drivers/watchdog/orion_wdt.c

   1 /*
   2  * drivers/watchdog/orion_wdt.c
   3  *
   4  * Watchdog driver for Orion/Kirkwood processors
   5  *
   6  * Author: Sylver Bruneau <sylver.bruneau@googlemail.com>
   7  *
   8  * This file is licensed under  the terms of the GNU General Public
   9  * License version 2. This program is licensed "as is" without any
  10  * warranty of any kind, whether express or implied.
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <linux/module.h>
  16 #include <linux/moduleparam.h>
  17 #include <linux/types.h>
  18 #include <linux/kernel.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/watchdog.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/io.h>
  23 #include <linux/clk.h>
  24 #include <linux/err.h>
  25 #include <linux/of.h>
  26 #include <linux/of_device.h>
  27
  28 /* RSTOUT mask register physical address for Orion5x, Kirkwood and Dove */
  29 #define ORION_RSTOUT_MASK_OFFSET        0x20108
  30
  31 /* Internal registers can be configured at any 1 MiB aligned address */
  32 #define INTERNAL_REGS_MASK              ~(SZ_1M - 1)
  33
  34 /*
  35  * Watchdog timer block registers.
  36  */
  37 #define TIMER_CTRL              0x0000
  38 #define TIMER_A370_STATUS       0x04
  39
  40 #define WDT_MAX_CYCLE_COUNT     0xffffffff
  41
  42 #define WDT_A370_RATIO_MASK(v)  ((v) << 16)
  43 #define WDT_A370_RATIO_SHIFT    5
  44 #define WDT_A370_RATIO          (1 << WDT_A370_RATIO_SHIFT)
  45
  46 #define WDT_AXP_FIXED_ENABLE_BIT BIT(10)
  47 #define WDT_A370_EXPIRED        BIT(31)
  48
  49 static bool nowayout = WATCHDOG_NOWAYOUT;
  50 static int heartbeat = -1;              /* module parameter (seconds) */
  51
  52 struct orion_watchdog;
  53
  54 struct orion_watchdog_data {
  55         int wdt_counter_offset;
  56         int wdt_enable_bit;
  57         int rstout_enable_bit;
  58         int rstout_mask_bit;
  59         int (*clock_init)(struct platform_device *,
  60                           struct orion_watchdog *);
  61         int (*enabled)(struct orion_watchdog *);
  62         int (*start)(struct watchdog_device *);
  63         int (*stop)(struct watchdog_device *);
  64 };
  65
  66 struct orion_watchdog {
  67         struct watchdog_device wdt;
  68         void __iomem *reg;
  69         void __iomem *rstout;
  70         void __iomem *rstout_mask;
  71         unsigned long clk_rate;
  72         struct clk *clk;
  73         const struct orion_watchdog_data *data;
  74 };
  75
  76 static int orion_wdt_clock_init(struct platform_device *pdev,
  77                                 struct orion_watchdog *dev)
  78 {
  79         int ret;
  80
  81         dev->clk = clk_get(&pdev->dev, NULL);
  82         if (IS_ERR(dev->clk))
  83                 return PTR_ERR(dev->clk);
  84         ret = clk_prepare_enable(dev->clk);
  85         if (ret) {
  86                 clk_put(dev->clk);
  87                 return ret;
  88         }
  89
  90         dev->clk_rate = clk_get_rate(dev->clk);
  91         return 0;
  92 }
  93
  94 static int armada370_wdt_clock_init(struct platform_device *pdev,
  95                                     struct orion_watchdog *dev)
  96 {
  97         int ret;
  98
  99         dev->clk = clk_get(&pdev->dev, NULL);
 100         if (IS_ERR(dev->clk))
 101                 return PTR_ERR(dev->clk);
 102         ret = clk_prepare_enable(dev->clk);
 103         if (ret) {
 104                 clk_put(dev->clk);
 105                 return ret;
 106         }
 107
 108         /* Setup watchdog input clock */
 109         atomic_io_modify(dev->reg + TIMER_CTRL,
 110                         WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT),
 111                         WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT));
 112
 113         dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO;
 114         return 0;
 115 }
 116
 117 static int armada375_wdt_clock_init(struct platform_device *pdev,
 118                                     struct orion_watchdog *dev)
 119 {
 120         int ret;
 121
 122         dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed");
 123         if (!IS_ERR(dev->clk)) {
 124                 ret = clk_prepare_enable(dev->clk);
 125                 if (ret) {
 126                         clk_put(dev->clk);
 127                         return ret;
 128                 }
 129
 130                 atomic_io_modify(dev->reg + TIMER_CTRL,
