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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2015 Zodiac Inflight Innovations
4 *
5 * Author: Martyn Welch <martyn.welch@collabora.co.uk>
6 *
7 * Based on twl4030_wdt.c by Timo Kokkonen <timo.t.kokkonen at nokia.com>:
8 *
9 * Copyright (C) Nokia Corporation
10 */
11
12#include <linux/delay.h>
13#include <linux/i2c.h>
14#include <linux/ihex.h>
15#include <linux/firmware.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/slab.h>
19#include <linux/sysfs.h>
20#include <linux/types.h>
21#include <linux/watchdog.h>
22
23#include <asm/unaligned.h>
24
25#define ZIIRAVE_TIMEOUT_MIN 3
26#define ZIIRAVE_TIMEOUT_MAX 255
27#define ZIIRAVE_TIMEOUT_DEFAULT 30
28
29#define ZIIRAVE_PING_VALUE 0x0
30
31#define ZIIRAVE_STATE_INITIAL 0x0
32#define ZIIRAVE_STATE_OFF 0x1
33#define ZIIRAVE_STATE_ON 0x2
34
35#define ZIIRAVE_FW_NAME "ziirave_wdt.fw"
36
37static char *ziirave_reasons[] = {"power cycle", "hw watchdog", NULL, NULL,
38 "host request", NULL, "illegal configuration",
39 "illegal instruction", "illegal trap",
40 "unknown"};
41
42#define ZIIRAVE_WDT_FIRM_VER_MAJOR 0x1
43#define ZIIRAVE_WDT_BOOT_VER_MAJOR 0x3
44#define ZIIRAVE_WDT_RESET_REASON 0x5
45#define ZIIRAVE_WDT_STATE 0x6
46#define ZIIRAVE_WDT_TIMEOUT 0x7
47#define ZIIRAVE_WDT_TIME_LEFT 0x8
48#define ZIIRAVE_WDT_PING 0x9
49#define ZIIRAVE_WDT_RESET_DURATION 0xa
50
51#define ZIIRAVE_FIRM_PKT_TOTAL_SIZE 20
52#define ZIIRAVE_FIRM_PKT_DATA_SIZE 16
53#define ZIIRAVE_FIRM_FLASH_MEMORY_START (2 * 0x1600)
54#define ZIIRAVE_FIRM_FLASH_MEMORY_END (2 * 0x2bbf)
55#define ZIIRAVE_FIRM_PAGE_SIZE 128
56
57/* Received and ready for next Download packet. */
58#define ZIIRAVE_FIRM_DOWNLOAD_ACK 1
59
60/* Firmware commands */
61#define ZIIRAVE_CMD_DOWNLOAD_START 0x10
62#define ZIIRAVE_CMD_DOWNLOAD_END 0x11
63#define ZIIRAVE_CMD_DOWNLOAD_SET_READ_ADDR 0x12
64#define ZIIRAVE_CMD_DOWNLOAD_READ_BYTE 0x13
65#define ZIIRAVE_CMD_RESET_PROCESSOR 0x0b
66#define ZIIRAVE_CMD_JUMP_TO_BOOTLOADER 0x0c
67#define ZIIRAVE_CMD_DOWNLOAD_PACKET 0x0e
68
69#define ZIIRAVE_CMD_JUMP_TO_BOOTLOADER_MAGIC 1
70#define ZIIRAVE_CMD_RESET_PROCESSOR_MAGIC 1
71
72struct ziirave_wdt_rev {
73 unsigned char major;
74 unsigned char minor;
75};
76
77struct ziirave_wdt_data {
78 struct mutex sysfs_mutex;
79 struct watchdog_device wdd;
80 struct ziirave_wdt_rev bootloader_rev;
81 struct ziirave_wdt_rev firmware_rev;
82 int reset_reason;
83};
84
85static int wdt_timeout;
86module_param(wdt_timeout, int, 0);
87MODULE_PARM_DESC(wdt_timeout, "Watchdog timeout in seconds");
88
89static int reset_duration;
90module_param(reset_duration, int, 0);
91MODULE_PARM_DESC(reset_duration,
92 "Watchdog reset pulse duration in milliseconds");
93
94static bool nowayout = WATCHDOG_NOWAYOUT;
95module_param(nowayout, bool, 0);
96MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started default="
97 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
98
99static int ziirave_wdt_revision(struct i2c_client *client,
100 struct ziirave_wdt_rev *rev, u8 command)
101{
102 int ret;
103
104 ret = i2c_smbus_read_byte_data(client, command);
105 if (ret < 0)
106 return ret;
107
108 rev->major = ret;
109
110 ret = i2c_smbus_read_byte_data(client, command + 1);
111 if (ret < 0)
112 return ret;
113
114 rev->minor = ret;
115
116 return 0;
117}
118
119static int ziirave_wdt_set_state(struct watchdog_device *wdd, int state)
120{
121 struct i2c_client *client = to_i2c_client(wdd->parent);
122
123 return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_STATE, state);
124}
125
126static int ziirave_wdt_start(struct watchdog_device *wdd)
127{
128 return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_ON);
129}
130
131static int ziirave_wdt_stop(struct watchdog_device *wdd)
132{
