summaryrefslogtreecommitdiff
path: root/drivers/watchdog/ziirave_wdt.c
blob: b3e255b40209a194380daa5587ad24429d6b2265 (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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2015 Zodiac Inflight Innovations
 *
 * Author: Martyn Welch <martyn.welch@collabora.co.uk>
 *
 * Based on twl4030_wdt.c by Timo Kokkonen <timo.t.kokkonen at nokia.com>:
 *
 * Copyright (C) Nokia Corporation
 */

#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/ihex.h>
#include <linux/firmware.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/types.h>
#include <linux/version.h>
#include <linux/watchdog.h>

#define ZIIRAVE_TIMEOUT_MIN	3
#define ZIIRAVE_TIMEOUT_MAX	255

#define ZIIRAVE_PING_VALUE	0x0

#define ZIIRAVE_STATE_INITIAL	0x0
#define ZIIRAVE_STATE_OFF	0x1
#define ZIIRAVE_STATE_ON	0x2

#define ZIIRAVE_FW_NAME		"ziirave_wdt.fw"

static char *ziirave_reasons[] = {"power cycle", "hw watchdog", NULL, NULL,
				  "host request", NULL, "illegal configuration",
				  "illegal instruction", "illegal trap",
				  "unknown"};

#define ZIIRAVE_WDT_FIRM_VER_MAJOR	0x1
#define ZIIRAVE_WDT_BOOT_VER_MAJOR	0x3
#define ZIIRAVE_WDT_RESET_REASON	0x5
#define ZIIRAVE_WDT_STATE		0x6
#define ZIIRAVE_WDT_TIMEOUT		0x7
#define ZIIRAVE_WDT_TIME_LEFT		0x8
#define ZIIRAVE_WDT_PING		0x9
#define ZIIRAVE_WDT_RESET_DURATION	0xa

#define ZIIRAVE_FIRM_PKT_TOTAL_SIZE	20
#define ZIIRAVE_FIRM_PKT_DATA_SIZE	16
#define ZIIRAVE_FIRM_FLASH_MEMORY_START	0x1600
#define ZIIRAVE_FIRM_FLASH_MEMORY_END	0x2bbf

/* Received and ready for next Download packet. */
#define ZIIRAVE_FIRM_DOWNLOAD_ACK	1
/* Currently writing to flash. Retry Download status in a moment! */
#define ZIIRAVE_FIRM_DOWNLOAD_BUSY	2

/* Wait for ACK timeout in ms */
#define ZIIRAVE_FIRM_WAIT_FOR_ACK_TIMEOUT	50

/* Firmware commands */
#define ZIIRAVE_CMD_DOWNLOAD_START		0x10
#define ZIIRAVE_CMD_DOWNLOAD_END		0x11
#define ZIIRAVE_CMD_DOWNLOAD_SET_READ_ADDR	0x12
#define ZIIRAVE_CMD_DOWNLOAD_READ_BYTE		0x13
#define ZIIRAVE_CMD_RESET_PROCESSOR		0x0b
#define ZIIRAVE_CMD_JUMP_TO_BOOTLOADER		0x0c
#define ZIIRAVE_CMD_DOWNLOAD_PACKET		0x0e

struct ziirave_wdt_rev {
	unsigned char major;
	unsigned char minor;
};

struct ziirave_wdt_data {
	struct mutex sysfs_mutex;
	struct watchdog_device wdd;
	struct ziirave_wdt_rev bootloader_rev;
	struct ziirave_wdt_rev firmware_rev;
	int reset_reason;
};

static int wdt_timeout;
module_param(wdt_timeout, int, 0);
MODULE_PARM_DESC(wdt_timeout, "Watchdog timeout in seconds");

static int reset_duration;
module_param(reset_duration, int, 0);
MODULE_PARM_DESC(reset_duration,
		 "Watchdog reset pulse duration in milliseconds");

static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started default="
		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

static int ziirave_wdt_revision(struct i2c_client *client,
				struct ziirave_wdt_rev *rev, u8 command)
{
	int ret;

	ret = i2c_smbus_read_byte_data(client, command);
	if (ret < 0)
		return ret;

	rev->major = ret;

	ret = i2c_smbus_read_byte_data(client, command + 1);
	if (ret < 0)
		return ret;

	rev->minor = ret;