 131                                 WDT_AXP_FIXED_ENABLE_BIT,
 132                                 WDT_AXP_FIXED_ENABLE_BIT);
 133                 dev->clk_rate = clk_get_rate(dev->clk);
 134
 135                 return 0;
 136         }
 137
 138         /* Mandatory fallback for proper devicetree backward compatibility */
 139         dev->clk = clk_get(&pdev->dev, NULL);
 140         if (IS_ERR(dev->clk))
 141                 return PTR_ERR(dev->clk);
 142
 143         ret = clk_prepare_enable(dev->clk);
 144         if (ret) {
 145                 clk_put(dev->clk);
 146                 return ret;
 147         }
 148
 149         atomic_io_modify(dev->reg + TIMER_CTRL,
 150                         WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT),
 151                         WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT));
 152         dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO;
 153
 154         return 0;
 155 }
 156
 157 static int armadaxp_wdt_clock_init(struct platform_device *pdev,
 158                                    struct orion_watchdog *dev)
 159 {
 160         int ret;
 161
 162         dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed");
 163         if (IS_ERR(dev->clk))
 164                 return PTR_ERR(dev->clk);
 165         ret = clk_prepare_enable(dev->clk);
 166         if (ret) {
 167                 clk_put(dev->clk);
 168                 return ret;
 169         }
 170
 171         /* Enable the fixed watchdog clock input */
 172         atomic_io_modify(dev->reg + TIMER_CTRL,
 173                          WDT_AXP_FIXED_ENABLE_BIT,
 174                          WDT_AXP_FIXED_ENABLE_BIT);
 175
 176         dev->clk_rate = clk_get_rate(dev->clk);
 177         return 0;
 178 }
 179
 180 static int orion_wdt_ping(struct watchdog_device *wdt_dev)
 181 {
 182         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 183         /* Reload watchdog duration */
 184         writel(dev->clk_rate * wdt_dev->timeout,
 185                dev->reg + dev->data->wdt_counter_offset);
 186         return 0;
 187 }
 188
 189 static int armada375_start(struct watchdog_device *wdt_dev)
 190 {
 191         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 192         u32 reg;
 193
 194         /* Set watchdog duration */
 195         writel(dev->clk_rate * wdt_dev->timeout,
 196                dev->reg + dev->data->wdt_counter_offset);
 197
 198         /* Clear the watchdog expiration bit */
 199         atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
 200
 201         /* Enable watchdog timer */
 202         atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
 203                                                 dev->data->wdt_enable_bit);
 204
 205         /* Enable reset on watchdog */
 206         reg = readl(dev->rstout);
 207         reg |= dev->data->rstout_enable_bit;
 208         writel(reg, dev->rstout);
 209
 210         atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit, 0);
 211         return 0;
 212 }
 213
 214 static int armada370_start(struct watchdog_device *wdt_dev)
 215 {
 216         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 217         u32 reg;
 218
 219         /* Set watchdog duration */
 220         writel(dev->clk_rate * wdt_dev->timeout,
 221                dev->reg + dev->data->wdt_counter_offset);
 222
 223         /* Clear the watchdog expiration bit */
 224         atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
 225
 226         /* Enable watchdog timer */
 227         atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
 228                                                 dev->data->wdt_enable_bit);
 229
 230         /* Enable reset on watchdog */
 231         reg = readl(dev->rstout);
 232         reg |= dev->data->rstout_enable_bit;
 233         writel(reg, dev->rstout);
 234         return 0;
 235 }
 236
 237 static int orion_start(struct watchdog_device *wdt_dev)
 238 {
 239         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 240
 241         /* Set watchdog duration */
 242         writel(dev->clk_rate * wdt_dev->timeout,
 243                dev->reg + dev->data->wdt_counter_offset);
 244
 245         /* Enable watchdog timer */
 246         atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
 247                                                 dev->data->wdt_enable_bit);
 248
 249         /* Enable reset on watchdog */
