1 /* 2 * sp5100_tco : TCO timer driver for sp5100 chipsets 3 * 4 * (c) Copyright 2009 Google Inc., All Rights Reserved. 5 * 6 * Based on i8xx_tco.c: 7 * (c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights 8 * Reserved. 9 * http://www.kernelconcepts.de 10 * 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License 13 * as published by the Free Software Foundation; either version 14 * 2 of the License, or (at your option) any later version. 15 * 16 * See AMD Publication 43009 "AMD SB700/710/750 Register Reference Guide" 17 */ 18 19 /* 20 * Includes, defines, variables, module parameters, ... 21 */ 22 23 #include <linux/module.h> 24 #include <linux/moduleparam.h> 25 #include <linux/types.h> 26 #include <linux/miscdevice.h> 27 #include <linux/watchdog.h> 28 #include <linux/init.h> 29 #include <linux/fs.h> 30 #include <linux/pci.h> 31 #include <linux/ioport.h> 32 #include <linux/platform_device.h> 33 #include <linux/uaccess.h> 34 #include <linux/io.h> 35 36 #include "sp5100_tco.h" 37 38 /* Module and version information */ 39 #define TCO_VERSION "0.01" 40 #define TCO_MODULE_NAME "SP5100 TCO timer" 41 #define TCO_DRIVER_NAME TCO_MODULE_NAME ", v" TCO_VERSION 42 #define PFX TCO_MODULE_NAME ": " 43 44 /* internal variables */ 45 static void __iomem *tcobase; 46 static unsigned int pm_iobase; 47 static DEFINE_SPINLOCK(tco_lock); /* Guards the hardware */ 48 static unsigned long timer_alive; 49 static char tco_expect_close; 50 static struct pci_dev *sp5100_tco_pci; 51 52 /* the watchdog platform device */ 53 static struct platform_device *sp5100_tco_platform_device; 54 55 /* module parameters */ 56 57 #define WATCHDOG_HEARTBEAT 60 /* 60 sec default heartbeat. */ 58 static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */ 59 module_param(heartbeat, int, 0); 60 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (default=" 61 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")"); 62 63 static int nowayout = WATCHDOG_NOWAYOUT; 64 module_param(nowayout, int, 0); 65 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started" 66 " (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 67 68 /* 69 * Some TCO specific functions 70 */ 71 static void tco_timer_start(void) 72 { 73 u32 val; 74 unsigned long flags; 75 76 spin_lock_irqsave(&tco_lock, flags); 77 val = readl(SP5100_WDT_CONTROL(tcobase)); 78 val |= SP5100_WDT_START_STOP_BIT; 79 writel(val, SP5100_WDT_CONTROL(tcobase)); 80 spin_unlock_irqrestore(&tco_lock, flags); 81 } 82 83 static void tco_timer_stop(void) 84 { 85 u32 val; 86 unsigned long flags; 87 88 spin_lock_irqsave(&tco_lock, flags); 89 val = readl(SP5100_WDT_CONTROL(tcobase)); 90 val &= ~SP5100_WDT_START_STOP_BIT; 91 writel(val, SP5100_WDT_CONTROL(tcobase)); 92 spin_unlock_irqrestore(&tco_lock, flags); 93 } 94 95 static void tco_timer_keepalive(void) 96 { 97 u32 val; 98 unsigned long flags; 99 100 spin_lock_irqsave(&tco_lock, flags); 101 val = readl(SP5100_WDT_CONTROL(tcobase)); 102 val |= SP5100_WDT_TRIGGER_BIT; 103 writel(val, SP5100_WDT_CONTROL(tcobase)); 104 spin_unlock_irqrestore(&tco_lock, flags); 105 } 106 107 static int tco_timer_set_heartbeat(int t) 108 { 109 unsigned long flags; 110 111 if (t < 0 || t > 0xffff) 112 return -EINVAL; 113 114 /* Write new heartbeat to