1/* 2 * sch311x_wdt.c - Driver for the SCH311x Super-I/O chips 3 * integrated watchdog. 4 * 5 * (c) Copyright 2008 Wim Van Sebroeck <wim@iguana.be>. 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 * 12 * Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor 13 * provide warranty for any of this software. This material is 14 * provided "AS-IS" and at no charge. 15 */ 16 17/* 18 * Includes, defines, variables, module parameters, ... 19 */ 20 21/* Includes */ 22#include <linux/module.h> /* For module specific items */ 23#include <linux/moduleparam.h> /* For new moduleparam's */ 24#include <linux/types.h> /* For standard types (like size_t) */ 25#include <linux/errno.h> /* For the -ENODEV/... values */ 26#include <linux/kernel.h> /* For printk/... */ 27#include <linux/miscdevice.h> /* For MODULE_ALIAS_MISCDEV 28 (WATCHDOG_MINOR) */ 29#include <linux/watchdog.h> /* For the watchdog specific items */ 30#include <linux/init.h> /* For __init/__exit/... */ 31#include <linux/fs.h> /* For file operations */ 32#include <linux/platform_device.h> /* For platform_driver framework */ 33#include <linux/ioport.h> /* For io-port access */ 34#include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */ 35#include <linux/uaccess.h> /* For copy_to_user/put_user/... */ 36#include <linux/io.h> /* For inb/outb/... */ 37 38/* Module and version information */ 39#define DRV_NAME "sch311x_wdt" 40#define PFX DRV_NAME ": " 41 42/* Runtime registers */ 43#define RESGEN 0x1d 44#define GP60 0x47 45#define WDT_TIME_OUT 0x65 46#define WDT_VAL 0x66 47#define WDT_CFG 0x67 48#define WDT_CTRL 0x68 49 50/* internal variables */ 51static unsigned long sch311x_wdt_is_open; 52static char sch311x_wdt_expect_close; 53static struct platform_device *sch311x_wdt_pdev; 54 55static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e, 0x00 }; 56 57static struct { /* The devices private data */ 58 /* the Runtime Register base address */ 59 unsigned short runtime_reg; 60 /* The card's boot status */ 61 int boot_status; 62 /* the lock for io operations */ 63 spinlock_t io_lock; 64} sch311x_wdt_data; 65 66/* Module load parameters */ 67static unsigned short force_id; 68module_param(force_id, ushort, 0); 69MODULE_PARM_DESC(force_id, "Override the detected device ID"); 70 71static unsigned short therm_trip; 72module_param(therm_trip, ushort, 0); 73MODULE_PARM_DESC(therm_trip, "Should a ThermTrip trigger the reset generator"); 74 75#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ 76static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ 77module_param(timeout, int, 0); 78MODULE_PARM_DESC(timeout, 79 "Watchdog timeout in seconds. 1<= timeout <=15300, default=" 80 __MODULE_STRING(WATCHDOG_TIMEOUT) "."); 81 82static int nowayout = WATCHDOG_NOWAYOUT; 83module_param(nowayout, int, 0); 84MODULE_PARM_DESC(nowayout, 85 "Watchdog cannot be stopped once started (default=" 86 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 87 88/* 89 * Super-IO functions 90 */ 91 92static inline void sch311x_sio_enter(int sio_config_port) 93{ 94 outb(0x55, sio_config_port); 95} 96 97static inline void sch311x_sio_exit(int sio_config_port) 98{ 99 outb(0xaa, sio_config_port); 100} 101 102static inline