 250         atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit,
 251                                       dev->data->rstout_enable_bit);
 252
 253         return 0;
 254 }
 255
 256 static int orion_wdt_start(struct watchdog_device *wdt_dev)
 257 {
 258         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 259
 260         /* There are some per-SoC quirks to handle */
 261         return dev->data->start(wdt_dev);
 262 }
 263
 264 static int orion_stop(struct watchdog_device *wdt_dev)
 265 {
 266         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 267
 268         /* Disable reset on watchdog */
 269         atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, 0);
 270
 271         /* Disable watchdog timer */
 272         atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
 273
 274         return 0;
 275 }
 276
 277 static int armada375_stop(struct watchdog_device *wdt_dev)
 278 {
 279         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 280         u32 reg;
 281
 282         /* Disable reset on watchdog */
 283         atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit,
 284                                            dev->data->rstout_mask_bit);
 285         reg = readl(dev->rstout);
 286         reg &= ~dev->data->rstout_enable_bit;
 287         writel(reg, dev->rstout);
 288
 289         /* Disable watchdog timer */
 290         atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
 291
 292         return 0;
 293 }
 294
 295 static int armada370_stop(struct watchdog_device *wdt_dev)
 296 {
 297         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 298         u32 reg;
 299
 300         /* Disable reset on watchdog */
 301         reg = readl(dev->rstout);
 302         reg &= ~dev->data->rstout_enable_bit;
 303         writel(reg, dev->rstout);
 304
 305         /* Disable watchdog timer */
 306         atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
 307
 308         return 0;
 309 }
 310
 311 static int orion_wdt_stop(struct watchdog_device *wdt_dev)
 312 {
 313         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 314
 315         return dev->data->stop(wdt_dev);
 316 }
 317
 318 static int orion_enabled(struct orion_watchdog *dev)
 319 {
 320         bool enabled, running;
 321
 322         enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
 323         running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
 324
 325         return enabled && running;
 326 }
 327
 328 static int armada375_enabled(struct orion_watchdog *dev)
 329 {
 330         bool masked, enabled, running;
 331
 332         masked = readl(dev->rstout_mask) & dev->data->rstout_mask_bit;
 333         enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
 334         running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
 335
 336         return !masked && enabled && running;
 337 }
 338
 339 static int orion_wdt_enabled(struct watchdog_device *wdt_dev)
 340 {
 341         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 342
 343         return dev->data->enabled(dev);
 344 }
 345
 346 static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev)
 347 {
 348         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 349         return readl(dev->reg + dev->data->wdt_counter_offset) / dev->clk_rate;
 350 }
 351
 352 static int orion_wdt_set_timeout(struct watchdog_device *wdt_dev,
 353                                  unsigned int timeout)
 354 {
 355         wdt_dev->timeout = timeout;
 356         return 0;
 357 }
 358
 359 static const struct watchdog_info orion_wdt_info = {
 360         .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
 361         .identity = "Orion Watchdog",
 362 };
 363
 364 static const struct watchdog_ops orion_wdt_ops = {
 365         .owner = THIS_MODULE,
 366         .start = orion_wdt_start,
 367         .stop = orion_wdt_stop,
 368         .ping = orion_wdt_ping,
 369         .set_timeout = orion_wdt_set_timeout,
 370         .get_timeleft = orion_wdt_get_timeleft,
 371 };
 372
 373 static irqreturn_t orion_wdt_irq(int irq, void *devid)
 374 {
 375         panic("Watchdog Timeout");
 376         return IRQ_HANDLED;
 377 }
 378
 379 /*
 380  * The original devicetree binding for this driver specified only
 381  * one memory resource, so in order to keep DT backwards compatibility
 382  * we try to fallback to a hardcoded register address, if the resource
 383  * is missing from the devicetree.