133 return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_OFF);
134}
135
136static int ziirave_wdt_ping(struct watchdog_device *wdd)
137{
138 struct i2c_client *client = to_i2c_client(wdd->parent);
139
140 return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_PING,
141 ZIIRAVE_PING_VALUE);
142}
143
144static int ziirave_wdt_set_timeout(struct watchdog_device *wdd,
145 unsigned int timeout)
146{
147 struct i2c_client *client = to_i2c_client(wdd->parent);
148 int ret;
149
150 ret = i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_TIMEOUT, timeout);
151 if (!ret)
152 wdd->timeout = timeout;
153
154 return ret;
155}
156
157static unsigned int ziirave_wdt_get_timeleft(struct watchdog_device *wdd)
158{
159 struct i2c_client *client = to_i2c_client(wdd->parent);
160 int ret;
161
162 ret = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIME_LEFT);
163 if (ret < 0)
164 ret = 0;
165
166 return ret;
167}
168
169static int ziirave_firm_read_ack(struct watchdog_device *wdd)
170{
171 struct i2c_client *client = to_i2c_client(wdd->parent);
172 int ret;
173
174 ret = i2c_smbus_read_byte(client);
175 if (ret < 0) {
176 dev_err(&client->dev, "Failed to read status byte\n");
177 return ret;
178 }
179
180 return ret == ZIIRAVE_FIRM_DOWNLOAD_ACK ? 0 : -EIO;
181}
182
183static int ziirave_firm_set_read_addr(struct watchdog_device *wdd, u32 addr)
184{
185 struct i2c_client *client = to_i2c_client(wdd->parent);
186 const u16 addr16 = (u16)addr / 2;
187 u8 address[2];
188
189 put_unaligned_le16(addr16, address);
190
191 return i2c_smbus_write_block_data(client,
192 ZIIRAVE_CMD_DOWNLOAD_SET_READ_ADDR,
193 sizeof(address), address);
194}
195
196static bool ziirave_firm_addr_readonly(u32 addr)
197{
198 return addr < ZIIRAVE_FIRM_FLASH_MEMORY_START ||
199 addr > ZIIRAVE_FIRM_FLASH_MEMORY_END;
200}
201
202/*
203 * ziirave_firm_write_pkt() - Build and write a firmware packet
204 *
205 * A packet to send to the firmware is composed by following bytes:
206 * Length | Addr0 | Addr1 | Data0 .. Data15 | Checksum |
207 * Where,
208 * Length: A data byte containing the length of the data.
209 * Addr0: Low byte of the address.
210 * Addr1: High byte of the address.
211 * Data0 .. Data15: Array of 16 bytes of data.
212 * Checksum: Checksum byte to verify data integrity.
213 */
214static int __ziirave_firm_write_pkt(struct watchdog_device *wdd,
215 u32 addr, const u8 *data, u8 len)
216{
217 const u16 addr16 = (u16)addr / 2;
218 struct i2c_client *client = to_i2c_client(wdd->parent);
219 u8 i, checksum = 0, packet[ZIIRAVE_FIRM_PKT_TOTAL_SIZE];
220 int ret;
221
222 /* Check max data size */
223 if (len > ZIIRAVE_FIRM_PKT_DATA_SIZE) {
224 dev_err(&client->dev, "Firmware packet too long (%d)\n",
225 len);
226 return -EMSGSIZE;
227 }
228
229 /*
230 * Ignore packets that are targeting program memory outisde of
231 * app partition, since they will be ignored by the
232 * bootloader. At the same time, we need to make sure we'll
233 * allow zero length packet that will be sent as the last step
234 * of firmware update
235 */
236 if (len && ziirave_firm_addr_readonly(addr))
237 return 0;
238
239 /* Packet length */
240 packet[0] = len;
241 /* Packet address */
242 put_unaligned_le16(addr16, packet + 1);
243
244 memcpy(packet + 3, data, len);
245 memset(packet + 3 + len, 0, ZIIRAVE_FIRM_PKT_DATA_SIZE - len);
246
247 /* Packet checksum */
248 for (i = 0; i < len + 3; i++)
249 checksum += packet[i];
250 packet[ZIIRAVE_FIRM_PKT_TOTAL_SIZE - 1] = checksum;
251
252 ret = i2c_smbus_write_block_data(client, ZIIRAVE_CMD_DOWNLOAD_PACKET,
253 sizeof(packet), packet);
254 if (ret) {
255 dev_err(&client->dev,
256 "Failed to send DOWNLOAD_PACKET: %d\n", ret);
257 return ret;
258 }
259
260 ret = ziirave_firm_read_ack(wdd);
261 if (ret)
262 dev_err(&client->dev,
263 "Failed to write firmware packet at address 0x%04x: %d\n",