int sch311x_sio_inb(int sio_config_port, int reg) 103{ 104 outb(reg, sio_config_port); 105 return inb(sio_config_port + 1); 106} 107 108static inline void sch311x_sio_outb(int sio_config_port, int reg, int val) 109{ 110 outb(reg, sio_config_port); 111 outb(val, sio_config_port + 1); 112} 113 114/* 115 * Watchdog Operations 116 */ 117 118static void sch311x_wdt_set_timeout(int t) 119{ 120 unsigned char timeout_unit = 0x80; 121 122 /* When new timeout is bigger then 255 seconds, we will use minutes */ 123 if (t > 255) { 124 timeout_unit = 0; 125 t /= 60; 126 } 127 128 /* -- Watchdog Timeout -- 129 * Bit 0-6 (Reserved) 130 * Bit 7 WDT Time-out Value Units Select 131 * (0 = Minutes, 1 = Seconds) 132 */ 133 outb(timeout_unit, sch311x_wdt_data.runtime_reg + WDT_TIME_OUT); 134 135 /* -- Watchdog Timer Time-out Value -- 136 * Bit 0-7 Binary coded units (0=Disabled, 1..255) 137 */ 138 outb(t, sch311x_wdt_data.runtime_reg + WDT_VAL); 139} 140 141static void sch311x_wdt_start(void) 142{ 143 spin_lock(&sch311x_wdt_data.io_lock); 144 145 /* set watchdog's timeout */ 146 sch311x_wdt_set_timeout(timeout); 147 /* enable the watchdog */ 148 /* -- General Purpose I/O Bit 6.0 -- 149 * Bit 0, In/Out: 0 = Output, 1 = Input 150 * Bit 1, Polarity: 0 = No Invert, 1 = Invert 151 * Bit 2-3, Function select: 00 = GPI/O, 01 = LED1, 11 = WDT, 152 * 10 = Either Edge Triggered Intr.4 153 * Bit 4-6 (Reserved) 154 * Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain 155 */ 156 outb(0x0e, sch311x_wdt_data.runtime_reg + GP60); 157 158 spin_unlock(&sch311x_wdt_data.io_lock); 159 160} 161 162static void sch311x_wdt_stop(void) 163{ 164 spin_lock(&sch311x_wdt_data.io_lock); 165 166 /* stop the watchdog */ 167 outb(0x01, sch311x_wdt_data.runtime_reg + GP60); 168 /* disable timeout by setting it to 0 */ 169 sch311x_wdt_set_timeout(0); 170 171 spin_unlock(&sch311x_wdt_data.io_lock); 172} 173 174static void sch311x_wdt_keepalive(void) 175{ 176 spin_lock(&sch311x_wdt_data.io_lock); 177 sch311x_wdt_set_timeout(timeout); 178 spin_unlock(&sch311x_wdt_data.io_lock); 179} 180 181static int sch311x_wdt_set_heartbeat(int t) 182{ 183 if (t < 1 || t > (255*60)) 184 return -EINVAL; 185 186 /* When new timeout is bigger then 255 seconds, 187 * we will round up to minutes (with a max of 255) */ 188 if (t > 255) 189 t = (((t - 1) / 60) + 1) * 60; 190 191 timeout = t; 192 return 0; 193} 194 195static void sch311x_wdt_get_status(int *status) 196{ 197 unsigned char new_status; 198 199 *status = 0; 200 201 spin_lock(&sch311x_wdt_data.io_lock); 202 203 /* -- Watchdog timer control -- 204 * Bit 0 Status Bit: 0 = Timer counting, 1 = Timeout occured 205 * Bit 1 Reserved 206 * Bit 2 Force Timeout: 1 = Forces WD timeout event (self-cleaning) 207 * Bit 3 P20 Force Timeout enabled: 208 * 0 = P20 activity does not generate the WD timeout event 209 * 1 = P20 Allows rising edge of P20, from the keyboard 210 * controller, to force the WD timeout event. 