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 armadaxp_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                 return PTR_ERR(dev->clk);
 125         ret = clk_prepare_enable(dev->clk);
 126         if (ret) {
 127                 clk_put(dev->clk);
 128                 return ret;
 129         }
 130
 131         /* Enable the fixed watchdog clock input */
 132         atomic_io_modify(dev->reg + TIMER_CTRL,
 133                          WDT_AXP_FIXED_ENABLE_BIT,
 134                          WDT_AXP_FIXED_ENABLE_BIT);
 135
 136         dev->clk_rate = clk_get_rate(dev->clk);
 137         return 0;
 138 }
 139
 140 static int orion_wdt_ping(struct watchdog_device *wdt_dev)
 141 {
 142         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 143         /* Reload watchdog duration */
 144         writel(dev->clk_rate * wdt_dev->timeout,
 145                dev->reg + dev->data->wdt_counter_offset);
 146         return 0;
 147 }
 148
 149 static int armada375_start(struct watchdog_device *wdt_dev)
 150 {
 151         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 152         u32 reg;
 153
 154         /* Set watchdog duration */
 155         writel(dev->clk_rate * wdt_dev->timeout,
 156                dev->reg + dev->data->wdt_counter_offset);
 157
 158         /* Clear the watchdog expiration bit */
 159         atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
 160
 161         /* Enable watchdog timer */
 162         atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
 163                                                 dev->data->wdt_enable_bit);
 164
 165         /* Enable reset on watchdog */
 166         reg = readl(dev->rstout);
 167         reg |= dev->data->rstout_enable_bit;
 168         writel(reg, dev->rstout);
 169
 170         atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit, 0);
 171         return 0;
 172 }
 173
 174 static int armada370_start(struct watchdog_device *wdt_dev)
 175 {
 176         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 177         u32 reg;
 178
 179         /* Set watchdog duration */
 180         writel(dev->clk_rate * wdt_dev->timeout,
 181                dev->reg + dev->data->wdt_counter_offset);
 182
 183         /* Clear the watchdog expiration bit */
 184         atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
 185
 186         /* Enable watchdog timer */
 187         atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
 188                                                 dev->data->wdt_enable_bit);
 189
 190         /* Enable reset on watchdog */
 191         reg = readl(dev->rstout);
 192         reg |= dev->data->rstout_enable_bit;
 193         writel(reg, dev->rstout);
 194         return 0;
 195 }
 196
 197 static int orion_start(struct watchdog_device *wdt_dev)
 198 {
 199         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 200
 201         /* Set watchdog duration */
 202         writel(dev->clk_rate * wdt_dev->timeout,
 203                dev->reg + dev->data->wdt_counter_offset);
 204
 205         /* Enable watchdog timer */
 206         atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
 207                                                 dev->data->wdt_enable_bit);
 208
 209         /* Enable reset on watchdog */
 210         atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit,
 211                                       dev->data->rstout_enable_bit);
 212
 213         return 0;
 214 }
 215
 216 static int orion_wdt_start(struct watchdog_device *wdt_dev)
 217 {
 218         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 219
 220         /* There are some per-SoC quirks to handle */
 221         return dev->data->start(wdt_dev);
 222 }
 223
 224 static int orion_stop(struct watchdog_device *wdt_dev)
 225 {
 226         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 227
 228         /* Disable reset on watchdog */
 229         atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, 0);
 230
 231         /* Disable watchdog timer */
 232         atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
 233
 234         return 0;
 235 }
 236
 237 static int armada375_stop(struct watchdog_device *wdt_dev)
 238 {
 239         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 240         u32 reg;
 241
 242         /* Disable reset on watchdog */
 243         atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit,
 244                                            dev->data->rstout_mask_bit);
 245         reg = readl(dev->rstout);