	return 0;
}

static int ziirave_wdt_set_state(struct watchdog_device *wdd, int state)
{
	struct i2c_client *client = to_i2c_client(wdd->parent);

	return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_STATE, state);
}

static int ziirave_wdt_start(struct watchdog_device *wdd)
{
	return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_ON);
}

static int ziirave_wdt_stop(struct watchdog_device *wdd)
{
	return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_OFF);
}

static int ziirave_wdt_ping(struct watchdog_device *wdd)
{
	struct i2c_client *client = to_i2c_client(wdd->parent);

	return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_PING,
					 ZIIRAVE_PING_VALUE);
}

static int ziirave_wdt_set_timeout(struct watchdog_device *wdd,
				   unsigned int timeout)
{
	struct i2c_client *client = to_i2c_client(wdd->parent);
	int ret;

	ret = i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_TIMEOUT, timeout);
	if (!ret)
		wdd->timeout = timeout;

	return ret;
}

static unsigned int ziirave_wdt_get_timeleft(struct watchdog_device *wdd)
{
	struct i2c_client *client = to_i2c_client(wdd->parent);
	int ret;

	ret = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIME_LEFT);
	if (ret < 0)
		ret = 0;

	return ret;
}

static int ziirave_firm_wait_for_ack(struct watchdog_device *wdd)
{
	struct i2c_client *client = to_i2c_client(wdd->parent);
	int ret;
	unsigned long timeout;

	timeout = jiffies + msecs_to_jiffies(ZIIRAVE_FIRM_WAIT_FOR_ACK_TIMEOUT);
	do {
		if (time_after(jiffies, timeout))
			return -ETIMEDOUT;

		usleep_range(5000, 10000);

		ret = i2c_smbus_read_byte(client);
		if (ret < 0) {
			dev_err(&client->dev, "Failed to read byte\n");
			return ret;
		}
	} while (ret == ZIIRAVE_FIRM_DOWNLOAD_BUSY);

	return ret == ZIIRAVE_FIRM_DOWNLOAD_ACK ? 0 : -EIO;
}

static int ziirave_firm_set_read_addr(struct watchdog_device *wdd, u16 addr)
{
	struct i2c_client *client = to_i2c_client(wdd->parent);
	u8 address[2];

	address[0] = addr & 0xff;
	address[1] = (addr >> 8) & 0xff;

	return i2c_smbus_write_block_data(client,
					  ZIIRAVE_CMD_DOWNLOAD_SET_READ_ADDR,
					  ARRAY_SIZE(address), address);
}

static int ziirave_firm_write_block_data(struct watchdog_device *wdd,
					 u8 command, u8 length, const u8 *data,
					 bool wait_for_ack)
{
	struct i2c_client *client = to_i2c_client(wdd->parent);
	int ret;

	ret = i2c_smbus_write_block_data(client, command, length, data);
	if (ret) {
		dev_err(&client->dev,
			"Failed to send command 0x%02x: %d\n", command, ret);
		return ret;
	}

	if (wait_for_ack)
		ret = ziirave_firm_wait_for_ack(wdd);

	return ret;
}

static int ziirave_firm_write_byte(struct watchdog_device *wdd, u8 command,
				   u8 byte, bool wait_for_ack)
{
	return ziirave_firm_write_block_data(wdd, command, 1, &byte,
					     wait_for_ack);
}

/*
 * ziirave_firm_write_pkt() - Build and write a firmware packet
 *
 * A packet to send to the firmware is composed by following bytes:
 *     Length | Addr0 | Addr1 | Data0 .. Data15 | Checksum |
 * Where,
 *     Length: A data byte containing the length of the data.
 *     Addr0: Low byte of the address.
 *     Addr1: High byte of the address.
 *     Data0 .. Data15: Array of 16 bytes of data.
 *     Checksum: Checksum byte to verify data integrity.
 */
static int ziirave_firm_write_pkt(struct watchdog_device *wdd,
				  const struct ihex_binrec *rec)
{
	struct i2c_client *client = to_i2c_client(wdd->parent);
	u8 i, checksum = 0, packet[ZIIRAVE_FIRM_PKT_TOTAL_SIZE];
	int ret;
	u16 addr;

	memset(packet, 0, ARRAY_SIZE(packet));