264 addr, ret);
265
266 return ret;
267}
268
269static int ziirave_firm_write_pkt(struct watchdog_device *wdd,
270 u32 addr, const u8 *data, u8 len)
271{
272 const u8 max_write_len = ZIIRAVE_FIRM_PAGE_SIZE -
273 (addr - ALIGN_DOWN(addr, ZIIRAVE_FIRM_PAGE_SIZE));
274 int ret;
275
276 if (len > max_write_len) {
277 /*
278 * If data crossed page boundary we need to split this
279 * write in two
280 */
281 ret = __ziirave_firm_write_pkt(wdd, addr, data, max_write_len);
282 if (ret)
283 return ret;
284
285 addr += max_write_len;
286 data += max_write_len;
287 len -= max_write_len;
288 }
289
290 return __ziirave_firm_write_pkt(wdd, addr, data, len);
291}
292
293static int ziirave_firm_verify(struct watchdog_device *wdd,
294 const struct firmware *fw)
295{
296 struct i2c_client *client = to_i2c_client(wdd->parent);
297 const struct ihex_binrec *rec;
298 int i, ret;
299 u8 data[ZIIRAVE_FIRM_PKT_DATA_SIZE];
300
301 for (rec = (void *)fw->data; rec; rec = ihex_next_binrec(rec)) {
302 const u16 len = be16_to_cpu(rec->len);
303 const u32 addr = be32_to_cpu(rec->addr);
304
305 if (ziirave_firm_addr_readonly(addr))
306 continue;
307
308 ret = ziirave_firm_set_read_addr(wdd, addr);
309 if (ret) {
310 dev_err(&client->dev,
311 "Failed to send SET_READ_ADDR command: %d\n",
312 ret);
313 return ret;
314 }
315
316 for (i = 0; i < len; i++) {
317 ret = i2c_smbus_read_byte_data(client,
318 ZIIRAVE_CMD_DOWNLOAD_READ_BYTE);
319 if (ret < 0) {
320 dev_err(&client->dev,
321 "Failed to READ DATA: %d\n", ret);
322 return ret;
323 }
324 data[i] = ret;
325 }
326
327 if (memcmp(data, rec->data, len)) {
328 dev_err(&client->dev,
329 "Firmware mismatch at address 0x%04x\n", addr);
330 return -EINVAL;
331 }
332 }
333
334 return 0;
335}
336
337static int ziirave_firm_upload(struct watchdog_device *wdd,
338 const struct firmware *fw)
339{
340 struct i2c_client *client = to_i2c_client(wdd->parent);
341 const struct ihex_binrec *rec;
342 int ret;
343
344 ret = i2c_smbus_write_byte_data(client,
345 ZIIRAVE_CMD_JUMP_TO_BOOTLOADER,
346 ZIIRAVE_CMD_JUMP_TO_BOOTLOADER_MAGIC);
347 if (ret) {
348 dev_err(&client->dev, "Failed to jump to bootloader\n");
349 return ret;
350 }
351
352 msleep(500);
353
354 ret = i2c_smbus_write_byte(client, ZIIRAVE_CMD_DOWNLOAD_START);
355 if (ret) {
356 dev_err(&client->dev, "Failed to start download\n");
357 return ret;
358 }
359
360 ret = ziirave_firm_read_ack(wdd);
361 if (ret) {
362 dev_err(&client->dev, "No ACK for start download\n");
363 return ret;
364 }
365
366 msleep(500);
367
368 for (rec = (void *)fw->data; rec; rec = ihex_next_binrec(rec)) {
369 ret = ziirave_firm_write_pkt(wdd, be32_to_cpu(rec->addr),
370 rec->data, be16_to_cpu(rec->len));
371 if (ret)
372 return ret;
373 }
374
375 /*
376 * Finish firmware download process by sending a zero length
377 * payload
378 */
379 ret = ziirave_firm_write_pkt(wdd, 0, NULL, 0);
380 if (ret) {
381 dev_err(&client->dev, "Failed to send EMPTY packet: %d\n", ret);
382 return ret;
383 }
384
385 /* This sleep seems to be required */
386 msleep(20);
387
388 /* Start firmware verification */
389 ret = ziirave_firm_verify(wdd, fw);
390 if (ret) {
391 dev_err(&client->dev,
392 "Failed to verify firmware: %d\n", ret);
393 return ret;
394 }
395
396 /* End download operation */
397 ret = i2c_smbus_write_byte(client, ZIIRAVE_CMD_DOWNLOAD_END);
398 if (ret) {
399 dev_err(&client->dev,
400 "Failed to end firmware download: %d\n", ret);
401 return ret;
402 }
403
404 /* Reset the processor */
405 ret = i2c_smbus_write_byte_data(client,
406 ZIIRAVE_CMD_RESET_PROCESSOR,
407 ZIIRAVE_CMD_RESET_PROCESSOR_MAGIC);
408 if (ret) {
409 dev_err(&client->dev,
410 "Failed to reset the watchdog: %d\n", ret);
411 return ret;
412 }
413
414 msleep(500);
415
416 return 0;
417}
418
