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 struct miscdevice */ 30 #include <linux/watchdog.h> /* For the watchdog specific items */ 31 #include <linux/init.h> /* For __init/__exit/... */ 32 #include <linux/fs.h> /* For file operations */ 33 #include <linux/platform_device.h> /* For platform_driver framework */ 34 #include <linux/ioport.h> /* For io-port access */ 35 #include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */ 36 #include <linux/uaccess.h> /* For copy_to_user/put_user/... */ 37 #include <linux/io.h> /* For inb/outb/... */ 38 39 /* Module and version information */ 40 #define DRV_NAME "sch311x_wdt" 41 42 /* Runtime registers */ 43 #define GP60 0x47 44 #define WDT_TIME_OUT 0x65 45 #define WDT_VAL 0x66 46 #define WDT_CFG 0x67 47 #define WDT_CTRL 0x68 48 49 /* internal variables */ 50 static unsigned long sch311x_wdt_is_open; 51 static char sch311x_wdt_expect_close; 52 static struct platform_device *sch311x_wdt_pdev; 53 54 static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e, 0x00 }; 55 56 static struct { /* The devices private data */ 57 /* the Runtime Register base address */ 58 unsigned short runtime_reg; 59 /* The card's boot status */ 60 int boot_status; 61 /* the lock for io operations */ 62 spinlock_t io_lock; 63 } sch311x_wdt_data; 64 65 /* Module load parameters */ 66 static unsigned short force_id; 67 module_param(force_id, ushort, 0); 68 MODULE_PARM_DESC(force_id, "Override the detected device ID"); 69 70 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ 71 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ 72 module_param(timeout, int, 0); 73 MODULE_PARM_DESC(timeout, 74 "Watchdog timeout in seconds. 1<= timeout <=15300, default=" 75 __MODULE_STRING(WATCHDOG_TIMEOUT) "."); 76 77 static bool nowayout = WATCHDOG_NOWAYOUT; 78 module_param(nowayout, bool, 0); 79 MODULE_PARM_DESC(nowayout, 80 "Watchdog cannot be stopped once started (default=" 81 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 82 83 /* 84 * Super-IO functions 85 */ 86 87 static inline void sch311x_sio_enter(int sio_config_port) 88 { 89 outb(0x55, sio_config_port); 90 } 91 92 static inline void sch311x_sio_exit(int sio_config_port) 93 { 94 outb(0xaa, sio_config_port); 95 } 96 97 static inline int sch311x_sio_inb(int sio_config_port, int reg) 98 { 99 outb(reg, sio_config_port); 100 return inb(sio_config_port + 1); 101 } 102 103 static inline void sch311x_sio_outb(int sio_config_port, int reg, int val) 104 { 105 outb(reg, sio_config_port); 106 outb(val, sio_config_port + 1); 107 } 108 109 /* 110 * Watchdog Operations 111 */ 112 113 static void sch311x_wdt_set_timeout(int t) 114 { 115 unsigned char timeout_unit = 0x80; 116 117 /* When new timeout is bigger then 255 seconds, we will use minutes */ 118 if (t > 255) { 119 timeout_unit = 0; 120 t /= 60; 121 } 122 123 /* -- Watchdog Timeout -- 124 * Bit 0-6 (Reserved) 125 * Bit 7 WDT Time-out Value Units Select 126 * (0 = Minutes, 1 = Seconds) 127 */ 128 outb(timeout_unit, sch311x_wdt_data.runtime_reg + WDT_TIME_OUT); 129 130 /* -- Watchdog Timer Time-out Value -- 131 * Bit 0-7 Binary coded units (0=Disabled, 1..255) 132 */ 133 outb(t, sch311x_wdt_data.runtime_reg + WDT_VAL); 134 } 135 136 static void sch311x_wdt_start(void) 137 { 138 unsigned char t; 139 140 spin_lock(&sch311x_wdt_data.io_lock); 141 142 /* set watchdog's timeout */ 143 sch311x_wdt_set_timeout(timeout); 144 /* enable