	/* Packet length */
	packet[0] = (u8)be16_to_cpu(rec->len);
	/* Packet address */
	addr = (be32_to_cpu(rec->addr) & 0xffff) >> 1;
	packet[1] = addr & 0xff;
	packet[2] = (addr & 0xff00) >> 8;

	/* Packet data */
	if (be16_to_cpu(rec->len) > ZIIRAVE_FIRM_PKT_DATA_SIZE)
		return -EMSGSIZE;
	memcpy(packet + 3, rec->data, be16_to_cpu(rec->len));

	/* Packet checksum */
	for (i = 0; i < ZIIRAVE_FIRM_PKT_TOTAL_SIZE - 1; i++)
		checksum += packet[i];
	packet[ZIIRAVE_FIRM_PKT_TOTAL_SIZE - 1] = checksum;

	ret = ziirave_firm_write_block_data(wdd, ZIIRAVE_CMD_DOWNLOAD_PACKET,
					    ARRAY_SIZE(packet), packet, true);
	if (ret)
		dev_err(&client->dev,
		      "Failed to write firmware packet at address 0x%04x: %d\n",
		      addr, ret);

	return ret;
}

static int ziirave_firm_verify(struct watchdog_device *wdd,
			       const struct firmware *fw)
{
	struct i2c_client *client = to_i2c_client(wdd->parent);
	const struct ihex_binrec *rec;
	int i, ret;
	u8 data[ZIIRAVE_FIRM_PKT_DATA_SIZE];
	u16 addr;

	for (rec = (void *)fw->data; rec; rec = ihex_next_binrec(rec)) {
		/* Zero length marks end of records */
		if (!be16_to_cpu(rec->len))
			break;

		addr = (be32_to_cpu(rec->addr) & 0xffff) >> 1;
		if (addr < ZIIRAVE_FIRM_FLASH_MEMORY_START ||
		    addr > ZIIRAVE_FIRM_FLASH_MEMORY_END)
			continue;

		ret = ziirave_firm_set_read_addr(wdd, addr);
		if (ret) {
			dev_err(&client->dev,
				"Failed to send SET_READ_ADDR command: %d\n",
				ret);
			return ret;
		}

		for (i = 0; i < ARRAY_SIZE(data); i++) {
			ret = i2c_smbus_read_byte_data(client,
						ZIIRAVE_CMD_DOWNLOAD_READ_BYTE);
			if (ret < 0) {
				dev_err(&client->dev,
					"Failed to READ DATA: %d\n", ret);
				return ret;
			}
			data[i] = ret;
		}

		if (memcmp(data, rec->data, be16_to_cpu(rec->len))) {
			dev_err(&client->dev,
				"Firmware mismatch at address 0x%04x\n", addr);
			return -EINVAL;
		}
	}

	return 0;
}

static int ziirave_firm_upload(struct watchdog_device *wdd,
			       const struct firmware *fw)
{
	struct i2c_client *client = to_i2c_client(wdd->parent);
	int ret, words_till_page_break;
	const struct ihex_binrec *rec;
	struct ihex_binrec *rec_new;

	ret = ziirave_firm_write_byte(wdd, ZIIRAVE_CMD_JUMP_TO_BOOTLOADER, 1,
				      false);
	if (ret) {
		dev_err(&client->dev, "Failed to jump to bootloader\n");
		return ret;
	}

	msleep(500);

	ret = ziirave_firm_write_byte(wdd, ZIIRAVE_CMD_DOWNLOAD_START, 1, true);
	if (ret) {
		dev_err(&client->dev, "Failed to start download\n");
		return ret;
	}

	msleep(500);

	for (rec = (void *)fw->data; rec; rec = ihex_next_binrec(rec)) {
		/* Zero length marks end of records */
		if (!be16_to_cpu(rec->len))
			break;

		/* Check max data size */
		if (be16_to_cpu(rec->len) > ZIIRAVE_FIRM_PKT_DATA_SIZE) {
			dev_err(&client->dev, "Firmware packet too long (%d)\n",
				be16_to_cpu(rec->len));
			return -EMSGSIZE;
		}

