drivers/watchdog/ziirave_wdt.c

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