the watchdog */ 145 /* -- General Purpose I/O Bit 6.0 -- 146 * Bit 0, In/Out: 0 = Output, 1 = Input 147 * Bit 1, Polarity: 0 = No Invert, 1 = Invert 148 * Bit 2-3, Function select: 00 = GPI/O, 01 = LED1, 11 = WDT, 149 * 10 = Either Edge Triggered Intr.4 150 * Bit 4-6 (Reserved) 151 * Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain 152 */ 153 t = inb(sch311x_wdt_data.runtime_reg + GP60); 154 outb((t & ~0x0d) | 0x0c, sch311x_wdt_data.runtime_reg + GP60); 155 156 spin_unlock(&sch311x_wdt_data.io_lock); 157 158 } 159 160 static void sch311x_wdt_stop(void) 161 { 162 unsigned char t; 163 164 spin_lock(&sch311x_wdt_data.io_lock); 165 166 /* stop the watchdog */ 167 t = inb(sch311x_wdt_data.runtime_reg + GP60); 168 outb((t & ~0x0d) | 0x01, sch311x_wdt_data.runtime_reg + GP60); 169 /* disable timeout by setting it to 0 */ 170 sch311x_wdt_set_timeout(0); 171 172 spin_unlock(&sch311x_wdt_data.io_lock); 173 } 174 175 static void sch311x_wdt_keepalive(void) 176 { 177 spin_lock(&sch311x_wdt_data.io_lock); 178 sch311x_wdt_set_timeout(timeout); 179 spin_unlock(&sch311x_wdt_data.io_lock); 180 } 181 182 static int sch311x_wdt_set_heartbeat(int t) 183 { 184 if (t < 1 || t > (255*60)) 185 return -EINVAL; 186 187 /* When new timeout is bigger then 255 seconds, 188 * we will round up to minutes (with a max of 255) */ 189 if (t > 255) 190 t = (((t - 1) / 60) + 1) * 60; 191 192 timeout = t; 193 return 0; 194 } 195 196 static void sch311x_wdt_get_status(int *status) 197 { 198 unsigned char new_status; 199 200 *status = 0; 201 202 spin_lock(&sch311x_wdt_data.io_lock); 203 204 /* -- Watchdog timer control -- 205 * Bit 0 Status Bit: 0 = Timer counting, 1 = Timeout occurred 206 * Bit 1 Reserved 207 * Bit 2 Force Timeout: 1 = Forces WD timeout event (self-cleaning) 208 * Bit 3 P20 Force Timeout enabled: 209 * 0 = P20 activity does not generate the WD timeout event 210 * 1 = P20 Allows rising edge of P20, from the keyboard 211 * controller, to force the WD timeout event. 212 * Bit 4-7 Reserved 213 */ 214 new_status = inb(sch311x_wdt_data.runtime_reg + WDT_CTRL); 215 if (new_status & 0x01) 216 *status |= WDIOF_CARDRESET; 217 218 spin_unlock(&sch311x_wdt_data.io_lock); 219 } 220 221 /* 222 * /dev/watchdog handling 223 */ 224 225 static ssize_t sch311x_wdt_write(struct file *file, const char __user *buf, 226 size_t count, loff_t *ppos) 227 { 228 if (count) { 229 if (!nowayout) { 230 size_t i; 231 232 sch311x_wdt_expect_close = 0; 233 234 for (i = 0; i != count; i++) { 235 char c; 236 if (get_user(c, buf + i)) 237 return -EFAULT; 238 if (c == 'V') 239 sch311x_wdt_expect_close = 42; 240 } 241 } 242 sch311x_wdt_keepalive(); 243 } 244 return count; 245 } 246 247 static long sch311x_wdt_ioctl(struct file *file, unsigned int cmd, 248 unsigned long arg) 249 { 250 int status; 251 int new_timeout; 252 void __user *argp = (void __user *)arg; 253 int __user *p = argp; 254 static const struct watchdog_info ident = { 255 .options = WDIOF_KEEPALIVEPING | 256 WDIOF_SETTIMEOUT | 257 WDIOF_MAGICCLOSE, 258 .firmware_version = 1, 259 .identity = DRV_NAME, 260 }; 261 262 switch (cmd) { 263 case WDIOC_GETSUPPORT: 264 if (copy_to_user(argp, &ident, sizeof(ident))) 265 return -EFAULT; 266 break; 267 268 case WDIOC_GETSTATUS: 269 { 270 sch311x_wdt_get_status(&status); 271 return put_user(status, p); 272 } 273 case WDIOC_GETBOOTSTATUS: 274 return put_user(sch311x_wdt_data.boot_status, p); 275 276 