		/* Calculate words till page break */
		words_till_page_break = (64 - ((be32_to_cpu(rec->addr) >> 1) &
					 0x3f));
		if ((be16_to_cpu(rec->len) >> 1) > words_till_page_break) {
			/*
			 * Data in passes page boundary, so we need to split in
			 * two blocks of data. Create a packet with the first
			 * block of data.
			 */
			rec_new = kzalloc(sizeof(struct ihex_binrec) +
					  (words_till_page_break << 1),
					  GFP_KERNEL);
			if (!rec_new)
				return -ENOMEM;

			rec_new->len = cpu_to_be16(words_till_page_break << 1);
			rec_new->addr = rec->addr;
			memcpy(rec_new->data, rec->data,
			       be16_to_cpu(rec_new->len));

			ret = ziirave_firm_write_pkt(wdd, rec_new);
			kfree(rec_new);
			if (ret)
				return ret;

			/* Create a packet with the second block of data */
			rec_new = kzalloc(sizeof(struct ihex_binrec) +
					  be16_to_cpu(rec->len) -
					  (words_till_page_break << 1),
					  GFP_KERNEL);
			if (!rec_new)
				return -ENOMEM;

			/* Remaining bytes */
			rec_new->len = rec->len -
				       cpu_to_be16(words_till_page_break << 1);

			rec_new->addr = cpu_to_be32(be32_to_cpu(rec->addr) +
					(words_till_page_break << 1));

			memcpy(rec_new->data,
			       rec->data + (words_till_page_break << 1),
			       be16_to_cpu(rec_new->len));

			ret = ziirave_firm_write_pkt(wdd, rec_new);
			kfree(rec_new);
			if (ret)
				return ret;
		} else {
			ret = ziirave_firm_write_pkt(wdd, rec);
			if (ret)
				return ret;
		}
	}

	/* For end of download, the length field will be set to 0 */
	rec_new = kzalloc(sizeof(struct ihex_binrec) + 1, GFP_KERNEL);
	if (!rec_new)
		return -ENOMEM;

	ret = ziirave_firm_write_pkt(wdd, rec_new);
	kfree(rec_new);
	if (ret) {
		dev_err(&client->dev, "Failed to send EMPTY packet: %d\n", ret);
		return ret;
	}

	/* This sleep seems to be required */
	msleep(20);

	/* Start firmware verification */
	ret = ziirave_firm_verify(wdd, fw);
	if (ret) {
		dev_err(&client->dev,
			"Failed to verify firmware: %d\n", ret);
		return ret;
	}

	/* End download operation */
	ret = ziirave_firm_write_byte(wdd, ZIIRAVE_CMD_DOWNLOAD_END, 1, false);
	if (ret) {
		dev_err(&client->dev,
			"Failed to end firmware download: %d\n", ret);
		return ret;
	}

	/* Reset the processor */
	ret = ziirave_firm_write_byte(wdd, ZIIRAVE_CMD_RESET_PROCESSOR, 1,
				      false);
	if (ret) {
		dev_err(&client->dev,
			"Failed to reset the watchdog: %d\n", ret);
		return ret;
	}

	msleep(500);

	return 0;
}

static const struct watchdog_info ziirave_wdt_info = {
	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
	.identity = "Zodiac RAVE Watchdog",
};

static const struct watchdog_ops ziirave_wdt_ops = {
	.owner		= THIS_MODULE,
	.start		= ziirave_wdt_start,
	.stop		= ziirave_wdt_stop,
	.ping		= ziirave_wdt_ping,
	.set_timeout	= ziirave_wdt_set_timeout,
	.get_timeleft	= ziirave_wdt_get_timeleft,
};

static ssize_t ziirave_wdt_sysfs_show_firm(struct device *dev,
					   struct device_attribute *attr,
					   char *buf)
{
	struct i2c_client *client = to_i2c_client(dev->parent);
	struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
	int ret;

	ret = mutex_lock_interruptible(&w_priv->sysfs_mutex);
	if (ret)
		return ret;

	ret = sprintf(buf, "02.%02u.%02u", w_priv->firmware_rev.major,
		      w_priv->firmware_rev.minor);

	mutex_unlock(&w_priv->sysfs_mutex);

	return ret;
}

static DEVICE_ATTR(firmware_version, S_IRUGO, ziirave_wdt_sysfs_show_firm,
		   NULL);

static ssize_t ziirave_wdt_sysfs_show_boot(struct device *dev,
					   struct device_attribute *attr,
					   char *buf)
{
	struct i2c_client *client = to_i2c_client(dev->parent);
	struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
	int ret;