 384  */
 385 static void __iomem *orion_wdt_ioremap_rstout(struct platform_device *pdev,
 386                                               phys_addr_t internal_regs)
 387 {
 388         struct resource *res;
 389         phys_addr_t rstout;
 390
 391         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 392         if (res)
 393                 return devm_ioremap(&pdev->dev, res->start,
 394                                     resource_size(res));
 395
 396         rstout = internal_regs + ORION_RSTOUT_MASK_OFFSET;
 397
 398         WARN(1, FW_BUG "falling back to hardcoded RSTOUT reg %pa\n", &rstout);
 399         return devm_ioremap(&pdev->dev, rstout, 0x4);
 400 }
 401
 402 static const struct orion_watchdog_data orion_data = {
 403         .rstout_enable_bit = BIT(1),
 404         .wdt_enable_bit = BIT(4),
 405         .wdt_counter_offset = 0x24,
 406         .clock_init = orion_wdt_clock_init,
 407         .enabled = orion_enabled,
 408         .start = orion_start,
 409         .stop = orion_stop,
 410 };
 411
 412 static const struct orion_watchdog_data armada370_data = {
 413         .rstout_enable_bit = BIT(8),
 414         .wdt_enable_bit = BIT(8),
 415         .wdt_counter_offset = 0x34,
 416         .clock_init = armada370_wdt_clock_init,
 417         .enabled = orion_enabled,
 418         .start = armada370_start,
 419         .stop = armada370_stop,
 420 };
 421
 422 static const struct orion_watchdog_data armadaxp_data = {
 423         .rstout_enable_bit = BIT(8),
 424         .wdt_enable_bit = BIT(8),
 425         .wdt_counter_offset = 0x34,
 426         .clock_init = armadaxp_wdt_clock_init,
 427         .enabled = orion_enabled,
 428         .start = armada370_start,
 429         .stop = armada370_stop,
 430 };
 431
 432 static const struct orion_watchdog_data armada375_data = {
 433         .rstout_enable_bit = BIT(8),
 434         .rstout_mask_bit = BIT(10),
 435         .wdt_enable_bit = BIT(8),
 436         .wdt_counter_offset = 0x34,
 437         .clock_init = armada375_wdt_clock_init,
 438         .enabled = armada375_enabled,
 439         .start = armada375_start,
 440         .stop = armada375_stop,
 441 };
 442
 443 static const struct orion_watchdog_data armada380_data = {
 444         .rstout_enable_bit = BIT(8),
 445         .rstout_mask_bit = BIT(10),
 446         .wdt_enable_bit = BIT(8),
 447         .wdt_counter_offset = 0x34,
 448         .clock_init = armadaxp_wdt_clock_init,
 449         .enabled = armada375_enabled,
 450         .start = armada375_start,
 451         .stop = armada375_stop,
 452 };
 453
 454 static const struct of_device_id orion_wdt_of_match_table[] = {
 455         {
 456                 .compatible = "marvell,orion-wdt",
 457                 .data = &orion_data,
 458         },
 459         {
 460                 .compatible = "marvell,armada-370-wdt",
 461                 .data = &armada370_data,
 462         },
 463         {
 464                 .compatible = "marvell,armada-xp-wdt",
 465                 .data = &armadaxp_data,
 466         },
 467         {
 468                 .compatible = "marvell,armada-375-wdt",
 469                 .data = &armada375_data,
 470         },
 471         {
 472                 .compatible = "marvell,armada-380-wdt",
 473                 .data = &armada380_data,
 474         },
 475         {},
 476 };
 477 MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table);
 478
 479 static int orion_wdt_get_regs(struct platform_device *pdev,
 480                               struct orion_watchdog *dev)
 481 {
 482         struct device_node *node = pdev->dev.of_node;
 483         struct resource *res;
 484
 485         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 486         if (!res)
 487                 return -ENODEV;
 488         dev->reg = devm_ioremap(&pdev->dev, res->start,
 489                                 resource_size(res));
 490         if (!dev->reg)
 491                 return -ENOMEM;
 492
 493         /* Each supported compatible has some RSTOUT register quirk */
 494         if (of_device_is_compatible(node, "marvell,orion-wdt")) {
 495
 496                 dev->rstout = orion_wdt_ioremap_rstout(pdev, res->start &
 497                                                        INTERNAL_REGS_MASK);
 498                 if (!dev->rstout)
 499                         return -ENODEV;
 500
 501         } else if (of_device_is_compatible(node, "marvell,armada-370-wdt") ||
 502                    of_device_is_compatible(node, "marvell,armada-xp-wdt")) {
 503
 504                 /* Dedicated RSTOUT register, can be requested. */
 505                 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 506                 dev->rstout = devm_ioremap_resource(&pdev->dev, res);
 507                 if (IS_ERR(dev->rstout))
 508                         return PTR_ERR(dev->rstout);
 509
 510         } else if (of_device_is_compatible(node, "marvell,armada-375-wdt") ||
 511                    of_device_is_compatible(node, "marvell,armada-380-wdt")) {
 512
 513                 /* Dedicated RSTOUT register, can be requested. */
 514                 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 515                 dev->rstout = devm_ioremap_resource(&pdev->dev, res);
