drivers/watchdog/sp5100_tco.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      sp5100_tco :    TCO timer driver for sp5100 chipsets
   4  *
   5  *      (c) Copyright 2009 Google Inc., All Rights Reserved.
   6  *
   7  *      Based on i8xx_tco.c:
   8  *      (c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights
   9  *      Reserved.
  10  *                              https://www.kernelconcepts.de
  11  *
  12  *      See AMD Publication 43009 "AMD SB700/710/750 Register Reference Guide",
  13  *          AMD Publication 44413 "AMD SP5100 Register Reference Guide"
  14  *          AMD Publication 45482 "AMD SB800-Series Southbridges Register
  15  *                                                            Reference Guide"
  16  *          AMD Publication 48751 "BIOS and Kernel Developer’s Guide (BKDG)
  17  *                              for AMD Family 16h Models 00h-0Fh Processors"
  18  *          AMD Publication 51192 "AMD Bolton FCH Register Reference Guide"
  19  *          AMD Publication 52740 "BIOS and Kernel Developer’s Guide (BKDG)
  20  *                              for AMD Family 16h Models 30h-3Fh Processors"
  21  *          AMD Publication 55570-B1-PUB "Processor Programming Reference (PPR)
  22  *                              for AMD Family 17h Model 18h, Revision B1
  23  *                              Processors (PUB)
  24  *          AMD Publication 55772-A1-PUB "Processor Programming Reference (PPR)
  25  *                              for AMD Family 17h Model 20h, Revision A1
  26  *                              Processors (PUB)
  27  */
  28
  29 /*
  30  *      Includes, defines, variables, module parameters, ...
  31  */
  32
  33 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  34
  35 #include <linux/init.h>
  36 #include <linux/io.h>
  37 #include <linux/ioport.h>
  38 #include <linux/module.h>
  39 #include <linux/moduleparam.h>
  40 #include <linux/pci.h>
  41 #include <linux/platform_device.h>
  42 #include <linux/types.h>
  43 #include <linux/watchdog.h>
  44
  45 #include "sp5100_tco.h"
  46
  47 #define TCO_DRIVER_NAME "sp5100-tco"
  48
  49 /* internal variables */
  50
  51 enum tco_reg_layout {
  52         sp5100, sb800, efch
  53 };
  54
  55 struct sp5100_tco {
  56         struct watchdog_device wdd;
  57         void __iomem *tcobase;
  58         enum tco_reg_layout tco_reg_layout;
  59 };
  60
  61 /* the watchdog platform device */
  62 static struct platform_device *sp5100_tco_platform_device;
  63 /* the associated PCI device */
  64 static struct pci_dev *sp5100_tco_pci;
  65
  66 /* module parameters */
  67
  68 #define WATCHDOG_HEARTBEAT 60   /* 60 sec default heartbeat. */
  69 static int heartbeat = WATCHDOG_HEARTBEAT;  /* in seconds */
  70 module_param(heartbeat, int, 0);
  71 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (default="
  72                  __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
  73
  74 static bool nowayout = WATCHDOG_NOWAYOUT;
  75 module_param(nowayout, bool, 0);
  76 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started."