419static const struct watchdog_info ziirave_wdt_info = {
420 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
421 .identity = "RAVE Switch Watchdog",
422};
423
424static const struct watchdog_ops ziirave_wdt_ops = {
425 .owner = THIS_MODULE,
426 .start = ziirave_wdt_start,
427 .stop = ziirave_wdt_stop,
428 .ping = ziirave_wdt_ping,
429 .set_timeout = ziirave_wdt_set_timeout,
430 .get_timeleft = ziirave_wdt_get_timeleft,
431};
432
433static ssize_t ziirave_wdt_sysfs_show_firm(struct device *dev,
434 struct device_attribute *attr,
435 char *buf)
436{
437 struct i2c_client *client = to_i2c_client(dev->parent);
438 struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
439 int ret;
440
441 ret = mutex_lock_interruptible(&w_priv->sysfs_mutex);
442 if (ret)
443 return ret;
444
445 ret = sysfs_emit(buf, "02.%02u.%02u\n",
446 w_priv->firmware_rev.major,
447 w_priv->firmware_rev.minor);
448
449 mutex_unlock(&w_priv->sysfs_mutex);
450
451 return ret;
452}
453
454static DEVICE_ATTR(firmware_version, S_IRUGO, ziirave_wdt_sysfs_show_firm,
455 NULL);
456
457static ssize_t ziirave_wdt_sysfs_show_boot(struct device *dev,
458 struct device_attribute *attr,
459 char *buf)
460{
461 struct i2c_client *client = to_i2c_client(dev->parent);
462 struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
463 int ret;
464
465 ret = mutex_lock_interruptible(&w_priv->sysfs_mutex);
466 if (ret)
467 return ret;
468
469 ret = sysfs_emit(buf, "01.%02u.%02u\n",
470 w_priv->bootloader_rev.major,
471 w_priv->bootloader_rev.minor);
472
473 mutex_unlock(&w_priv->sysfs_mutex);
474
475 return ret;
476}
477
478static DEVICE_ATTR(bootloader_version, S_IRUGO, ziirave_wdt_sysfs_show_boot,
479 NULL);
480
481static ssize_t ziirave_wdt_sysfs_show_reason(struct device *dev,
482 struct device_attribute *attr,
483 char *buf)
484{
485 struct i2c_client *client = to_i2c_client(dev->parent);
486 struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
487 int ret;
488
489 ret = mutex_lock_interruptible(&w_priv->sysfs_mutex);
490 if (ret)
491 return ret;
492
493 ret = sysfs_emit(buf, "%s\n", ziirave_reasons[w_priv->reset_reason]);
494
495 mutex_unlock(&w_priv->sysfs_mutex);
496
497 return ret;
498}
499
500static DEVICE_ATTR(reset_reason, S_IRUGO, ziirave_wdt_sysfs_show_reason,
501 NULL);
502
503static ssize_t ziirave_wdt_sysfs_store_firm(struct device *dev,
504 struct device_attribute *attr,
505 const char *buf, size_t count)
506{
507 struct i2c_client *client = to_i2c_client(dev->parent);
508 struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
509 const struct firmware *fw;
510 int err;
511
512 err = request_ihex_firmware(&fw, ZIIRAVE_FW_NAME, dev);
513 if (err) {
514 dev_err(&client->dev, "Failed to request ihex firmware\n");
515 return err;
516 }
517
518 err = mutex_lock_interruptible(&w_priv->sysfs_mutex);
519 if (err)
520 goto release_firmware;
521
522 err = ziirave_firm_upload(&w_priv->wdd, fw);
523 if (err) {
524 dev_err(&client->dev, "The firmware update failed: %d\n", err);
525 goto unlock_mutex;
526 }
527
528 /* Update firmware version */
529 err = ziirave_wdt_revision(client, &w_priv->firmware_rev,
530 ZIIRAVE_WDT_FIRM_VER_MAJOR);
531 if (err) {
532 dev_err(&client->dev, "Failed to read firmware version: %d\n",
533 err);
534 goto unlock_mutex;
535 }
536
537 dev_info(&client->dev,
538 "Firmware updated to version 02.%02u.%02u\n",
539 w_priv->firmware_rev.major, w_priv->firmware_rev.minor);
540
541 /* Restore the watchdog timeout */
542 err = ziirave_wdt_set_timeout(&w_priv->wdd, w_priv->wdd.timeout);
543 if (err)
544 dev_err(&client->dev, "Failed to set timeout: %d\n", err);
545
546unlock_mutex:
547 mutex_unlock(&w_priv->sysfs_mutex);
548
549release_firmware:
550 release_firmware(fw);
551
552 return err ? err : count;
553}
554
555static DEVICE_ATTR(update_firmware, S_IWUSR, NULL,