watchdog */ 115 spin_lock_irqsave(&tco_lock, flags); 116 writel(t, SP5100_WDT_COUNT(tcobase)); 117 spin_unlock_irqrestore(&tco_lock, flags); 118 119 heartbeat = t; 120 return 0; 121 } 122 123 /* 124 * /dev/watchdog handling 125 */ 126 127 static int sp5100_tco_open(struct inode *inode, struct file *file) 128 { 129 /* /dev/watchdog can only be opened once */ 130 if (test_and_set_bit(0, &timer_alive)) 131 return -EBUSY; 132 133 /* Reload and activate timer */ 134 tco_timer_start(); 135 tco_timer_keepalive(); 136 return nonseekable_open(inode, file); 137 } 138 139 static int sp5100_tco_release(struct inode *inode, struct file *file) 140 { 141 /* Shut off the timer. */ 142 if (tco_expect_close == 42) { 143 tco_timer_stop(); 144 } else { 145 printk(KERN_CRIT PFX 146 "Unexpected close, not stopping watchdog!\n"); 147 tco_timer_keepalive(); 148 } 149 clear_bit(0, &timer_alive); 150 tco_expect_close = 0; 151 return 0; 152 } 153 154 static ssize_t sp5100_tco_write(struct file *file, const char __user *data, 155 size_t len, loff_t *ppos) 156 { 157 /* See if we got the magic character 'V' and reload the timer */ 158 if (len) { 159 if (!nowayout) { 160 size_t i; 161 162 /* note: just in case someone wrote the magic character 163 * five months ago... */ 164 tco_expect_close = 0; 165 166 /* scan to see whether or not we got the magic character 167 */ 168 for (i = 0; i != len; i++) { 169 char c; 170 if (get_user(c, data + i)) 171 return -EFAULT; 172 if (c == 'V') 173 tco_expect_close = 42; 174 } 175 } 176 177 /* someone wrote to us, we should reload the timer */ 178 tco_timer_keepalive(); 179 } 180 return len; 181 } 182 183 static long sp5100_tco_ioctl(struct file *file, unsigned int cmd, 184 unsigned long arg) 185 { 186 int new_options, retval = -EINVAL; 187 int new_heartbeat; 188 void __user *argp = (void __user *)arg; 189 int __user *p = argp; 190 static const struct watchdog_info ident = { 191 .options = WDIOF_SETTIMEOUT | 192 WDIOF_KEEPALIVEPING | 193 WDIOF_MAGICCLOSE, 194 .firmware_version = 0, 195 .identity = TCO_MODULE_NAME, 196 }; 197 198 switch (cmd) { 199 case WDIOC_GETSUPPORT: 200 return copy_to_user(argp, &ident, 201 sizeof(ident)) ? -EFAULT : 0; 202 case WDIOC_GETSTATUS: 203 case WDIOC_GETBOOTSTATUS: 204 return put_user(0, p); 205 case WDIOC_SETOPTIONS: 206 if (get_user(new_options, p)) 207 return -EFAULT; 208 if (new_options & WDIOS_DISABLECARD) { 209 tco_timer_stop(); 210 retval = 0; 211 } 212 if (new_options & WDIOS_ENABLECARD) { 213 tco_timer_start(); 214 tco_timer_keepalive(); 215 retval = 0; 216 } 217 return retval; 218 case WDIOC_KEEPALIVE: 219 tco_timer_keepalive(); 220 return 0; 221 case WDIOC_SETTIMEOUT: 222 if (get_user(new_heartbeat, p)) 223 return -EFAULT; 224 if (tco_timer_set_heartbeat(new_heartbeat)) 225 return -EINVAL; 226 tco_timer_keepalive(); 227 /* Fall through */ 228 case WDIOC_GETTIMEOUT: 229 return put_user(heartbeat, p); 230 default: 231 return -ENOTTY; 232 } 233 } 234 235 /* 236 * Kernel Interfaces 237 */ 238 239 static const struct file_operations sp5100_tco_fops = { 240 .owner = THIS_MODULE, 241 .llseek = no_llseek, 242 .write = sp5100_tco_write, 243 .unlocked_ioctl = sp5100_tco_ioctl, 244 .open = sp5100_tco_open, 245 .release = sp5100_tco_release, 246 }; 247 248 static struct