  77                 " (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  78
  79 /*
  80  * Some TCO specific functions
  81  */
  82
  83 static enum tco_reg_layout tco_reg_layout(struct pci_dev *dev)
  84 {
  85         if (dev->vendor == PCI_VENDOR_ID_ATI &&
  86             dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
  87             dev->revision < 0x40) {
  88                 return sp5100;
  89         } else if (dev->vendor == PCI_VENDOR_ID_AMD &&
  90             ((dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS &&
  91              dev->revision >= 0x41) ||
  92             (dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS &&
  93              dev->revision >= 0x49))) {
  94                 return efch;
  95         }
  96         return sb800;
  97 }
  98
  99 static int tco_timer_start(struct watchdog_device *wdd)
 100 {
 101         struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
 102         u32 val;
 103
 104         val = readl(SP5100_WDT_CONTROL(tco->tcobase));
 105         val |= SP5100_WDT_START_STOP_BIT;
 106         writel(val, SP5100_WDT_CONTROL(tco->tcobase));
 107
 108         return 0;
 109 }
 110
 111 static int tco_timer_stop(struct watchdog_device *wdd)
 112 {
 113         struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
 114         u32 val;
 115
 116         val = readl(SP5100_WDT_CONTROL(tco->tcobase));
 117         val &= ~SP5100_WDT_START_STOP_BIT;
 118         writel(val, SP5100_WDT_CONTROL(tco->tcobase));
 119
 120         return 0;
 121 }
 122
 123 static int tco_timer_ping(struct watchdog_device *wdd)
 124 {
 125         struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
 126         u32 val;
 127
 128         val = readl(SP5100_WDT_CONTROL(tco->tcobase));
 129         val |= SP5100_WDT_TRIGGER_BIT;
 130         writel(val, SP5100_WDT_CONTROL(tco->tcobase));
 131
 132         return 0;
 133 }
 134
 135 static int tco_timer_set_timeout(struct watchdog_device *wdd,
 136                                  unsigned int t)
 137 {
 138         struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
 139
 140         /* Write new heartbeat to watchdog */
 141         writel(t, SP5100_WDT_COUNT(tco->tcobase));
 142
 143         wdd->timeout = t;
 144
 145         return 0;
 146 }
 147
 148 static unsigned int tco_timer_get_timeleft(struct watchdog_device *wdd)
 149 {
 150         struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
 151
 152         return readl(SP5100_WDT_COUNT(tco->tcobase));
 153 }
 154
 155 static u8 sp5100_tco_read_pm_reg8(u8 index)
 156 {
 157         outb(index, SP5100_IO_PM_INDEX_REG);
 158         return inb(SP5100_IO_PM_DATA_REG);
 159 }
 160
 161 static void sp5100_tco_update_pm_reg8(u8 index, u8 reset, u8 set)
 162 {
 163         u8 val;
 164
 165         outb(index, SP5100_IO_PM_INDEX_REG);
 166         val = inb(SP5100_IO_PM_DATA_REG);
 167         val &= reset;
 168         val |= set;
 169         outb(val, SP5100_IO_PM_DATA_REG);
 170 }
 171
 172 static void tco_timer_enable(struct sp5100_tco *tco)
 173 {
 174         u32 val;
 175
 176         switch (tco->tco_reg_layout) {
 177         case sb800:
 178                 /* For SB800 or later */
 179                 /* Set the Watchdog timer resolution to 1 sec */
 180                 sp5100_tco_update_pm_reg8(SB800_PM_WATCHDOG_CONFIG,
 181                                           0xff, SB800_PM_WATCHDOG_SECOND_RES);
 182
 183                 /* Enable watchdog decode bit and watchdog timer */
 184                 sp5100_tco_update_pm_reg8(SB800_PM_WATCHDOG_CONTROL,
 185                                           ~SB800_PM_WATCHDOG_DISABLE,
 186                                           SB800_PCI_WATCHDOG_DECODE_EN);
 187                 break;
 188         case sp5100:
 189                 /* For SP5100 or SB7x0 */
 190                 /* Enable watchdog decode bit */
 191                 pci_read_config_dword(sp5100_tco_pci,
 192                                       SP5100_PCI_WATCHDOG_MISC_REG,
 193                                       &val);
 194
 195                 val |= SP5100_PCI_WATCHDOG_DECODE_EN;
 196
 197                 pci_write_config_dword(sp5100_tco_pci,
 198                                        SP5100_PCI_WATCHDOG_MISC_REG,
 199                                        val);
 200
 201                 /* Enable Watchdog timer and set the resolution to 1 sec */
 202                 sp5100_tco_update_pm_reg8(SP5100_PM_WATCHDOG_CONTROL,
 203                                           ~SP5100_PM_WATCHDOG_DISABLE,
 204                                           SP5100_PM_WATCHDOG_SECOND_RES);
 205                 break;
 206         case efch:
 207                 /* Set the Watchdog timer resolution to 1 sec and enable */
 208                 sp5100_tco_update_pm_reg8(EFCH_PM_DECODEEN3,
 209                                           ~EFCH_PM_WATCHDOG_DISABLE,
 210                                           EFCH_PM_DECODEEN_SECOND_RES);
 211                 break;
 212         }
 213 }
 214
 215 static u32 sp5100_tco_read_pm_reg32(u8 index)
 216 {
 217         u32 val = 0;
 218         int i;
 219
 220         for (i = 3; i >= 0; i--)
 221                 val = (val << 8) + sp5100_tco_read_pm_reg8(index + i);
 222
 223         return val;
 224 }
 225
 226 static int sp5100_tco_setupdevice(struct device *dev,
 227                                   struct watchdog_device *wdd)
 228 {
 229         struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
 230         const char *dev_name;
 231         u32 mmio_addr = 0, val;
 232         int ret;
 233
 234         /* Request the IO ports used by this driver */
 235         if (!request_muxed_region(SP5100_IO_PM_INDEX_REG,
 236                                   SP5100_PM_IOPORTS_SIZE, "sp5100_tco")) {
 237                 dev_err(dev, "I/O address 0x%04x already in use\n",
 238                         SP5100_IO_PM_INDEX_REG);
 239                 return -EBUSY;
 240         }
 241
 242         /*
 243          * Determine type of southbridge chipset.