case WDIOC_SETOPTIONS: 277 { 278 int options, retval = -EINVAL; 279 280 if (get_user(options, p)) 281 return -EFAULT; 282 if (options & WDIOS_DISABLECARD) { 283 sch311x_wdt_stop(); 284 retval = 0; 285 } 286 if (options & WDIOS_ENABLECARD) { 287 sch311x_wdt_start(); 288 retval = 0; 289 } 290 return retval; 291 } 292 case WDIOC_KEEPALIVE: 293 sch311x_wdt_keepalive(); 294 break; 295 296 case WDIOC_SETTIMEOUT: 297 if (get_user(new_timeout, p)) 298 return -EFAULT; 299 if (sch311x_wdt_set_heartbeat(new_timeout)) 300 return -EINVAL; 301 sch311x_wdt_keepalive(); 302 /* Fall */ 303 case WDIOC_GETTIMEOUT: 304 return put_user(timeout, p); 305 default: 306 return -ENOTTY; 307 } 308 return 0; 309 } 310 311 static int sch311x_wdt_open(struct inode *inode, struct file *file) 312 { 313 if (test_and_set_bit(0, &sch311x_wdt_is_open)) 314 return -EBUSY; 315 /* 316 * Activate 317 */ 318 sch311x_wdt_start(); 319 return nonseekable_open(inode, file); 320 } 321 322 static int sch311x_wdt_close(struct inode *inode, struct file *file) 323 { 324 if (sch311x_wdt_expect_close == 42) { 325 sch311x_wdt_stop(); 326 } else { 327 pr_crit("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 */ 338 339 static 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 }; 347 348 static 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 */ 357 358 static int sch311x_wdt_probe(struct platform_device *pdev) 359 { 360 struct device *dev = &pdev->dev; 361 int err; 362 363 spin_lock_init(&sch311x_wdt_data.io_lock); 364 365 if (!request_region(sch311x_wdt_data.runtime_reg + GP60, 1, DRV_NAME)) { 366 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n", 367 sch311x_wdt_data.runtime_reg + GP60, 368 sch311x_wdt_data.runtime_reg + GP60); 369 err = -EBUSY; 370 goto exit; 371 } 372 373 if (!request_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4, 374 DRV_NAME)) { 375 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n", 376 sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 377 sch311x_wdt_data.runtime_reg + WDT_CTRL); 378 err = -EBUSY; 379 goto exit_release_region; 380 } 381 382 /* Make sure that the watchdog is not running */ 383 sch311x_wdt_stop(); 384 385 /* Disable keyboard and mouse interaction and interrupt */ 386 /* -- Watchdog timer configuration -- 387 * Bit 0 Reserved 388 * Bit 1 Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr. 389 * Bit 2 Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr 390 * Bit 3 Reserved 391 * Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled, 392 * 0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15) 393 */ 394 outb(0, sch311x_wdt_data.runtime_reg + WDT_CFG); 395 396 /* Check that the heartbeat value is within it's range ; 397 * if not reset to the default */ 398 if (sch311x_wdt_set_heartbeat(timeout)) { 399 sch311x_wdt_set_heartbeat(WATCHDOG_TIMEOUT); 400 dev_info(dev, "timeout value must be 1<=x<=15300, using %d\n", 401 timeout); 402 } 403 404 /* Get status at boot */ 405 sch311x_wdt_get_status(&sch311x_wdt_data.boot_status); 406 407 sch311x_wdt_miscdev.parent = dev; 408 409 err = misc_register(&sch311x_wdt_miscdev); 410 if (err != 0) { 411 dev_err(dev, "cannot register miscdev on minor=%d (err=%d)\n", 412 WATCHDOG_MINOR, err); 413 goto exit_release_region2; 414 } 415 416 dev_info(dev, 417 "SMSC SCH311x WDT initialized. timeout=%d sec (nowayout=%d)\n", 418 timeout, nowayout); 419 420 return 0; 421 422 exit_release_region2: 