211 * Bit 4-7 Reserved 212 */ 213 new_status = inb(sch311x_wdt_data.runtime_reg + WDT_CTRL); 214 if (new_status & 0x01) 215 *status |= WDIOF_CARDRESET; 216 217 spin_unlock(&sch311x_wdt_data.io_lock); 218} 219 220/* 221 * /dev/watchdog handling 222 */ 223 224static ssize_t sch311x_wdt_write(struct file *file, const char __user *buf, 225 size_t count, loff_t *ppos) 226{ 227 if (count) { 228 if (!nowayout) { 229 size_t i; 230 231 sch311x_wdt_expect_close = 0; 232 233 for (i = 0; i != count; i++) { 234 char c; 235 if (get_user(c, buf + i)) 236 return -EFAULT; 237 if (c == 'V') 238 sch311x_wdt_expect_close = 42; 239 } 240 } 241 sch311x_wdt_keepalive(); 242 } 243 return count; 244} 245 246static long sch311x_wdt_ioctl(struct file *file, unsigned int cmd, 247 unsigned long arg) 248{ 249 int status; 250 int new_timeout; 251 void __user *argp = (void __user *)arg; 252 int __user *p = argp; 253 static const struct watchdog_info ident = { 254 .options = WDIOF_KEEPALIVEPING | 255 WDIOF_SETTIMEOUT | 256 WDIOF_MAGICCLOSE, 257 .firmware_version = 1, 258 .identity = DRV_NAME, 259 }; 260 261 switch (cmd) { 262 case WDIOC_GETSUPPORT: 263 if (copy_to_user(argp, &ident, sizeof(ident))) 264 return -EFAULT; 265 break; 266 267 case WDIOC_GETSTATUS: 268 { 269 sch311x_wdt_get_status(&status); 270 return put_user(status, p); 271 } 272 case WDIOC_GETBOOTSTATUS: 273 return put_user(sch311x_wdt_data.boot_status, p); 274 275 case WDIOC_SETOPTIONS: 276 { 277 int options, retval = -EINVAL; 278 279 if (get_user(options, p)) 280 return -EFAULT; 281 if (options & WDIOS_DISABLECARD) { 282 sch311x_wdt_stop(); 283 retval = 0; 284 } 285 if (options & WDIOS_ENABLECARD) { 286 sch311x_wdt_start(); 287 retval = 0; 288 } 289 return retval; 290 } 291 case WDIOC_KEEPALIVE: 292 sch311x_wdt_keepalive(); 293 break; 294 295 case WDIOC_SETTIMEOUT: 296 if (get_user(new_timeout, p)) 297 return -EFAULT; 298 if (sch311x_wdt_set_heartbeat(new_timeout)) 299 return -EINVAL; 300 sch311x_wdt_keepalive(); 301 /* Fall */ 302 case WDIOC_GETTIMEOUT: 303 return put_user(timeout, p); 304 default: 305 return -ENOTTY; 306 } 307 return 0; 308} 309 310static int sch311x_wdt_open(struct inode *inode, struct file *file) 311{ 312 if (test_and_set_bit(0, &sch311x_wdt_is_open)) 313 return -EBUSY; 314 /* 315 * Activate 316 */ 317 sch311x_wdt_start(); 318 return nonseekable_open(inode, file); 319} 320 321static int sch311x_wdt_close(struct inode *inode, struct file *file) 322{ 323 if (sch311x_wdt_expect_close == 42) { 324 sch311x_wdt_stop(); 325 } else { 326 printk(KERN_CRIT PFX 327 "Unexpected close, not stopping watchdog!\n"); 328 sch311x_wdt_keepalive(); 329 } 330 clear_bit(0, &sch311x_wdt_is_open); 331 sch311x_wdt_expect_close = 0; 332 return 0; 333} 334 335/* 336 * Kernel Interfaces 337 */ 338 339static const struct file_operations sch311x_wdt_fops = { 340 .owner = THIS_MODULE, 341 .llseek = no_llseek, 342 .write = sch311x_wdt_write, 343 .unlocked_ioctl = sch311x_wdt_ioctl, 344 .open = sch311x_wdt_open, 345 .release = sch311x_wdt_close, 346}; 347 348static struct miscdevice sch311x_wdt_miscdev = { 349 .minor = WATCHDOG_MINOR, 350 .name = "watchdog", 351 .fops = &sch311x_wdt_fops, 352}; 353 354/* 355 * Init & exit routines 356 */ 357 358static int __devinit sch311x_wdt_probe(struct platform_device *pdev) 359{ 360 struct device *dev = &pdev->dev; 361 unsigned char val; 362 int err; 363 364 spin_lock_init(&sch311x_wdt_data.io_lock); 365 366 if (!request_region(sch311x_wdt_data.runtime_reg + RESGEN, 1, 367 DRV_NAME)) { 368 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n", 369 sch311x_wdt_data.runtime_reg + RESGEN, 370 sch311x_wdt_data.runtime_reg + RESGEN); 371 err = -EBUSY; 372 goto exit; 373 } 374 375 if (!request_region(sch311x_wdt_data.runtime_reg + GP60, 1, DRV_NAME)) { 376 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n", 377 sch311x_wdt_data.runtime_reg + GP60, 378 sch311x_wdt_data.runtime_reg + GP60); 379 err = -EBUSY; 380 goto exit_release_region; 381 } 382 383 if (!request_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4, 384 DRV_NAME)) { 385 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n", 386 sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 387 sch311x_wdt_data.runtime_reg + WDT_CTRL); 388 err = -EBUSY; 389 goto exit_release_region2; 390 } 391 392 /* Make sure that the watchdog is not running */ 393 sch311x_wdt_stop(); 394 395 /* Disable keyboard and mouse interaction and interrupt */ 396 /* -- Watchdog timer configuration -- 397 * Bit 0 Reserved 398 * Bit 1 Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr. 399 * Bit 2 Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr 400 * Bit 3 Reserved 401 * Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled, 402 * 0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15) 403 */ 404 outb(0, sch311x_wdt_data.runtime_reg + WDT_CFG); 405 406 /* Check that the heartbeat value is within it's range ; 407 * if not reset to the default */ 408 if (sch311x_wdt_set_heartbeat(timeout)) { 409 sch311x_wdt_set_heartbeat(WATCHDOG_TIMEOUT); 410 dev_info(dev, "timeout value must be 1<=x<=15300, using %d\n", 411 timeout); 412 } 413 414 /* Get status at boot */ 415 sch311x_wdt_get_status(&sch311x_wdt_data.boot_status); 416 417 /* enable watchdog */ 418 /* -- Reset Generator -- 419 * Bit 0 Enable Watchdog Timer Generation: 0* = Enabled, 1 = Disabled 420 * Bit 1 Thermtrip Source Select: O* = No Source, 1 = Source 421 * Bit 2 WDT2_CTL: WDT input bit 422 * Bit 3-7 Reserved 423 */ 424 outb(0, sch311x_wdt_data.runtime_reg + RESGEN); 425 val = therm_trip ? 0x06 : 0x04; 426 outb(val, sch311x_wdt_data.runtime_reg + RESGEN); 427 428 sch311x_wdt_miscdev.parent = dev; 429 430 err = misc_register(&sch311x_wdt_miscdev); 431 if (err != 0) { 432 dev_err(dev, "cannot register miscdev on minor=%d (err=%d)\n", 433 WATCHDOG_MINOR, err); 434 goto exit_release_region3; 435 } 436 437 dev_info(dev, 438 "SMSC SCH311x WDT initialized. timeout=%d sec (nowayout=%d)\n", 439 timeout, nowayout); 440 441 return 0; 442 443exit_release_region3: 444 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4); 445exit_release_region2: 446 release_region(sch311x_wdt_data.runtime_reg + GP60, 1); 447exit_release_region: 448 release_region(sch311x_wdt_data.runtime_reg + RESGEN, 1); 449 sch311x_wdt_data.runtime_reg = 0; 450exit: 451 return err; 452} 453 454static int __devexit sch311x_wdt_remove(struct platform_device *pdev) 455{ 456 /* Stop the timer before we leave */ 457 if (!nowayout) 458 sch311x_wdt_stop(); 459 460 /* Deregister */ 461 misc_deregister(&sch311x_wdt_miscdev); 462 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4); 463 release_region(sch311x_wdt_data.runtime_reg + GP60, 1); 464 release_region(sch311x_wdt_data.runtime_reg + RESGEN, 1); 465 sch311x_wdt_data.runtime_reg = 0; 466 return 0; 467} 468 469static void sch311x_wdt_shutdown(struct platform_device *dev) 470{ 471 /* Turn the WDT off if we have a soft shutdown */ 472 sch311x_wdt_stop(); 473} 474 475#define sch311x_wdt_suspend NULL 476#define sch311x_wdt_resume NULL 477 478static struct platform_driver sch311x_wdt_driver = { 479 .probe = sch311x_wdt_probe, 480 .remove = __devexit_p(sch311x_wdt_remove), 481 .shutdown = sch311x_wdt_shutdown, 482 .suspend = sch311x_wdt_suspend, 483 .resume = sch311x_wdt_resume, 484 .driver = { 485 .owner = THIS_MODULE, 486 .name = DRV_NAME, 487 }, 488}; 489 490static int __init sch311x_detect(int sio_config_port, unsigned short *addr) 491{ 492 int err = 0, reg; 493 unsigned short base_addr; 494 unsigned char dev_id; 495 496 sch311x_sio_enter(sio_config_port); 497 498 /* Check device ID. We currently know about: 499 * SCH3112 (0x7c), SCH3114 (0x7d), and SCH3116 (0x7f). */ 500 reg = force_id ? force_id : sch311x_sio_inb(sio_config_port, 0x20); 501 if (!(reg == 0x7c || reg == 0x7d || reg == 0x7f)) { 502 err = -ENODEV; 503 goto exit; 504 } 505 dev_id = reg == 0x7c ? 2 : reg == 0x7d ? 4 : 6; 506 507 /* Select logical device A (runtime registers) */ 508 sch311x_sio_outb(sio_config_port, 0x07, 0x0a); 509 510 /* Check if Logical Device Register is currently active */ 511 if (sch311x_sio_inb(sio_config_port, 0x30) && 0x01 == 0) 512 printk(KERN_INFO PFX "Seems that LDN 0x0a is not active...\n"); 513 514 /* Get the base address of the runtime registers */ 515 base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) | 516 sch311x_sio_inb(sio_config_port, 0x61); 517 if (!base_addr) { 518 printk(KERN_ERR PFX "Base address not set.\n"); 519 err = -ENODEV; 520 goto exit; 521 } 522 *addr = base_addr; 523 524 printk(KERN_INFO PFX "Found an SMSC SCH311%d chip at 0x%04x\n", 525 dev_id, base_addr); 526 527exit: 528 sch311x_sio_exit(sio_config_port); 529 return err; 530} 531 532static int __init sch311x_wdt_init(void) 533{ 534 int err, i, found = 0; 535 unsigned short addr = 0; 536 537 for (i = 0; !found && sch311x_ioports[i]; i++) 538 if (sch311x_detect(sch311x_ioports[i], &addr) == 0) 539 found++; 540 541 if (!found) 542 return -ENODEV; 543 544 sch311x_wdt_data.runtime_reg = addr; 545 546 err = platform_driver_register(&sch311x_wdt_driver); 547 if (err) 548 return err; 549 550 sch311x_wdt_pdev = platform_device_register_simple(DRV_NAME, addr, 551 NULL, 0); 552 553 if (IS_ERR(sch311x_wdt_pdev)) { 554 err = PTR_ERR(sch311x_wdt_pdev); 555 goto unreg_platform_driver; 556 } 557 558 return 0; 559 560unreg_platform_driver: 561 platform_driver_unregister(&sch311x_wdt_driver); 562 return err; 563} 564 565static void __exit sch311x_wdt_exit(void) 566{ 567 platform_device_unregister(sch311x_wdt_pdev); 568 platform_driver_unregister(&sch311x_wdt_driver); 569} 570 571module_init(sch311x_wdt_init); 572module_exit(sch311x_wdt_exit); 573 574MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>"); 575MODULE_DESCRIPTION("SMSC SCH311x WatchDog Timer Driver"); 576MODULE_LICENSE("GPL"); 577MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 578