556 ziirave_wdt_sysfs_store_firm);
557
558static struct attribute *ziirave_wdt_attrs[] = {
559 &dev_attr_firmware_version.attr,
560 &dev_attr_bootloader_version.attr,
561 &dev_attr_reset_reason.attr,
562 &dev_attr_update_firmware.attr,
563 NULL
564};
565ATTRIBUTE_GROUPS(ziirave_wdt);
566
567static int ziirave_wdt_init_duration(struct i2c_client *client)
568{
569 int ret;
570
571 if (!reset_duration) {
572 /* See if the reset pulse duration is provided in an of_node */
573 if (!client->dev.of_node)
574 ret = -ENODEV;
575 else
576 ret = of_property_read_u32(client->dev.of_node,
577 "reset-duration-ms",
578 &reset_duration);
579 if (ret) {
580 dev_info(&client->dev,
581 "No reset pulse duration specified, using default\n");
582 return 0;
583 }
584 }
585
586 if (reset_duration < 1 || reset_duration > 255)
587 return -EINVAL;
588
589 dev_info(&client->dev, "Setting reset duration to %dms",
590 reset_duration);
591
592 return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_RESET_DURATION,
593 reset_duration);
594}
595
596static int ziirave_wdt_probe(struct i2c_client *client,
597 const struct i2c_device_id *id)
598{
599 int ret;
600 struct ziirave_wdt_data *w_priv;
601 int val;
602
603 if (!i2c_check_functionality(client->adapter,
604 I2C_FUNC_SMBUS_BYTE |
605 I2C_FUNC_SMBUS_BYTE_DATA |
606 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA))
607 return -ENODEV;
608
609 w_priv = devm_kzalloc(&client->dev, sizeof(*w_priv), GFP_KERNEL);
610 if (!w_priv)
611 return -ENOMEM;
612
613 mutex_init(&w_priv->sysfs_mutex);
614
615 w_priv->wdd.info = &ziirave_wdt_info;
616 w_priv->wdd.ops = &ziirave_wdt_ops;
617 w_priv->wdd.min_timeout = ZIIRAVE_TIMEOUT_MIN;
618 w_priv->wdd.max_timeout = ZIIRAVE_TIMEOUT_MAX;
619 w_priv->wdd.parent = &client->dev;
620 w_priv->wdd.groups = ziirave_wdt_groups;
621
622 watchdog_init_timeout(&w_priv->wdd, wdt_timeout, &client->dev);
623
624 /*
625 * The default value set in the watchdog should be perfectly valid, so
626 * pass that in if we haven't provided one via the module parameter or
627 * of property.
628 */
629 if (w_priv->wdd.timeout == 0) {
630 val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIMEOUT);
631 if (val < 0) {
632 dev_err(&client->dev, "Failed to read timeout\n");
633 return val;
634 }
635
636 if (val > ZIIRAVE_TIMEOUT_MAX ||
637 val < ZIIRAVE_TIMEOUT_MIN)
638 val = ZIIRAVE_TIMEOUT_DEFAULT;
639
640 w_priv->wdd.timeout = val;
641 }
642
643 ret = ziirave_wdt_set_timeout(&w_priv->wdd, w_priv->wdd.timeout);
644 if (ret) {
645 dev_err(&client->dev, "Failed to set timeout\n");
646 return ret;
647 }
648
649 dev_info(&client->dev, "Timeout set to %ds\n", w_priv->wdd.timeout);
650
651 watchdog_set_nowayout(&w_priv->wdd, nowayout);
652
653 i2c_set_clientdata(client, w_priv);
654
655 /* If in unconfigured state, set to stopped */
656 val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_STATE);
657 if (val < 0) {
658 dev_err(&client->dev, "Failed to read state\n");
659 return val;
660 }
661
662 if (val == ZIIRAVE_STATE_INITIAL)
663 ziirave_wdt_stop(&w_priv->wdd);
664
665 ret = ziirave_wdt_init_duration(client);
666 if (ret) {
667 dev_err(&client->dev, "Failed to init duration\n");
668 return ret;
669 }
670
671 ret = ziirave_wdt_revision(client, &w_priv->firmware_rev,
672 ZIIRAVE_WDT_FIRM_VER_MAJOR);
673 if (ret) {
674 dev_err(&client->dev, "Failed to read firmware version\n");
675 return ret;
676 }
677
678 dev_info(&client->dev,
679 "Firmware version: 02.%02u.%02u\n",
680 w_priv->firmware_rev.major, w_priv->firmware_rev.minor);
681
682 ret = ziirave_wdt_revision(client, &w_priv->bootloader_rev,
683 ZIIRAVE_WDT_BOOT_VER_MAJOR);
684 if (ret) {
685 dev_err(&client->dev, "Failed to read bootloader version\n");
686 return ret;
687 }
688
689 dev_info(&client->dev,
690 "Bootloader version: 01.%02u.%02u\n",