	ret = mutex_lock_interruptible(&w_priv->sysfs_mutex);
	if (ret)
		return ret;

	ret = sprintf(buf, "01.%02u.%02u", w_priv->bootloader_rev.major,
		      w_priv->bootloader_rev.minor);

	mutex_unlock(&w_priv->sysfs_mutex);

	return ret;
}

static DEVICE_ATTR(bootloader_version, S_IRUGO, ziirave_wdt_sysfs_show_boot,
		   NULL);

static ssize_t ziirave_wdt_sysfs_show_reason(struct device *dev,
					     struct device_attribute *attr,
					     char *buf)
{
	struct i2c_client *client = to_i2c_client(dev->parent);
	struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
	int ret;

	ret = mutex_lock_interruptible(&w_priv->sysfs_mutex);
	if (ret)
		return ret;

	ret = sprintf(buf, "%s", ziirave_reasons[w_priv->reset_reason]);

	mutex_unlock(&w_priv->sysfs_mutex);

	return ret;
}

static DEVICE_ATTR(reset_reason, S_IRUGO, ziirave_wdt_sysfs_show_reason,
		   NULL);

static ssize_t ziirave_wdt_sysfs_store_firm(struct device *dev,
					    struct device_attribute *attr,
					    const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev->parent);
	struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
	const struct firmware *fw;
	int err;

	err = request_ihex_firmware(&fw, ZIIRAVE_FW_NAME, dev);
	if (err) {
		dev_err(&client->dev, "Failed to request ihex firmware\n");
		return err;
	}

	err = mutex_lock_interruptible(&w_priv->sysfs_mutex);
	if (err)
		goto release_firmware;

	err = ziirave_firm_upload(&w_priv->wdd, fw);
	if (err) {
		dev_err(&client->dev, "The firmware update failed: %d\n", err);
		goto unlock_mutex;
	}

	/* Update firmware version */
	err = ziirave_wdt_revision(client, &w_priv->firmware_rev,
				   ZIIRAVE_WDT_FIRM_VER_MAJOR);
	if (err) {
		dev_err(&client->dev, "Failed to read firmware version: %d\n",
			err);
		goto unlock_mutex;
	}

	dev_info(&client->dev, "Firmware updated to version 02.%02u.%02u\n",
		 w_priv->firmware_rev.major, w_priv->firmware_rev.minor);

	/* Restore the watchdog timeout */
	err = ziirave_wdt_set_timeout(&w_priv->wdd, w_priv->wdd.timeout);
	if (err)
		dev_err(&client->dev, "Failed to set timeout: %d\n", err);

unlock_mutex:
	mutex_unlock(&w_priv->sysfs_mutex);

release_firmware:
	release_firmware(fw);

	return err ? err : count;
}

static DEVICE_ATTR(update_firmware, S_IWUSR, NULL,
		   ziirave_wdt_sysfs_store_firm);

static struct attribute *ziirave_wdt_attrs[] = {
	&dev_attr_firmware_version.attr,
	&dev_attr_bootloader_version.attr,
	&dev_attr_reset_reason.attr,
	&dev_attr_update_firmware.attr,
	NULL
};
ATTRIBUTE_GROUPS(ziirave_wdt);

static int ziirave_wdt_init_duration(struct i2c_client *client)
{
	int ret;

	if (!reset_duration) {
		/* See if the reset pulse duration is provided in an of_node */
		if (!client->dev.of_node)
			ret = -ENODEV;
		else
			ret = of_property_read_u32(client->dev.of_node,
						   "reset-duration-ms",
						   &reset_duration);
		if (ret) {
			dev_info(&client->dev,
				 "Unable to set reset pulse duration, using default\n");
			return 0;
		}
	}

	if (reset_duration < 1 || reset_duration > 255)
		return -EINVAL;

	dev_info(&client->dev, "Setting reset duration to %dms",
		 reset_duration);

	return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_RESET_DURATION,
					 reset_duration);
}

static int ziirave_wdt_probe(struct i2c_client *client,
			     const struct i2c_device_id *id)
{
	int ret;
	struct ziirave_wdt_data *w_priv;
	int val;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
		return -ENODEV;

	w_priv = devm_kzalloc(&client->dev, sizeof(*w_priv), GFP_KERNEL);
	if (!w_priv)
		return -ENOMEM;

	mutex_init(&w_priv->sysfs_mutex);

	w_priv->wdd.info = &ziirave_wdt_info;
	w_priv->wdd.ops = &ziirave_wdt_ops;
	w_priv->wdd.min_timeout = ZIIRAVE_TIMEOUT_MIN;
	w_priv->wdd.max_timeout = ZIIRAVE_TIMEOUT_MAX;
	w_priv->wdd.parent = &client->dev;
	w_priv->wdd.groups = ziirave_wdt_groups;

	watchdog_init_timeout(&w_priv->wdd, wdt_timeout, &client->dev);