 244          */
 245         switch (tco->tco_reg_layout) {
 246         case sp5100:
 247                 dev_name = SP5100_DEVNAME;
 248                 mmio_addr = sp5100_tco_read_pm_reg32(SP5100_PM_WATCHDOG_BASE) &
 249                                                                 0xfffffff8;
 250                 break;
 251         case sb800:
 252                 dev_name = SB800_DEVNAME;
 253                 mmio_addr = sp5100_tco_read_pm_reg32(SB800_PM_WATCHDOG_BASE) &
 254                                                                 0xfffffff8;
 255                 break;
 256         case efch:
 257                 dev_name = SB800_DEVNAME;
 258                 /*
 259                  * On Family 17h devices, the EFCH_PM_DECODEEN_WDT_TMREN bit of
 260                  * EFCH_PM_DECODEEN not only enables the EFCH_PM_WDT_ADDR memory
 261                  * region, it also enables the watchdog itself.
 262                  */
 263                 if (boot_cpu_data.x86 == 0x17) {
 264                         val = sp5100_tco_read_pm_reg8(EFCH_PM_DECODEEN);
 265                         if (!(val & EFCH_PM_DECODEEN_WDT_TMREN)) {
 266                                 sp5100_tco_update_pm_reg8(EFCH_PM_DECODEEN, 0xff,
 267                                                           EFCH_PM_DECODEEN_WDT_TMREN);
 268                         }
 269                 }
 270                 val = sp5100_tco_read_pm_reg8(EFCH_PM_DECODEEN);
 271                 if (val & EFCH_PM_DECODEEN_WDT_TMREN)
 272                         mmio_addr = EFCH_PM_WDT_ADDR;
 273                 break;
 274         default:
 275                 return -ENODEV;
 276         }
 277
 278         /* Check MMIO address conflict */
 279         if (!mmio_addr ||
 280             !devm_request_mem_region(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE,
 281                                      dev_name)) {
 282                 if (mmio_addr)
 283                         dev_dbg(dev, "MMIO address 0x%08x already in use\n",
 284                                 mmio_addr);
 285                 switch (tco->tco_reg_layout) {
 286                 case sp5100:
 287                         /*
 288                          * Secondly, Find the watchdog timer MMIO address
 289                          * from SBResource_MMIO register.