691 w_priv->bootloader_rev.major, w_priv->bootloader_rev.minor);
692
693 w_priv->reset_reason = i2c_smbus_read_byte_data(client,
694 ZIIRAVE_WDT_RESET_REASON);
695 if (w_priv->reset_reason < 0) {
696 dev_err(&client->dev, "Failed to read reset reason\n");
697 return w_priv->reset_reason;
698 }
699
700 if (w_priv->reset_reason >= ARRAY_SIZE(ziirave_reasons) ||
701 !ziirave_reasons[w_priv->reset_reason]) {
702 dev_err(&client->dev, "Invalid reset reason\n");
703 return -ENODEV;
704 }
705
706 ret = watchdog_register_device(&w_priv->wdd);
707
708 return ret;
709}
710
711static void ziirave_wdt_remove(struct i2c_client *client)
712{
713 struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
714
715 watchdog_unregister_device(&w_priv->wdd);
716}
717
718static const struct i2c_device_id ziirave_wdt_id[] = {
719 { "rave-wdt", 0 },
720 { }
721};
722MODULE_DEVICE_TABLE(i2c, ziirave_wdt_id);
723
724static const struct of_device_id zrv_wdt_of_match[] = {
725 { .compatible = "zii,rave-wdt", },
726 { },
727};
728MODULE_DEVICE_TABLE(of, zrv_wdt_of_match);
729
730static struct i2c_driver ziirave_wdt_driver = {
731 .driver = {
732 .name = "ziirave_wdt",
733 .of_match_table = zrv_wdt_of_match,
734 },
735 .probe = ziirave_wdt_probe,
736 .remove = ziirave_wdt_remove,
737 .id_table = ziirave_wdt_id,
738};
739
740module_i2c_driver(ziirave_wdt_driver);
741
742MODULE_AUTHOR("Martyn Welch <martyn.welch@collabora.co.uk");
743MODULE_DESCRIPTION("Zodiac Aerospace RAVE Switch Watchdog Processor Driver");
744MODULE_LICENSE("GPL");
1/*
2 * Copyright (C) 2015 Zodiac Inflight Innovations
3 *
4 * Author: Martyn Welch <martyn.welch@collabora.co.uk>
5 *
6 * Based on twl4030_wdt.c by Timo Kokkonen <timo.t.kokkonen at nokia.com>:
7 *
8 * Copyright (C) Nokia Corporation
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 */
20
21#include <linux/i2c.h>
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/slab.h>
25#include <linux/sysfs.h>
26#include <linux/types.h>
27#include <linux/version.h>
28#include <linux/watchdog.h>
29
30#define ZIIRAVE_TIMEOUT_MIN 3
31#define ZIIRAVE_TIMEOUT_MAX 255
32
33#define ZIIRAVE_PING_VALUE 0x0
34
35#define ZIIRAVE_STATE_INITIAL 0x0
36#define ZIIRAVE_STATE_OFF 0x1
37#define ZIIRAVE_STATE_ON 0x2
38
39static char *ziirave_reasons[] = {"power cycle", "hw watchdog", NULL, NULL,
40 "host request", NULL, "illegal configuration",
41 "illegal instruction", "illegal trap",
42 "unknown"};
43
44#define ZIIRAVE_WDT_FIRM_VER_MAJOR 0x1
45#define ZIIRAVE_WDT_BOOT_VER_MAJOR 0x3
46#define ZIIRAVE_WDT_RESET_REASON 0x5
47#define ZIIRAVE_WDT_STATE 0x6
48#define ZIIRAVE_WDT_TIMEOUT 0x7
49#define ZIIRAVE_WDT_TIME_LEFT 0x8
50#define ZIIRAVE_WDT_PING 0x9
51#define ZIIRAVE_WDT_RESET_DURATION 0xa
52
53struct ziirave_wdt_rev {
54 unsigned char major;
55 unsigned char minor;
56};
57
58struct ziirave_wdt_data {
59 struct watchdog_device wdd;
60 struct ziirave_wdt_rev bootloader_rev;
61 struct ziirave_wdt_rev firmware_rev;
62 int reset_reason;
63};
64
65static int wdt_timeout;
66module_param(wdt_timeout, int, 0);
67MODULE_PARM_DESC(wdt_timeout, "Watchdog timeout in seconds");
68
69static int reset_duration;
70module_param(reset_duration, int, 0);
71MODULE_PARM_DESC(reset_duration,
72 "Watchdog reset pulse duration in milliseconds");
73
74static bool nowayout = WATCHDOG_NOWAYOUT;
75module_param(nowayout, bool, 0);
76MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started default="
77 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
78
79static int ziirave_wdt_revision(struct i2c_client *client,
80 struct ziirave_wdt_rev *rev, u8 command)
81{
82 int ret;
83
84 ret = i2c_smbus_read_byte_data(client, command);
85 if (ret < 0)
86 return ret;
87
88 rev->major = ret;
89
90 ret = i2c_smbus_read_byte_data(client, command + 1);
91 if (ret < 0)
92 return ret;