miscdevice sp5100_tco_miscdev = { 249 .minor = WATCHDOG_MINOR, 250 .name = "watchdog", 251 .fops = &sp5100_tco_fops, 252 }; 253 254 /* 255 * Data for PCI driver interface 256 * 257 * This data only exists for exporting the supported 258 * PCI ids via MODULE_DEVICE_TABLE. We do not actually 259 * register a pci_driver, because someone else might 260 * want to register another driver on the same PCI id. 261 */ 262 static struct pci_device_id sp5100_tco_pci_tbl[] = { 263 { PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS, PCI_ANY_ID, 264 PCI_ANY_ID, }, 265 { 0, }, /* End of list */ 266 }; 267 MODULE_DEVICE_TABLE(pci, sp5100_tco_pci_tbl); 268 269 /* 270 * Init & exit routines 271 */ 272 273 static unsigned char __devinit sp5100_tco_setupdevice(void) 274 { 275 struct pci_dev *dev = NULL; 276 u32 val; 277 278 /* Match the PCI device */ 279 for_each_pci_dev(dev) { 280 if (pci_match_id(sp5100_tco_pci_tbl, dev) != NULL) { 281 sp5100_tco_pci = dev; 282 break; 283 } 284 } 285 286 if (!sp5100_tco_pci) 287 return 0; 288 289 /* Request the IO ports used by this driver */ 290 pm_iobase = SP5100_IO_PM_INDEX_REG; 291 if (!request_region(pm_iobase, SP5100_PM_IOPORTS_SIZE, "SP5100 TCO")) { 292 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", 293 pm_iobase); 294 goto exit; 295 } 296 297 /* Find the watchdog base address. */ 298 outb(SP5100_PM_WATCHDOG_BASE3, SP5100_IO_PM_INDEX_REG); 299 val = inb(SP5100_IO_PM_DATA_REG); 300 outb(SP5100_PM_WATCHDOG_BASE2, SP5100_IO_PM_INDEX_REG); 301 val = val << 8 | inb(SP5100_IO_PM_DATA_REG); 302 outb(SP5100_PM_WATCHDOG_BASE1, SP5100_IO_PM_INDEX_REG); 303 val = val << 8 | inb(SP5100_IO_PM_DATA_REG); 304 outb(SP5100_PM_WATCHDOG_BASE0, SP5100_IO_PM_INDEX_REG); 305 /* Low three bits of BASE0 are reserved. */ 306 val = val << 8 | (inb(SP5100_IO_PM_DATA_REG) & 0xf8); 307 308 tcobase = ioremap(val, SP5100_WDT_MEM_MAP_SIZE); 309 if (tcobase == 0) { 310 printk(KERN_ERR PFX "failed to get tcobase address\n"); 311 goto unreg_region; 312 } 313 314 /* Enable watchdog decode bit */ 315 pci_read_config_dword(sp5100_tco_pci, 316 SP5100_PCI_WATCHDOG_MISC_REG, 317 &val); 318 319 val |= SP5100_PCI_WATCHDOG_DECODE_EN; 320 321 pci_write_config_dword(sp5100_tco_pci, 322 SP5100_PCI_WATCHDOG_MISC_REG, 323 val); 324 325 /* Enable Watchdog timer and set the resolution to 1 sec. */ 326 outb(SP5100_PM_WATCHDOG_CONTROL, SP5100_IO_PM_INDEX_REG); 327 val = inb(SP5100_IO_PM_DATA_REG); 328 val |= SP5100_PM_WATCHDOG_SECOND_RES; 329 val &= ~SP5100_PM_WATCHDOG_DISABLE; 330 outb(val, SP5100_IO_PM_DATA_REG); 331 332 /* Check that the watchdog action is set to reset the system. */ 333 val = readl(SP5100_WDT_CONTROL(tcobase)); 334 val &= ~SP5100_PM_WATCHDOG_ACTION_RESET; 335 writel(val, SP5100_WDT_CONTROL(tcobase)); 336 337 /* Set a reasonable heartbeat before we stop the timer */ 338 tco_timer_set_heartbeat(heartbeat); 339 340 /* 341 * Stop the TCO before we change anything so we don't race with 342 * a zeroed timer. 