 290                          */
 291                         /* Read SBResource_MMIO from PCI config(PCI_Reg: 9Ch) */
 292                         pci_read_config_dword(sp5100_tco_pci,
 293                                               SP5100_SB_RESOURCE_MMIO_BASE,
 294                                               &mmio_addr);
 295                         if ((mmio_addr & (SB800_ACPI_MMIO_DECODE_EN |
 296                                           SB800_ACPI_MMIO_SEL)) !=
 297                                                   SB800_ACPI_MMIO_DECODE_EN) {
 298                                 ret = -ENODEV;
 299                                 goto unreg_region;
 300                         }
 301                         mmio_addr &= ~0xFFF;
 302                         mmio_addr += SB800_PM_WDT_MMIO_OFFSET;
 303                         break;
 304                 case sb800:
 305                         /* Read SBResource_MMIO from AcpiMmioEn(PM_Reg: 24h) */
 306                         mmio_addr =
 307                                 sp5100_tco_read_pm_reg32(SB800_PM_ACPI_MMIO_EN);
 308                         if ((mmio_addr & (SB800_ACPI_MMIO_DECODE_EN |
 309                                           SB800_ACPI_MMIO_SEL)) !=
 310                                                   SB800_ACPI_MMIO_DECODE_EN) {
 311                                 ret = -ENODEV;
 312                                 goto unreg_region;
 313                         }
 314                         mmio_addr &= ~0xFFF;
 315                         mmio_addr += SB800_PM_WDT_MMIO_OFFSET;
 316                         break;
 317                 case efch:
 318                         val = sp5100_tco_read_pm_reg8(EFCH_PM_ISACONTROL);
 319                         if (!(val & EFCH_PM_ISACONTROL_MMIOEN)) {
 320                                 ret = -ENODEV;
 321                                 goto unreg_region;
 322                         }
 323                         mmio_addr = EFCH_PM_ACPI_MMIO_ADDR +
 324                                     EFCH_PM_ACPI_MMIO_WDT_OFFSET;
 325                         break;
 326                 }
 327                 dev_dbg(dev, "Got 0x%08x from SBResource_MMIO register\n",
 328                         mmio_addr);
 329                 if (!devm_request_mem_region(dev, mmio_addr,
 330                                              SP5100_WDT_MEM_MAP_SIZE,
 331                                              dev_name)) {
 332                         dev_dbg(dev, "MMIO address 0x%08x already in use\n",
 333                                 mmio_addr);
 334                         ret = -EBUSY;
 335                         goto unreg_region;
 336                 }
 337         }
 338
 339         tco->tcobase = devm_ioremap(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE);
 340         if (!tco->tcobase) {
 341                 dev_err(dev, "failed to get tcobase address\n");
 342                 ret = -ENOMEM;
 343                 goto unreg_region;
 344         }
 345
 346         dev_info(dev, "Using 0x%08x for watchdog MMIO address\n", mmio_addr);
 347
 348         /* Setup the watchdog timer */
 349         tco_timer_enable(tco);
 350
 351         val = readl(SP5100_WDT_CONTROL(tco->tcobase));
 352         if (val & SP5100_WDT_DISABLED) {
 353                 dev_err(dev, "Watchdog hardware is disabled\n");
 354                 ret = -ENODEV;
 355                 goto unreg_region;
 356         }
 357
 358         /*
 359          * Save WatchDogFired status, because WatchDogFired flag is
 360          * cleared here.
 361          */
 362         if (val & SP5100_WDT_FIRED)
 363                 wdd->bootstatus = WDIOF_CARDRESET;
 364         /* Set watchdog action to reset the system */
 365         val &= ~SP5100_WDT_ACTION_RESET;
 366         writel(val, SP5100_WDT_CONTROL(tco->tcobase));
 367
 368         /* Set a reasonable heartbeat before we stop the timer */
 369         tco_timer_set_timeout(wdd, wdd->timeout);
 370
 371         /*
 372          * Stop the TCO before we change anything so we don't race with
 373          * a zeroed timer.