93
94 rev->minor = ret;
95
96 return 0;
97}
98
99static int ziirave_wdt_set_state(struct watchdog_device *wdd, int state)
100{
101 struct i2c_client *client = to_i2c_client(wdd->parent);
102
103 return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_STATE, state);
104}
105
106static int ziirave_wdt_start(struct watchdog_device *wdd)
107{
108 return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_ON);
109}
110
111static int ziirave_wdt_stop(struct watchdog_device *wdd)
112{
113 return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_OFF);
114}
115
116static int ziirave_wdt_ping(struct watchdog_device *wdd)
117{
118 struct i2c_client *client = to_i2c_client(wdd->parent);
119
120 return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_PING,
121 ZIIRAVE_PING_VALUE);
122}
123
124static int ziirave_wdt_set_timeout(struct watchdog_device *wdd,
125 unsigned int timeout)
126{
127 struct i2c_client *client = to_i2c_client(wdd->parent);
128 int ret;
129
130 ret = i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_TIMEOUT, timeout);
131 if (!ret)
132 wdd->timeout = timeout;
133
134 return ret;
135}
136
137static unsigned int ziirave_wdt_get_timeleft(struct watchdog_device *wdd)
138{
139 struct i2c_client *client = to_i2c_client(wdd->parent);
140 int ret;
141
142 ret = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIME_LEFT);
143 if (ret < 0)
144 ret = 0;
145
146 return ret;
147}
148
149static const struct watchdog_info ziirave_wdt_info = {
150 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
151 .identity = "Zodiac RAVE Watchdog",
152};
153
154static const struct watchdog_ops ziirave_wdt_ops = {
155 .owner = THIS_MODULE,
156 .start = ziirave_wdt_start,
157 .stop = ziirave_wdt_stop,
158 .ping = ziirave_wdt_ping,
159 .set_timeout = ziirave_wdt_set_timeout,
160 .get_timeleft = ziirave_wdt_get_timeleft,
161};
162
163static ssize_t ziirave_wdt_sysfs_show_firm(struct device *dev,
164 struct device_attribute *attr,
165 char *buf)
166{
167 struct i2c_client *client = to_i2c_client(dev->parent);
168 struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
169
170 return sprintf(buf, "02.%02u.%02u", w_priv->firmware_rev.major,
171 w_priv->firmware_rev.minor);
172}
173
174static DEVICE_ATTR(firmware_version, S_IRUGO, ziirave_wdt_sysfs_show_firm,
175 NULL);
176
177static ssize_t ziirave_wdt_sysfs_show_boot(struct device *dev,
178 struct device_attribute *attr,
179 char *buf)
180{
181 struct i2c_client *client = to_i2c_client(dev->parent);
182 struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
183
184 return sprintf(buf, "01.%02u.%02u", w_priv->bootloader_rev.major,
185 w_priv->bootloader_rev.minor);
186}
187
188static DEVICE_ATTR(bootloader_version, S_IRUGO, ziirave_wdt_sysfs_show_boot,
189 NULL);
190
191static ssize_t ziirave_wdt_sysfs_show_reason(struct device *dev,
192 struct device_attribute *attr,
193 char *buf)
194{
195 struct i2c_client *client = to_i2c_client(dev->parent);
196 struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
197
198 return sprintf(buf, "%s", ziirave_reasons[w_priv->reset_reason]);
199}
200
201static DEVICE_ATTR(reset_reason, S_IRUGO, ziirave_wdt_sysfs_show_reason,
202 NULL);
203
204static struct attribute *ziirave_wdt_attrs[] = {
205 &dev_attr_firmware_version.attr,
206 &dev_attr_bootloader_version.attr,
207 &dev_attr_reset_reason.attr,
208 NULL
209};
210ATTRIBUTE_GROUPS(ziirave_wdt);
211
212static int ziirave_wdt_init_duration(struct i2c_client *client)
213{
214 int ret;
215
216 if (!reset_duration) {
217 /* See if the reset pulse duration is provided in an of_node */
218 if (!client->dev.of_node)
219 ret = -ENODEV;
220 else
221 ret = of_property_read_u32(client->dev.of_node,
222 "reset-duration-ms",
223 &reset_duration);
224 if (ret) {
225 dev_info(&client->dev,