343 */ 344 tco_timer_stop(); 345 346 /* Done */ 347 return 1; 348 349 iounmap(tcobase); 350 unreg_region: 351 release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE); 352 exit: 353 return 0; 354 } 355 356 static int __devinit sp5100_tco_init(struct platform_device *dev) 357 { 358 int ret; 359 u32 val; 360 361 /* Check whether or not the hardware watchdog is there. If found, then 362 * set it up. 363 */ 364 if (!sp5100_tco_setupdevice()) 365 return -ENODEV; 366 367 /* Check to see if last reboot was due to watchdog timeout */ 368 printk(KERN_INFO PFX "Watchdog reboot %sdetected.\n", 369 readl(SP5100_WDT_CONTROL(tcobase)) & SP5100_PM_WATCHDOG_FIRED ? 370 "" : "not "); 371 372 /* Clear out the old status */ 373 val = readl(SP5100_WDT_CONTROL(tcobase)); 374 val &= ~SP5100_PM_WATCHDOG_FIRED; 375 writel(val, SP5100_WDT_CONTROL(tcobase)); 376 377 /* 378 * Check that the heartbeat value is within it's range. 379 * If not, reset to the default. 380 */ 381 if (tco_timer_set_heartbeat(heartbeat)) { 382 heartbeat = WATCHDOG_HEARTBEAT; 383 tco_timer_set_heartbeat(heartbeat); 384 } 385 386 ret = misc_register(&sp5100_tco_miscdev); 387 if (ret != 0) { 388 printk(KERN_ERR PFX "cannot register miscdev on minor=" 389 "%d (err=%d)\n", 390 WATCHDOG_MINOR, ret); 391 goto exit; 392 } 393 394 clear_bit(0, &timer_alive); 395 396 printk(KERN_INFO PFX "initialized (0x%p). heartbeat=%d sec" 397 " (nowayout=%d)\n", 398 tcobase, heartbeat, nowayout); 399 400 return 0; 401 402 exit: 403 iounmap(tcobase); 404 release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE); 405 return ret; 406 } 407 408 static void __devexit sp5100_tco_cleanup(void) 409 { 410 /* Stop the timer before we leave */ 411 if (!nowayout) 412 tco_timer_stop(); 413 414 /* Deregister */ 415 misc_deregister(&sp5100_tco_miscdev); 416 iounmap(tcobase); 417 release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE); 418 } 419 420 static int __devexit sp5100_tco_remove(struct platform_device *dev) 421 { 422 if (tcobase) 423 sp5100_tco_cleanup(); 424 return 0; 425 } 426 427 static void sp5100_tco_shutdown(struct platform_device *dev) 428 { 429 tco_timer_stop(); 430 } 431 432 static struct platform_driver sp5100_tco_driver = { 433 .probe = sp5100_tco_init, 434 .remove = __devexit_p(sp5100_tco_remove), 435 .shutdown = sp5100_tco_shutdown, 436 .driver = { 437 .owner = THIS_MODULE, 438 .name = TCO_MODULE_NAME, 439 }, 440 }; 441 442 static int __init sp5100_tco_init_module(void) 443 { 444 int err; 445 446 printk(KERN_INFO PFX "SP5100 TCO WatchDog Timer Driver v%s\n", 447 TCO_VERSION); 448 449 err = platform_driver_register(&sp5100_tco_driver); 450 if (err) 451 return err; 452 453 sp5100_tco_platform_device = platform_device_register_simple( 454 TCO_MODULE_NAME, -1, NULL, 0); 455 if (IS_ERR(sp5100_tco_platform_device)) { 456 err = PTR_ERR(sp5100_tco_platform_device); 457 goto unreg_platform_driver; 458 } 459 460 return 0; 461 462 unreg_platform_driver: 463 platform_driver_unregister(&sp5100_tco_driver); 464 return err; 465 } 466 467 static void __exit sp5100_tco_cleanup_module(void) 468 { 469 platform_device_unregister(sp5100_tco_platform_device); 470 platform_driver_unregister(&sp5100_tco_driver); 471 printk(KERN_INFO PFX "SP5100 TCO Watchdog Module Unloaded.\n"); 472 } 473 474 module_init(sp5100_tco_init_module); 475 module_exit(sp5100_tco_cleanup_module); 476 477 MODULE_AUTHOR("Priyanka Gupta"); 478 MODULE_DESCRIPTION("TCO timer driver for SP5100 chipset"); 479 MODULE_LICENSE("GPL"); 480 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 481