 374          */
 375         tco_timer_stop(wdd);
 376
 377         release_region(SP5100_IO_PM_INDEX_REG, SP5100_PM_IOPORTS_SIZE);
 378
 379         return 0;
 380
 381 unreg_region:
 382         release_region(SP5100_IO_PM_INDEX_REG, SP5100_PM_IOPORTS_SIZE);
 383         return ret;
 384 }
 385
 386 static struct watchdog_info sp5100_tco_wdt_info = {
 387         .identity = "SP5100 TCO timer",
 388         .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
 389 };
 390
 391 static const struct watchdog_ops sp5100_tco_wdt_ops = {
 392         .owner = THIS_MODULE,
 393         .start = tco_timer_start,
 394         .stop = tco_timer_stop,
 395         .ping = tco_timer_ping,
 396         .set_timeout = tco_timer_set_timeout,
 397         .get_timeleft = tco_timer_get_timeleft,
 398 };
 399
 400 static int sp5100_tco_probe(struct platform_device *pdev)
 401 {
 402         struct device *dev = &pdev->dev;
 403         struct watchdog_device *wdd;
 404         struct sp5100_tco *tco;
 405         int ret;
 406
 407         tco = devm_kzalloc(dev, sizeof(*tco), GFP_KERNEL);
 408         if (!tco)
 409                 return -ENOMEM;
 410
 411         tco->tco_reg_layout = tco_reg_layout(sp5100_tco_pci);
 412
 413         wdd = &tco->wdd;
 414         wdd->parent = dev;
 415         wdd->info = &sp5100_tco_wdt_info;
 416         wdd->ops = &sp5100_tco_wdt_ops;
 417         wdd->timeout = WATCHDOG_HEARTBEAT;
 418         wdd->min_timeout = 1;
 419         wdd->max_timeout = 0xffff;
 420
 421         watchdog_init_timeout(wdd, heartbeat, NULL);
 422         watchdog_set_nowayout(wdd, nowayout);
 423         watchdog_stop_on_reboot(wdd);
 424         watchdog_stop_on_unregister(wdd);
 425         watchdog_set_drvdata(wdd, tco);
 426
 427         ret = sp5100_tco_setupdevice(dev, wdd);
 428         if (ret)
 429                 return ret;
 430
 431         ret = devm_watchdog_register_device(dev, wdd);
 432         if (ret)
 433                 return ret;
 434
 435         /* Show module parameters */
 436         dev_info(dev, "initialized. heartbeat=%d sec (nowayout=%d)\n",
 437                  wdd->timeout, nowayout);
 438
 439         return 0;
 440 }
 441
 442 static struct platform_driver sp5100_tco_driver = {
 443         .probe          = sp5100_tco_probe,
 444         .driver         = {
 445                 .name   = TCO_DRIVER_NAME,
 446         },
 447 };
 448
 449 /*
 450  * Data for PCI driver interface
 451  *
 452  * This data only exists for exporting the supported
 453  * PCI ids via MODULE_DEVICE_TABLE.  We do not actually
 454  * register a pci_driver, because someone else might
 455  * want to register another driver on the same PCI id.
 456  */
 457 static const struct pci_device_id sp5100_tco_pci_tbl[] = {
 458         { PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS, PCI_ANY_ID,
 459           PCI_ANY_ID, },
 460         { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_HUDSON2_SMBUS, PCI_ANY_ID,
 461           PCI_ANY_ID, },
 462         { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS, PCI_ANY_ID,
 463           PCI_ANY_ID, },
 464         { 0, },                 /* End of list */
 465 };
 466 MODULE_DEVICE_TABLE(pci, sp5100_tco_pci_tbl);
 467
 468 static int __init sp5100_tco_init(void)
 469 {
 470         struct pci_dev *dev = NULL;
 471         int err;
 472
 473         /* Match the PCI device */
 474         for_each_pci_dev(dev) {
 475                 if (pci_match_id(sp5100_tco_pci_tbl, dev) != NULL) {
 476                         sp5100_tco_pci = dev;
 477                         break;
 478                 }
 479         }
 480
 481         if (!sp5100_tco_pci)
 482                 return -ENODEV;
 483
 484         pr_info("SP5100/SB800 TCO WatchDog Timer Driver\n");
 485
 486         err = platform_driver_register(&sp5100_tco_driver);
 487         if (err)
 488                 return err;
 489
 490         sp5100_tco_platform_device =
 491                 platform_device_register_simple(TCO_DRIVER_NAME, -1, NULL, 0);
 492         if (IS_ERR(sp5100_tco_platform_device)) {
 493                 err = PTR_ERR(sp5100_tco_platform_device);
 494                 goto unreg_platform_driver;
 495         }
 496
 497         return 0;
 498
 499 unreg_platform_driver:
 500         platform_driver_unregister(&sp5100_tco_driver);
 501         return err;
 502 }
 503
 504 static void __exit sp5100_tco_exit(void)
 505 {
 506         platform_device_unregister(sp5100_tco_platform_device);
 507         platform_driver_unregister(&sp5100_tco_driver);
 508 }
 509
 510 module_init(sp5100_tco_init);
 511 module_exit(sp5100_tco_exit);
 512
 513 MODULE_AUTHOR("Priyanka Gupta");
 514 MODULE_DESCRIPTION("TCO timer driver for SP5100/SB800 chipset");
 515 MODULE_LICENSE("GPL");