 246         reg &= ~dev->data->rstout_enable_bit;
 247         writel(reg, dev->rstout);
 248
 249         /* Disable watchdog timer */
 250         atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
 251
 252         return 0;
 253 }
 254
 255 static int armada370_stop(struct watchdog_device *wdt_dev)
 256 {
 257         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 258         u32 reg;
 259
 260         /* Disable reset on watchdog */
 261         reg = readl(dev->rstout);
 262         reg &= ~dev->data->rstout_enable_bit;
 263         writel(reg, dev->rstout);
 264
 265         /* Disable watchdog timer */
 266         atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
 267
 268         return 0;
 269 }
 270
 271 static int orion_wdt_stop(struct watchdog_device *wdt_dev)
 272 {
 273         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 274
 275         return dev->data->stop(wdt_dev);
 276 }
 277
 278 static int orion_enabled(struct orion_watchdog *dev)
 279 {
 280         bool enabled, running;
 281
 282         enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
 283         running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
 284
 285         return enabled && running;
 286 }
 287
 288 static int armada375_enabled(struct orion_watchdog *dev)
 289 {
 290         bool masked, enabled, running;
 291
 292         masked = readl(dev->rstout_mask) & dev->data->rstout_mask_bit;
 293         enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
 294         running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
 295
 296         return !masked && enabled && running;
 297 }
 298
 299 static int orion_wdt_enabled(struct watchdog_device *wdt_dev)
 300 {
 301         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 302
 303         return dev->data->enabled(dev);
 304 }
 305
 306 static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev)
 307 {
 308         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 309         return readl(dev->reg + dev->data->wdt_counter_offset) / dev->clk_rate;
 310 }
 311
 312 static int orion_wdt_set_timeout(struct watchdog_device *wdt_dev,
 313                                  unsigned int timeout)
 314 {
 315         wdt_dev->timeout = timeout;
 316         return 0;
 317 }
 318
 319 static const struct watchdog_info orion_wdt_info = {
 320         .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
 321         .identity = "Orion Watchdog",
 322 };
 323
 324 static const struct watchdog_ops orion_wdt_ops = {
 325         .owner = THIS_MODULE,
 326         .start = orion_wdt_start,
 327         .stop = orion_wdt_stop,
 328         .ping = orion_wdt_ping,
 329         .set_timeout = orion_wdt_set_timeout,
 330         .get_timeleft = orion_wdt_get_timeleft,
 331 };
 332
 333 static irqreturn_t orion_wdt_irq(int irq, void *devid)
 334 {
 335         panic("Watchdog Timeout");
 336         return IRQ_HANDLED;
 337 }
 338
 339 /*
 340  * The original devicetree binding for this driver specified only
 341  * one memory resource, so in order to keep DT backwards compatibility
 342  * we try to fallback to a hardcoded register address, if the resource
 343  * is missing from the devicetree.
 344  */
 345 static void __iomem *orion_wdt_ioremap_rstout(struct platform_device *pdev,
 346                                               phys_addr_t internal_regs)
 347 {
 348         struct resource *res;
 349         phys_addr_t rstout;
 350
 351         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 352         if (res)
 353                 return devm_ioremap(&pdev->dev, res->start,
 354                                     resource_size(res));
 355
 356         rstout = internal_regs + ORION_RSTOUT_MASK_OFFSET;
 357
 358         WARN(1, FW_BUG "falling back to harcoded RSTOUT reg %pa\n", &rstout);
 359         return devm_ioremap(&pdev->dev, rstout, 0x4);
 360 }
 361
 362 static const struct orion_watchdog_data orion_data = {
 363         .rstout_enable_bit = BIT(1),
 364         .wdt_enable_bit = BIT(4),
 365         .wdt_counter_offset = 0x24,
 366         .clock_init = orion_wdt_clock_init,
 367         .enabled = orion_enabled,
 368         .start = orion_start,
 369         .stop = orion_stop,
 370 };
 371
 372 static const struct orion_watchdog_data armada370_data = {
 373         .rstout_enable_bit = BIT(8),
 374         .wdt_enable_bit = BIT(8),
 375         .wdt_counter_offset = 0x34,
 376         .clock_init = armada370_wdt_clock_init,
 377         .enabled = orion_enabled,
