor.timeout_c = msecs_to_jiffies(TPM_I2C_SHORT_TIMEOUT);
549 chip->vendor.timeout_d = msecs_to_jiffies(TPM_I2C_SHORT_TIMEOUT);
550
551 /*
552 * I2C intfcaps (interrupt capabilitieis) in the chip are hard coded to:
553 * TPM_INTF_INT_LEVEL_LOW | TPM_INTF_DATA_AVAIL_INT
554 * The IRQ should be set in the i2c_board_info (which is done
555 * automatically in of_i2c_register_devices, for device tree users */
556 chip->vendor.irq = client->irq;
557
558 if (chip->vendor.irq) {
559 dev_dbg(dev, "%s() chip-vendor.irq\n", __func__);
560 rc = devm_request_irq(dev, chip->vendor.irq,
561 i2c_nuvoton_int_handler,
562 IRQF_TRIGGER_LOW,
Jarkko Sakkinen313d21e2014-12-12 11:46:37 -0800563 chip->devname,
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600564 chip);
565 if (rc) {
566 dev_err(dev, "%s() Unable to request irq: %d for use\n",
567 __func__, chip->vendor.irq);
568 chip->vendor.irq = 0;
569 } else {
570 /* Clear any pending interrupt */
571 i2c_nuvoton_ready(chip);
572 /* - wait for TPM_STS==0xA0 (stsValid, commandReady) */
573 rc = i2c_nuvoton_wait_for_stat(chip,
574 TPM_STS_COMMAND_READY,
575 TPM_STS_COMMAND_READY,
576 chip->vendor.timeout_b,
577 NULL);
578 if (rc == 0) {
579 /*
580 * TIS is in ready state
581 * write dummy byte to enter reception state
582 * TPM_DATA_FIFO_W <- rc (0)
583 */
584 rc = i2c_nuvoton_write_buf(client,
585 TPM_DATA_FIFO_W,
586 1, (u8 *) (&rc));
587 if (rc < 0)
Jarkko Sakkinenafb5abc2014-12-12 11:46:34 -0800588 return rc;
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600589 /* TPM_STS <- 0x40 (commandReady) */
590 i2c_nuvoton_ready(chip);
591 } else {
592 /*
593 * timeout_b reached - command was
594 * aborted. TIS should now be in idle state -
595 * only TPM_STS_VALID should be set
596 */
597 if (i2c_nuvoton_read_status(chip) !=
Jarkko Sakkinenafb5abc2014-12-12 11:46:34 -0800598 TPM_STS_VALID)
599 return -EIO;
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600600 }
601 }
602 }
603
Jarkko Sakkinenafb5abc2014-12-12 11:46:34 -0800604 if (tpm_get_timeouts(chip))
605 return -ENODEV;
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600606
Jarkko Sakkinenafb5abc2014-12-12 11:46:34 -0800607 if (tpm_do_selftest(chip))
608 return -ENODEV;
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600609
Jarkko Sakkinenafb5abc2014-12-12 11:46:34 -0800610 return tpm_chip_register(chip);
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600611}
612
613static int i2c_nuvoton_remove(struct i2c_client *client)
614{
615 struct device *dev = &(client->dev);
616 struct tpm_chip *chip = dev_get_drvdata(dev);
Jarkko Sakkinenafb5abc2014-12-12 11:46:34 -0800617 tpm_chip_unregister(chip);
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600618 return 0;
619}
620
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600621static const struct i2c_device_id i2c_nuvoton_id[] = {
622 {I2C_DRIVER_NAME, 0},
623 {}
624};
625MODULE_DEVICE_TABLE(i2c, i2c_nuvoton_id);
626
627#ifdef CONFIG_OF
628static const struct of_device_id i2c_nuvoton_of_match[] = {
629 {.compatible = "nuvoton,npct501"},
630 {.compatible = "winbond,wpct301"},
631 {},
632};
633MODULE_DEVICE_TABLE(of, i2c_nuvoton_of_match);
634#endif
635
636static SIMPLE_DEV_PM_OPS(i2c_nuvoton_pm_ops, tpm_pm_suspend, tpm_pm_resume);
637
638static struct i2c_driver i2c_nuvoton_driver = {
639 .id_table = i2c_nuvoton_id,
640 .probe = i2c_nuvoton_probe,
641 .remove = i2c_nuvoton_remove,
642 .driver = {
643 .name = I2C_DRIVER_NAME,
Jason Gunthorpe4c336e42013-10-06 12:43:13 -0600644 .pm = &i2c_nuvoton_pm_ops,
645 .of_match_table = of_match_ptr(i2c_nuvoton_of_match),
646 },
647};
648
649module_i2c_driver(i2c_nuvoton_driver);
650
651MODULE_AUTHOR("Dan Morav (dan.morav@nuvoton.com)");
652MODULE_DESCRIPTION("Nuvoton TPM I2C Driver");
653MODULE_LICENSE("GPL");