226 "Unable to set reset pulse duration, using default\n");
227 return 0;
228 }
229 }
230
231 if (reset_duration < 1 || reset_duration > 255)
232 return -EINVAL;
233
234 dev_info(&client->dev, "Setting reset duration to %dms",
235 reset_duration);
236
237 return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_RESET_DURATION,
238 reset_duration);
239}
240
241static int ziirave_wdt_probe(struct i2c_client *client,
242 const struct i2c_device_id *id)
243{
244 int ret;
245 struct ziirave_wdt_data *w_priv;
246 int val;
247
248 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
249 return -ENODEV;
250
251 w_priv = devm_kzalloc(&client->dev, sizeof(*w_priv), GFP_KERNEL);
252 if (!w_priv)
253 return -ENOMEM;
254
255 w_priv->wdd.info = &ziirave_wdt_info;
256 w_priv->wdd.ops = &ziirave_wdt_ops;
257 w_priv->wdd.min_timeout = ZIIRAVE_TIMEOUT_MIN;
258 w_priv->wdd.max_timeout = ZIIRAVE_TIMEOUT_MAX;
259 w_priv->wdd.parent = &client->dev;
260 w_priv->wdd.groups = ziirave_wdt_groups;
261
262 ret = watchdog_init_timeout(&w_priv->wdd, wdt_timeout, &client->dev);
263 if (ret) {
264 dev_info(&client->dev,
265 "Unable to select timeout value, using default\n");
266 }
267
268 /*
269 * The default value set in the watchdog should be perfectly valid, so
270 * pass that in if we haven't provided one via the module parameter or
271 * of property.
272 */
273 if (w_priv->wdd.timeout == 0) {
274 val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIMEOUT);
275 if (val < 0)
276 return val;
277
278 if (val < ZIIRAVE_TIMEOUT_MIN)
279 return -ENODEV;
280
281 w_priv->wdd.timeout = val;
282 } else {
283 ret = ziirave_wdt_set_timeout(&w_priv->wdd,
284 w_priv->wdd.timeout);
285 if (ret)
286 return ret;
287
288 dev_info(&client->dev, "Timeout set to %ds.",
289 w_priv->wdd.timeout);
290 }
291
292 watchdog_set_nowayout(&w_priv->wdd, nowayout);
293
294 i2c_set_clientdata(client, w_priv);
295
296 /* If in unconfigured state, set to stopped */
297 val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_STATE);
298 if (val < 0)
299 return val;
300
301 if (val == ZIIRAVE_STATE_INITIAL)
302 ziirave_wdt_stop(&w_priv->wdd);
303
304 ret = ziirave_wdt_init_duration(client);
305 if (ret)
306 return ret;
307
308 ret = ziirave_wdt_revision(client, &w_priv->firmware_rev,
309 ZIIRAVE_WDT_FIRM_VER_MAJOR);
310 if (ret)
311 return ret;
312
313 ret = ziirave_wdt_revision(client, &w_priv->bootloader_rev,
314 ZIIRAVE_WDT_BOOT_VER_MAJOR);
315 if (ret)
316 return ret;
317
318 w_priv->reset_reason = i2c_smbus_read_byte_data(client,
319 ZIIRAVE_WDT_RESET_REASON);
320 if (w_priv->reset_reason < 0)
321 return w_priv->reset_reason;
322
323 if (w_priv->reset_reason >= ARRAY_SIZE(ziirave_reasons) ||
324 !ziirave_reasons[w_priv->reset_reason])
325 return -ENODEV;
326
327 ret = watchdog_register_device(&w_priv->wdd);
328
329 return ret;
330}
331
332static int ziirave_wdt_remove(struct i2c_client *client)
333{
334 struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
335
336 watchdog_unregister_device(&w_priv->wdd);
337
338 return 0;
339}
340
341static struct i2c_device_id ziirave_wdt_id[] = {
342 { "ziirave-wdt", 0 },
343 { }
344};
345MODULE_DEVICE_TABLE(i2c, ziirave_wdt_id);
346
347static const struct of_device_id zrv_wdt_of_match[] = {
348 { .compatible = "zii,rave-wdt", },
349 { },
350};
351MODULE_DEVICE_TABLE(of, zrv_wdt_of_match);
352
353static struct i2c_driver ziirave_wdt_driver = {
354 .driver = {
355 .name = "ziirave_wdt",
356 .of_match_table = zrv_wdt_of_match,
357 },
358 .probe = ziirave_wdt_probe,
359 .remove = ziirave_wdt_remove,
360 .id_table = ziirave_wdt_id,
361};
362
363module_i2c_driver(ziirave_wdt_driver);
364
365MODULE_AUTHOR("Martyn Welch <martyn.welch@collabora.co.uk");
366MODULE_DESCRIPTION("Zodiac Aerospace RAVE Switch Watchdog Processor Driver");
367MODULE_LICENSE("GPL");