 378         .start = armada370_start,
 379         .stop = armada370_stop,
 380 };
 381
 382 static const struct orion_watchdog_data armadaxp_data = {
 383         .rstout_enable_bit = BIT(8),
 384         .wdt_enable_bit = BIT(8),
 385         .wdt_counter_offset = 0x34,
 386         .clock_init = armadaxp_wdt_clock_init,
 387         .enabled = orion_enabled,
 388         .start = armada370_start,
 389         .stop = armada370_stop,
 390 };
 391
 392 static const struct orion_watchdog_data armada375_data = {
 393         .rstout_enable_bit = BIT(8),
 394         .rstout_mask_bit = BIT(10),
 395         .wdt_enable_bit = BIT(8),
 396         .wdt_counter_offset = 0x34,
 397         .clock_init = armada370_wdt_clock_init,
 398         .enabled = armada375_enabled,
 399         .start = armada375_start,
 400         .stop = armada375_stop,
 401 };
 402
 403 static const struct orion_watchdog_data armada380_data = {
 404         .rstout_enable_bit = BIT(8),
 405         .rstout_mask_bit = BIT(10),
 406         .wdt_enable_bit = BIT(8),
 407         .wdt_counter_offset = 0x34,
 408         .clock_init = armadaxp_wdt_clock_init,
 409         .enabled = armada375_enabled,
 410         .start = armada375_start,
 411         .stop = armada375_stop,
 412 };
 413
 414 static const struct of_device_id orion_wdt_of_match_table[] = {
 415         {
 416                 .compatible = "marvell,orion-wdt",
 417                 .data = &orion_data,
 418         },
 419         {
 420                 .compatible = "marvell,armada-370-wdt",
 421                 .data = &armada370_data,
 422         },
 423         {
 424                 .compatible = "marvell,armada-xp-wdt",
 425                 .data = &armadaxp_data,
 426         },
 427         {
 428                 .compatible = "marvell,armada-375-wdt",
 429                 .data = &armada375_data,
 430         },
 431         {
 432                 .compatible = "marvell,armada-380-wdt",
 433                 .data = &armada380_data,
 434         },
 435         {},
 436 };
 437 MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table);
 438
 439 static int orion_wdt_get_regs(struct platform_device *pdev,
 440                               struct orion_watchdog *dev)
 441 {
 442         struct device_node *node = pdev->dev.of_node;
 443         struct resource *res;
 444
 445         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 446         if (!res)
 447                 return -ENODEV;
 448         dev->reg = devm_ioremap(&pdev->dev, res->start,
 449                                 resource_size(res));
 450         if (!dev->reg)
 451                 return -ENOMEM;
 452
 453         /* Each supported compatible has some RSTOUT register quirk */
 454         if (of_device_is_compatible(node, "marvell,orion-wdt")) {
 455
 456                 dev->rstout = orion_wdt_ioremap_rstout(pdev, res->start &
 457                                                        INTERNAL_REGS_MASK);
 458                 if (!dev->rstout)
 459                         return -ENODEV;
 460
 461         } else if (of_device_is_compatible(node, "marvell,armada-370-wdt") ||
 462                    of_device_is_compatible(node, "marvell,armada-xp-wdt")) {
 463
 464                 /* Dedicated RSTOUT register, can be requested. */
 465                 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 466                 dev->rstout = devm_ioremap_resource(&pdev->dev, res);
 467                 if (IS_ERR(dev->rstout))
 468                         return PTR_ERR(dev->rstout);
 469
 470         } else if (of_device_is_compatible(node, "marvell,armada-375-wdt") ||
 471                    of_device_is_compatible(node, "marvell,armada-380-wdt")) {
 472
 473                 /* Dedicated RSTOUT register, can be requested. */
 474                 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 475                 dev->rstout = devm_ioremap_resource(&pdev->dev, res);
 476                 if (IS_ERR(dev->rstout))
 477                         return PTR_ERR(dev->rstout);
 478
 479                 res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
 480                 if (!res)
 481                         return -ENODEV;
 482                 dev->rstout_mask = devm_ioremap(&pdev->dev, res->start,
 483                                                 resource_size(res));
 484                 if (!dev->rstout_mask)
 485                         return -ENOMEM;
 486
 487         } else {
 488                 return -ENODEV;
 489         }
 490
 491         return 0;
 492 }