	/*
	 * The default value set in the watchdog should be perfectly valid, so
	 * pass that in if we haven't provided one via the module parameter or
	 * of property.
	 */
	if (w_priv->wdd.timeout == 0) {
		val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIMEOUT);
		if (val < 0) {
			dev_err(&client->dev, "Failed to read timeout\n");
			return val;
		}

		if (val < ZIIRAVE_TIMEOUT_MIN)
			return -ENODEV;

		w_priv->wdd.timeout = val;
	} else {
		ret = ziirave_wdt_set_timeout(&w_priv->wdd,
					      w_priv->wdd.timeout);
		if (ret) {
			dev_err(&client->dev, "Failed to set timeout\n");
			return ret;
		}

		dev_info(&client->dev, "Timeout set to %ds\n",
			 w_priv->wdd.timeout);
	}

	watchdog_set_nowayout(&w_priv->wdd, nowayout);

	i2c_set_clientdata(client, w_priv);

	/* If in unconfigured state, set to stopped */
	val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_STATE);
	if (val < 0) {
		dev_err(&client->dev, "Failed to read state\n");
		return val;
	}

	if (val == ZIIRAVE_STATE_INITIAL)
		ziirave_wdt_stop(&w_priv->wdd);

	ret = ziirave_wdt_init_duration(client);
	if (ret) {
		dev_err(&client->dev, "Failed to init duration\n");
		return ret;
	}

	ret = ziirave_wdt_revision(client, &w_priv->firmware_rev,
				   ZIIRAVE_WDT_FIRM_VER_MAJOR);
	if (ret) {
		dev_err(&client->dev, "Failed to read firmware version\n");
		return ret;
	}

	ret = ziirave_wdt_revision(client, &w_priv->bootloader_rev,
				   ZIIRAVE_WDT_BOOT_VER_MAJOR);
	if (ret) {
		dev_err(&client->dev, "Failed to read bootloader version\n");
		return ret;
	}

	w_priv->reset_reason = i2c_smbus_read_byte_data(client,
						ZIIRAVE_WDT_RESET_REASON);
	if (w_priv->reset_reason < 0) {
		dev_err(&client->dev, "Failed to read reset reason\n");
		return w_priv->reset_reason;
	}

	if (w_priv->reset_reason >= ARRAY_SIZE(ziirave_reasons) ||
	    !ziirave_reasons[w_priv->reset_reason]) {
		dev_err(&client->dev, "Invalid reset reason\n");
		return -ENODEV;
	}

	ret = watchdog_register_device(&w_priv->wdd);

	return ret;
}

static int ziirave_wdt_remove(struct i2c_client *client)
{
	struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);

	watchdog_unregister_device(&w_priv->wdd);

	return 0;
}

static const struct i2c_device_id ziirave_wdt_id[] = {
	{ "rave-wdt", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, ziirave_wdt_id);

static const struct of_device_id zrv_wdt_of_match[] = {
	{ .compatible = "zii,rave-wdt", },
	{ },
};
MODULE_DEVICE_TABLE(of, zrv_wdt_of_match);

static struct i2c_driver ziirave_wdt_driver = {
	.driver = {
		.name = "ziirave_wdt",
		.of_match_table = zrv_wdt_of_match,
	},
	.probe = ziirave_wdt_probe,
	.remove = ziirave_wdt_remove,
	.id_table = ziirave_wdt_id,
};

module_i2c_driver(ziirave_wdt_driver);

MODULE_AUTHOR("Martyn Welch <martyn.welch@collabora.co.uk");
MODULE_DESCRIPTION("Zodiac Aerospace RAVE Switch Watchdog Processor Driver");
MODULE_LICENSE("GPL");