 516                 if (IS_ERR(dev->rstout))
 517                         return PTR_ERR(dev->rstout);
 518
 519                 res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
 520                 if (!res)
 521                         return -ENODEV;
 522                 dev->rstout_mask = devm_ioremap(&pdev->dev, res->start,
 523                                                 resource_size(res));
 524                 if (!dev->rstout_mask)
 525                         return -ENOMEM;
 526
 527         } else {
 528                 return -ENODEV;
 529         }
 530
 531         return 0;
 532 }
 533
 534 static int orion_wdt_probe(struct platform_device *pdev)
 535 {
 536         struct orion_watchdog *dev;
 537         const struct of_device_id *match;
 538         unsigned int wdt_max_duration;  /* (seconds) */
 539         int ret, irq;
 540
 541         dev = devm_kzalloc(&pdev->dev, sizeof(struct orion_watchdog),
 542                            GFP_KERNEL);
 543         if (!dev)
 544                 return -ENOMEM;
 545
 546         match = of_match_device(orion_wdt_of_match_table, &pdev->dev);
 547         if (!match)
 548                 /* Default legacy match */
 549                 match = &orion_wdt_of_match_table[0];
 550
 551         dev->wdt.info = &orion_wdt_info;
 552         dev->wdt.ops = &orion_wdt_ops;
 553         dev->wdt.min_timeout = 1;
 554         dev->data = match->data;
 555
 556         ret = orion_wdt_get_regs(pdev, dev);
 557         if (ret)
 558                 return ret;
 559
 560         ret = dev->data->clock_init(pdev, dev);
 561         if (ret) {
 562                 dev_err(&pdev->dev, "cannot initialize clock\n");
 563                 return ret;
 564         }
 565
 566         wdt_max_duration = WDT_MAX_CYCLE_COUNT / dev->clk_rate;
 567
 568         dev->wdt.timeout = wdt_max_duration;
 569         dev->wdt.max_timeout = wdt_max_duration;
 570         dev->wdt.parent = &pdev->dev;
 571         watchdog_init_timeout(&dev->wdt, heartbeat, &pdev->dev);
 572
 573         platform_set_drvdata(pdev, &dev->wdt);
 574         watchdog_set_drvdata(&dev->wdt, dev);
 575
 576         /*
 577          * Let's make sure the watchdog is fully stopped, unless it's
 578          * explicitly enabled. This may be the case if the module was
 579          * removed and re-inserted, or if the bootloader explicitly
 580          * set a running watchdog before booting the kernel.
 581          */
 582         if (!orion_wdt_enabled(&dev->wdt))
 583                 orion_wdt_stop(&dev->wdt);
 584         else
 585                 set_bit(WDOG_HW_RUNNING, &dev->wdt.status);
 586
 587         /* Request the IRQ only after the watchdog is disabled */
 588         irq = platform_get_irq(pdev, 0);
 589         if (irq > 0) {
 590                 /*
 591                  * Not all supported platforms specify an interrupt for the
 592                  * watchdog, so let's make it optional.
 593                  */
 594                 ret = devm_request_irq(&pdev->dev, irq, orion_wdt_irq, 0,
 595                                        pdev->name, dev);
 596                 if (ret < 0) {
 597                         dev_err(&pdev->dev, "failed to request IRQ\n");
 598                         goto disable_clk;
 599                 }
 600         }
 601
 602         watchdog_set_nowayout(&dev->wdt, nowayout);
 603         ret = watchdog_register_device(&dev->wdt);
 604         if (ret)
 605                 goto disable_clk;
 606
 607         pr_info("Initial timeout %d sec%s\n",
 608                 dev->wdt.timeout, nowayout ? ", nowayout" : "");
 609         return 0;
 610
 611 disable_clk:
 612         clk_disable_unprepare(dev->clk);
 613         clk_put(dev->clk);
 614         return ret;
 615 }
 616
 617 static int orion_wdt_remove(struct platform_device *pdev)
 618 {
 619         struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
 620         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 621
 622         watchdog_unregister_device(wdt_dev);
 623         clk_disable_unprepare(dev->clk);
 624         clk_put(dev->clk);
 625         return 0;
 626 }
 627
 628 static void orion_wdt_shutdown(struct platform_device *pdev)
 629 {
 630         struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
 631         orion_wdt_stop(wdt_dev);
 632 }
 633
 634 static struct platform_driver orion_wdt_driver = {
 635         .probe          = orion_wdt_probe,
 636         .remove         = orion_wdt_remove,
 637         .shutdown       = orion_wdt_shutdown,
 638         .driver         = {
 639                 .name   = "orion_wdt",
 640                 .of_match_table = orion_wdt_of_match_table,
 641         },
 642 };
 643
 644 module_platform_driver(orion_wdt_driver);
 645
 646 MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
 647 MODULE_DESCRIPTION("Orion Processor Watchdog");
 648
 649 module_param(heartbeat, int, 0);
 650 MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
 651
 652 module_param(nowayout, bool, 0);
 653 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 654                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 655
 656 MODULE_LICENSE("GPL v2");
 657 MODULE_ALIAS("platform:orion_wdt");