 493
 494 static int orion_wdt_probe(struct platform_device *pdev)
 495 {
 496         struct orion_watchdog *dev;
 497         const struct of_device_id *match;
 498         unsigned int wdt_max_duration;  /* (seconds) */
 499         int ret, irq;
 500
 501         dev = devm_kzalloc(&pdev->dev, sizeof(struct orion_watchdog),
 502                            GFP_KERNEL);
 503         if (!dev)
 504                 return -ENOMEM;
 505
 506         match = of_match_device(orion_wdt_of_match_table, &pdev->dev);
 507         if (!match)
 508                 /* Default legacy match */
 509                 match = &orion_wdt_of_match_table[0];
 510
 511         dev->wdt.info = &orion_wdt_info;
 512         dev->wdt.ops = &orion_wdt_ops;
 513         dev->wdt.min_timeout = 1;
 514         dev->data = match->data;
 515
 516         ret = orion_wdt_get_regs(pdev, dev);
 517         if (ret)
 518                 return ret;
 519
 520         ret = dev->data->clock_init(pdev, dev);
 521         if (ret) {
 522                 dev_err(&pdev->dev, "cannot initialize clock\n");
 523                 return ret;
 524         }
 525
 526         wdt_max_duration = WDT_MAX_CYCLE_COUNT / dev->clk_rate;
 527
 528         dev->wdt.timeout = wdt_max_duration;
 529         dev->wdt.max_timeout = wdt_max_duration;
 530         watchdog_init_timeout(&dev->wdt, heartbeat, &pdev->dev);
 531
 532         platform_set_drvdata(pdev, &dev->wdt);
 533         watchdog_set_drvdata(&dev->wdt, dev);
 534
 535         /*
 536          * Let's make sure the watchdog is fully stopped, unless it's
 537          * explicitly enabled. This may be the case if the module was
 538          * removed and re-insterted, or if the bootloader explicitly
 539          * set a running watchdog before booting the kernel.
 540          */
 541         if (!orion_wdt_enabled(&dev->wdt))
 542                 orion_wdt_stop(&dev->wdt);
 543
 544         /* Request the IRQ only after the watchdog is disabled */
 545         irq = platform_get_irq(pdev, 0);
 546         if (irq > 0) {
 547                 /*
 548                  * Not all supported platforms specify an interrupt for the
 549                  * watchdog, so let's make it optional.
 550                  */
 551                 ret = devm_request_irq(&pdev->dev, irq, orion_wdt_irq, 0,
 552                                        pdev->name, dev);
 553                 if (ret < 0) {
 554                         dev_err(&pdev->dev, "failed to request IRQ\n");
 555                         goto disable_clk;
 556                 }
 557         }
 558
 559         watchdog_set_nowayout(&dev->wdt, nowayout);
 560         ret = watchdog_register_device(&dev->wdt);
 561         if (ret)
 562                 goto disable_clk;
 563
 564         pr_info("Initial timeout %d sec%s\n",
 565                 dev->wdt.timeout, nowayout ? ", nowayout" : "");
 566         return 0;
 567
 568 disable_clk:
 569         clk_disable_unprepare(dev->clk);
 570         clk_put(dev->clk);
 571         return ret;
 572 }
 573
 574 static int orion_wdt_remove(struct platform_device *pdev)
 575 {
 576         struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
 577         struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 578
 579         watchdog_unregister_device(wdt_dev);
 580         clk_disable_unprepare(dev->clk);
 581         clk_put(dev->clk);
 582         return 0;
 583 }
 584
 585 static void orion_wdt_shutdown(struct platform_device *pdev)
 586 {
 587         struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
 588         orion_wdt_stop(wdt_dev);
 589 }
 590
 591 static struct platform_driver orion_wdt_driver = {
 592         .probe          = orion_wdt_probe,
 593         .remove         = orion_wdt_remove,
 594         .shutdown       = orion_wdt_shutdown,
 595         .driver         = {
 596                 .owner  = THIS_MODULE,
 597                 .name   = "orion_wdt",
 598                 .of_match_table = orion_wdt_of_match_table,
 599         },
 600 };
 601
 602 module_platform_driver(orion_wdt_driver);
 603
 604 MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
 605 MODULE_DESCRIPTION("Orion Processor Watchdog");
 606
 607 module_param(heartbeat, int, 0);
 608 MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
 609
 610 module_param(nowayout, bool, 0);
 611 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 612                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 613
 614 MODULE_LICENSE("GPL");
 615 MODULE_ALIAS("platform:orion_wdt");