423 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4); 424 exit_release_region: 425 release_region(sch311x_wdt_data.runtime_reg + GP60, 1); 426 sch311x_wdt_data.runtime_reg = 0; 427 exit: 428 return err; 429 } 430 431 static int sch311x_wdt_remove(struct platform_device *pdev) 432 { 433 /* Stop the timer before we leave */ 434 if (!nowayout) 435 sch311x_wdt_stop(); 436 437 /* Deregister */ 438 misc_deregister(&sch311x_wdt_miscdev); 439 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4); 440 release_region(sch311x_wdt_data.runtime_reg + GP60, 1); 441 sch311x_wdt_data.runtime_reg = 0; 442 return 0; 443 } 444 445 static void sch311x_wdt_shutdown(struct platform_device *dev) 446 { 447 /* Turn the WDT off if we have a soft shutdown */ 448 sch311x_wdt_stop(); 449 } 450 451 static struct platform_driver sch311x_wdt_driver = { 452 .probe = sch311x_wdt_probe, 453 .remove = sch311x_wdt_remove, 454 .shutdown = sch311x_wdt_shutdown, 455 .driver = { 456 .name = DRV_NAME, 457 }, 458 }; 459 460 static int __init sch311x_detect(int sio_config_port, unsigned short *addr) 461 { 462 int err = 0, reg; 463 unsigned short base_addr; 464 unsigned char dev_id; 465 466 sch311x_sio_enter(sio_config_port); 467 468 /* Check device ID. We currently know about: 469 * SCH3112 (0x7c), SCH3114 (0x7d), and SCH3116 (0x7f). */ 470 reg = force_id ? force_id : sch311x_sio_inb(sio_config_port, 0x20); 471 if (!(reg == 0x7c || reg == 0x7d || reg == 0x7f)) { 472 err = -ENODEV; 473 goto exit; 474 } 475 dev_id = reg == 0x7c ? 2 : reg == 0x7d ? 4 : 6; 476 477 /* Select logical device A (runtime registers) */ 478 sch311x_sio_outb(sio_config_port, 0x07, 0x0a); 479 480 /* Check if Logical Device Register is currently active */ 481 if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0) 482 pr_info("Seems that LDN 0x0a is not active...\n"); 483 484 /* Get the base address of the runtime registers */ 485 base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) | 486 sch311x_sio_inb(sio_config_port, 0x61); 487 if (!base_addr) { 488 pr_err("Base address not set\n"); 489 err = -ENODEV; 490 goto exit; 491 } 492 *addr = base_addr; 493 494 pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr); 495 496 exit: 497 sch311x_sio_exit(sio_config_port); 498 return err; 499 } 500 501 static int __init sch311x_wdt_init(void) 502 { 503 int err, i, found = 0; 504 unsigned short addr = 0; 505 506 for (i = 0; !found && sch311x_ioports[i]; i++) 507 if (sch311x_detect(sch311x_ioports[i], &addr) == 0) 508 found++; 509 510 if (!found) 511 return -ENODEV; 512 513 sch311x_wdt_data.runtime_reg = addr; 514 515 err = platform_driver_register(&sch311x_wdt_driver); 516 if (err) 517 return err; 518 519 sch311x_wdt_pdev = platform_device_register_simple(DRV_NAME, addr, 520 NULL, 0); 521 522 if (IS_ERR(sch311x_wdt_pdev)) { 523 err = PTR_ERR(sch311x_wdt_pdev); 524 goto unreg_platform_driver; 525 } 526 527 return 0; 528 529 unreg_platform_driver: 530 platform_driver_unregister(&sch311x_wdt_driver); 531 return err; 532 } 533 534 static void __exit sch311x_wdt_exit(void) 535 { 536 platform_device_unregister(sch311x_wdt_pdev); 537 platform_driver_unregister(&sch311x_wdt_driver); 538 } 539 540 module_init(sch311x_wdt_init); 541 module_exit(sch311x_wdt_exit); 542 543 MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>"); 544 MODULE_DESCRIPTION("SMSC SCH311x WatchDog Timer Driver"); 545 MODULE_LICENSE("GPL"); 546