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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 22 23 /* Includes */ 24 #include <linux/module.h> /* For module specific items */ 25 #include <linux/moduleparam.h> /* For new moduleparam's */ 26 #include <linux/types.h> /* For standard types (like size_t) */ 27 #include <linux/errno.h> /* For the -ENODEV/... values */ 28 #include <linux/kernel.h> /* For printk/... */ 29 #include <linux/miscdevice.h> /* For MODULE_ALIAS_MISCDEV 30 (WATCHDOG_MINOR) */ 31 #include <linux/watchdog.h> /* For the watchdog specific items */ 32 #include <linux/init.h> /* For __init/__exit/... */ 33 #include <linux/fs.h> /* For file operations */ 34 #include <linux/platform_device.h> /* For platform_driver framework */ 35 #include <linux/ioport.h> /* For io-port access */ 36 #include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */ 37 #include <linux/uaccess.h> /* For copy_to_user/put_user/... */ 38 #include <linux/io.h> /* For inb/outb/... */ 39 40 /* Module and version information */ 41 #define DRV_NAME "sch311x_wdt" 42 43 /* Runtime registers */ 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 */ 51 static unsigned long sch311x_wdt_is_open; 52 static char sch311x_wdt_expect_close; 53 static struct platform_device *sch311x_wdt_pdev; 54 55 static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e, 0x00 }; 56 57 static 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 */ 67 static unsigned short force_id; 68 module_param(force_id, ushort, 0); 69 MODULE_PARM_DESC(force_id, "Override the detected device ID"); 70 71 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ 72 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ 73 module_param(timeout, int, 0); 74 MODULE_PARM_DESC(timeout, 75 "Watchdog timeout in seconds. 1<= timeout <=15300, default=" 76 __MODULE_STRING(WATCHDOG_TIMEOUT) "."); 77 78 static bool nowayout = WATCHDOG_NOWAYOUT; 79 module_param(nowayout, bool, 0); 80 MODULE_PARM_DESC(nowayout, 81 "Watchdog cannot be stopped once started (default=" 82 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 83 84 /* 85 * Super-IO functions 86 */ 87 88 static inline void sch311x_sio_enter(int sio_config_port) 89 { 90 outb(0x55, sio_config_port); 91 } 92 93 static inline void sch311x_sio_exit(int sio_config_port) 94 { 95 outb(0xaa, sio_config_port); 96 } 97 98 static inline int sch311x_sio_inb(int sio_config_port, int reg) 99 { 100 outb(reg, sio_config_port); 101 return inb(sio_config_port + 1); 102 } 103 104 static inline void sch311x_sio_outb(int sio_config_port, int reg, int val) 105 { 106 outb(reg, sio_config_port); 107 outb(val, sio_config_port + 1); 108 } 109 110 /* 111 * Watchdog Operations 112 */ 113 114 static void sch311x_wdt_set_timeout(int t) 115 { 116 unsigned char timeout_unit = 0x80; 117 118 /* When new timeout is bigger then 255 seconds, we will use minutes */ 119 if (t > 255) { 120 timeout_unit = 0; 121 t /= 60; 122 } 123 124 /* -- Watchdog Timeout -- 125 * Bit 0-6 (Reserved) 126 * Bit 7 WDT Time-out Value Units Select 127 * (0 = Minutes, 1 = Seconds) 128 */ 129 outb(timeout_unit, sch311x_wdt_data.runtime_reg + WDT_TIME_OUT); 130 131 /* -- Watchdog Timer Time-out Value -- 132 * Bit 0-7 Binary coded units (0=Disabled, 1..255) 133 */ 134 outb(t, sch311x_wdt_data.runtime_reg + WDT_VAL); 135 } 136 137 static void sch311x_wdt_start(void) 138 { 139 unsigned char t; 140 141 spin_lock(&sch311x_wdt_data.io_lock); 142 143 /* set watchdog's timeout */ 144 sch311x_wdt_set_timeout(timeout); 145 /* enable the watchdog */ 146 /* -- General Purpose I/O Bit 6.0 -- 147 * Bit 0, In/Out: 0 = Output, 1 = Input 148 * Bit 1, Polarity: 0 = No Invert, 1 = Invert 149 * Bit 2-3, Function select: 00 = GPI/O, 01 = LED1, 11 = WDT, 150 * 10 = Either Edge Triggered Intr.4 151 * Bit 4-6 (Reserved) 152 * Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain 153 */ 154 t = inb(sch311x_wdt_data.runtime_reg + GP60); 155 outb((t & ~0x0d) | 0x0c, sch311x_wdt_data.runtime_reg + GP60); 156 157 spin_unlock(&sch311x_wdt_data.io_lock); 158 159 } 160 161 static void sch311x_wdt_stop(void) 162 { 163 unsigned char t; 164 165 spin_lock(&sch311x_wdt_data.io_lock); 166 167 /* stop the watchdog */ 168 t = inb(sch311x_wdt_data.runtime_reg + GP60); 169 outb((t & ~0x0d) | 0x01, sch311x_wdt_data.runtime_reg + GP60); 170 /* disable timeout by setting it to 0 */ 171 sch311x_wdt_set_timeout(0); 172 173 spin_unlock(&sch311x_wdt_data.io_lock); 174 } 175 176 static void sch311x_wdt_keepalive(void) 177 { 178 spin_lock(&sch311x_wdt_data.io_lock); 179 sch311x_wdt_set_timeout(timeout); 180 spin_unlock(&sch311x_wdt_data.io_lock); 181 } 182 183 static int sch311x_wdt_set_heartbeat(int t) 184 { 185 if (t < 1 || t > (255*60)) 186 return -EINVAL; 187 188 /* When new timeout is bigger then 255 seconds, 189 * we will round up to minutes (with a max of 255) */ 190 if (t > 255) 191 t = (((t - 1) / 60) + 1) * 60; 192 193 timeout = t; 194 return 0; 195 } 196 197 static void sch311x_wdt_get_status(int *status) 198 { 199 unsigned char new_status; 200 201 *status = 0; 202 203 spin_lock(&sch311x_wdt_data.io_lock); 204 205 /* -- Watchdog timer control -- 206 * Bit 0 Status Bit: 0 = Timer counting, 1 = Timeout occurred 207 * Bit 1 Reserved 208 * Bit 2 Force Timeout: 1 = Forces WD timeout event (self-cleaning) 209 * Bit 3 P20 Force Timeout enabled: 210 * 0 = P20 activity does not generate the WD timeout event 211 * 1 = P20 Allows rising edge of P20, from the keyboard 212 * controller, to force the WD timeout event. 213 * Bit 4-7 Reserved 214 */ 215 new_status = inb(sch311x_wdt_data.runtime_reg + WDT_CTRL); 216 if (new_status & 0x01) 217 *status |= WDIOF_CARDRESET; 218 219 spin_unlock(&sch311x_wdt_data.io_lock); 220 } 221 222 /* 223 * /dev/watchdog handling 224 */ 225 226 static ssize_t sch311x_wdt_write(struct file *file, const char __user *buf, 227 size_t count, loff_t *ppos) 228 { 229 if (count) { 230 if (!nowayout) { 231 size_t i; 232 233 sch311x_wdt_expect_close = 0; 234 235 for (i = 0; i != count; i++) { 236 char c; 237 if (get_user(c, buf + i)) 238 return -EFAULT; 239 if (c == 'V') 240 sch311x_wdt_expect_close = 42; 241 } 242 } 243 sch311x_wdt_keepalive(); 244 } 245 return count; 246 } 247 248 static long sch311x_wdt_ioctl(struct file *file, unsigned int cmd, 249 unsigned long arg) 250 { 251 int status; 252 int new_timeout; 253 void __user *argp = (void __user *)arg; 254 int __user *p = argp; 255 static const struct watchdog_info ident = { 256 .options = WDIOF_KEEPALIVEPING | 257 WDIOF_SETTIMEOUT | 258 WDIOF_MAGICCLOSE, 259 .firmware_version = 1, 260 .identity = DRV_NAME, 261 }; 262 263 switch (cmd) { 264 case WDIOC_GETSUPPORT: 265 if (copy_to_user(argp, &ident, sizeof(ident))) 266 return -EFAULT; 267 break; 268 269 case WDIOC_GETSTATUS: 270 { 271 sch311x_wdt_get_status(&status); 272 return put_user(status, p); 273 } 274 case WDIOC_GETBOOTSTATUS: 275 return put_user(sch311x_wdt_data.boot_status, p); 276 277 case WDIOC_SETOPTIONS: 278 { 279 int options, retval = -EINVAL; 280 281 if (get_user(options, p)) 282 return -EFAULT; 283 if (options & WDIOS_DISABLECARD) { 284 sch311x_wdt_stop(); 285 retval = 0; 286 } 287 if (options & WDIOS_ENABLECARD) { 288 sch311x_wdt_start(); 289 retval = 0; 290 } 291 return retval; 292 } 293 case WDIOC_KEEPALIVE: 294 sch311x_wdt_keepalive(); 295 break; 296 297 case WDIOC_SETTIMEOUT: 298 if (get_user(new_timeout, p)) 299 return -EFAULT; 300 if (sch311x_wdt_set_heartbeat(new_timeout)) 301 return -EINVAL; 302 sch311x_wdt_keepalive(); 303 /* Fall */ 304 case WDIOC_GETTIMEOUT: 305 return put_user(timeout, p); 306 default: 307 return -ENOTTY; 308 } 309 return 0; 310 } 311 312 static int sch311x_wdt_open(struct inode *inode, struct file *file) 313 { 314 if (test_and_set_bit(0, &sch311x_wdt_is_open)) 315 return -EBUSY; 316 /* 317 * Activate 318 */ 319 sch311x_wdt_start(); 320 return nonseekable_open(inode, file); 321 } 322 323 static int sch311x_wdt_close(struct inode *inode, struct file *file) 324 { 325 if (sch311x_wdt_expect_close == 42) { 326 sch311x_wdt_stop(); 327 } else { 328 pr_crit("Unexpected close, not stopping watchdog!\n"); 329 sch311x_wdt_keepalive(); 330 } 331 clear_bit(0, &sch311x_wdt_is_open); 332 sch311x_wdt_expect_close = 0; 333 return 0; 334 } 335 336 /* 337 * Kernel Interfaces 338 */ 339 340 static const struct file_operations sch311x_wdt_fops = { 341 .owner = THIS_MODULE, 342 .llseek = no_llseek, 343 .write = sch311x_wdt_write, 344 .unlocked_ioctl = sch311x_wdt_ioctl, 345 .open = sch311x_wdt_open, 346 .release = sch311x_wdt_close, 347 }; 348 349 static struct miscdevice sch311x_wdt_miscdev = { 350 .minor = WATCHDOG_MINOR, 351 .name = "watchdog", 352 .fops = &sch311x_wdt_fops, 353 }; 354 355 /* 356 * Init & exit routines 357 */ 358 359 static int sch311x_wdt_probe(struct platform_device *pdev) 360 { 361 struct device *dev = &pdev->dev; 362 int err; 363 364 spin_lock_init(&sch311x_wdt_data.io_lock); 365 366 if (!request_region(sch311x_wdt_data.runtime_reg + GP60, 1, DRV_NAME)) { 367 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n", 368 sch311x_wdt_data.runtime_reg + GP60, 369 sch311x_wdt_data.runtime_reg + GP60); 370 err = -EBUSY; 371 goto exit; 372 } 373 374 if (!request_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4, 375 DRV_NAME)) { 376 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n", 377 sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 378 sch311x_wdt_data.runtime_reg + WDT_CTRL); 379 err = -EBUSY; 380 goto exit_release_region; 381 } 382 383 /* Make sure that the watchdog is not running */ 384 sch311x_wdt_stop(); 385 386 /* Disable keyboard and mouse interaction and interrupt */ 387 /* -- Watchdog timer configuration -- 388 * Bit 0 Reserved 389 * Bit 1 Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr. 390 * Bit 2 Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr 391 * Bit 3 Reserved 392 * Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled, 393 * 0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15) 394 */ 395 outb(0, sch311x_wdt_data.runtime_reg + WDT_CFG); 396 397 /* Check that the heartbeat value is within it's range ; 398 * if not reset to the default */ 399 if (sch311x_wdt_set_heartbeat(timeout)) { 400 sch311x_wdt_set_heartbeat(WATCHDOG_TIMEOUT); 401 dev_info(dev, "timeout value must be 1<=x<=15300, using %d\n", 402 timeout); 403 } 404 405 /* Get status at boot */ 406 sch311x_wdt_get_status(&sch311x_wdt_data.boot_status); 407 408 sch311x_wdt_miscdev.parent = dev; 409 410 err = misc_register(&sch311x_wdt_miscdev); 411 if (err != 0) { 412 dev_err(dev, "cannot register miscdev on minor=%d (err=%d)\n", 413 WATCHDOG_MINOR, err); 414 goto exit_release_region2; 415 } 416 417 dev_info(dev, 418 "SMSC SCH311x WDT initialized. timeout=%d sec (nowayout=%d)\n", 419 timeout, nowayout); 420 421 return 0; 422 423 exit_release_region2: 424 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4); 425 exit_release_region: 426 release_region(sch311x_wdt_data.runtime_reg + GP60, 1); 427 sch311x_wdt_data.runtime_reg = 0; 428 exit: 429 return err; 430 } 431 432 static int sch311x_wdt_remove(struct platform_device *pdev) 433 { 434 /* Stop the timer before we leave */ 435 if (!nowayout) 436 sch311x_wdt_stop(); 437 438 /* Deregister */ 439 misc_deregister(&sch311x_wdt_miscdev); 440 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4); 441 release_region(sch311x_wdt_data.runtime_reg + GP60, 1); 442 sch311x_wdt_data.runtime_reg = 0; 443 return 0; 444 } 445 446 static void sch311x_wdt_shutdown(struct platform_device *dev) 447 { 448 /* Turn the WDT off if we have a soft shutdown */ 449 sch311x_wdt_stop(); 450 } 451 452 static struct platform_driver sch311x_wdt_driver = { 453 .probe = sch311x_wdt_probe, 454 .remove = sch311x_wdt_remove, 455 .shutdown = sch311x_wdt_shutdown, 456 .driver = { 457 .owner = THIS_MODULE, 458 .name = DRV_NAME, 459 }, 460 }; 461 462 static int __init sch311x_detect(int sio_config_port, unsigned short *addr) 463 { 464 int err = 0, reg; 465 unsigned short base_addr; 466 unsigned char dev_id; 467 468 sch311x_sio_enter(sio_config_port); 469 470 /* Check device ID. We currently know about: 471 * SCH3112 (0x7c), SCH3114 (0x7d), and SCH3116 (0x7f). */ 472 reg = force_id ? force_id : sch311x_sio_inb(sio_config_port, 0x20); 473 if (!(reg == 0x7c || reg == 0x7d || reg == 0x7f)) { 474 err = -ENODEV; 475 goto exit; 476 } 477 dev_id = reg == 0x7c ? 2 : reg == 0x7d ? 4 : 6; 478 479 /* Select logical device A (runtime registers) */ 480 sch311x_sio_outb(sio_config_port, 0x07, 0x0a); 481 482 /* Check if Logical Device Register is currently active */ 483 if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0) 484 pr_info("Seems that LDN 0x0a is not active...\n"); 485 486 /* Get the base address of the runtime registers */ 487 base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) | 488 sch311x_sio_inb(sio_config_port, 0x61); 489 if (!base_addr) { 490 pr_err("Base address not set\n"); 491 err = -ENODEV; 492 goto exit; 493 } 494 *addr = base_addr; 495 496 pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr); 497 498 exit: 499 sch311x_sio_exit(sio_config_port); 500 return err; 501 } 502 503 static int __init sch311x_wdt_init(void) 504 { 505 int err, i, found = 0; 506 unsigned short addr = 0; 507 508 for (i = 0; !found && sch311x_ioports[i]; i++) 509 if (sch311x_detect(sch311x_ioports[i], &addr) == 0) 510 found++; 511 512 if (!found) 513 return -ENODEV; 514 515 sch311x_wdt_data.runtime_reg = addr; 516 517 err = platform_driver_register(&sch311x_wdt_driver); 518 if (err) 519 return err; 520 521 sch311x_wdt_pdev = platform_device_register_simple(DRV_NAME, addr, 522 NULL, 0); 523 524 if (IS_ERR(sch311x_wdt_pdev)) { 525 err = PTR_ERR(sch311x_wdt_pdev); 526 goto unreg_platform_driver; 527 } 528 529 return 0; 530 531 unreg_platform_driver: 532 platform_driver_unregister(&sch311x_wdt_driver); 533 return err; 534 } 535 536 static void __exit sch311x_wdt_exit(void) 537 { 538 platform_device_unregister(sch311x_wdt_pdev); 539 platform_driver_unregister(&sch311x_wdt_driver); 540 } 541 542 module_init(sch311x_wdt_init); 543 module_exit(sch311x_wdt_exit); 544 545 MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>"); 546 MODULE_DESCRIPTION("SMSC SCH311x WatchDog Timer Driver"); 547 MODULE_LICENSE("GPL"); 548 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 549 550