1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * sch311x_wdt.c - Driver for the SCH311x Super-I/O chips 4 * integrated watchdog. 5 * 6 * (c) Copyright 2008 Wim Van Sebroeck <wim@iguana.be>. 7 * 8 * Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor 9 * provide warranty for any of this software. This material is 10 * provided "AS-IS" and at no charge. 11 */ 12 13 /* 14 * Includes, defines, variables, module parameters, ... 15 */ 16 17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 18 19 /* Includes */ 20 #include <linux/module.h> /* For module specific items */ 21 #include <linux/moduleparam.h> /* For new moduleparam's */ 22 #include <linux/types.h> /* For standard types (like size_t) */ 23 #include <linux/errno.h> /* For the -ENODEV/... values */ 24 #include <linux/kernel.h> /* For printk/... */ 25 #include <linux/miscdevice.h> /* For struct miscdevice */ 26 #include <linux/watchdog.h> /* For the watchdog specific items */ 27 #include <linux/init.h> /* For __init/__exit/... */ 28 #include <linux/fs.h> /* For file operations */ 29 #include <linux/platform_device.h> /* For platform_driver framework */ 30 #include <linux/ioport.h> /* For io-port access */ 31 #include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */ 32 #include <linux/uaccess.h> /* For copy_to_user/put_user/... */ 33 #include <linux/io.h> /* For inb/outb/... */ 34 35 /* Module and version information */ 36 #define DRV_NAME "sch311x_wdt" 37 38 /* Runtime registers */ 39 #define GP60 0x47 40 #define WDT_TIME_OUT 0x65 41 #define WDT_VAL 0x66 42 #define WDT_CFG 0x67 43 #define WDT_CTRL 0x68 44 45 /* internal variables */ 46 static unsigned long sch311x_wdt_is_open; 47 static char sch311x_wdt_expect_close; 48 static struct platform_device *sch311x_wdt_pdev; 49 50 static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e, 0x00 }; 51 52 static struct { /* The devices private data */ 53 /* the Runtime Register base address */ 54 unsigned short runtime_reg; 55 /* The card's boot status */ 56 int boot_status; 57 /* the lock for io operations */ 58 spinlock_t io_lock; 59 } sch311x_wdt_data; 60 61 /* Module load parameters */ 62 static unsigned short force_id; 63 module_param(force_id, ushort, 0); 64 MODULE_PARM_DESC(force_id, "Override the detected device ID"); 65 66 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ 67 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ 68 module_param(timeout, int, 0); 69 MODULE_PARM_DESC(timeout, 70 "Watchdog timeout in seconds. 1<= timeout <=15300, default=" 71 __MODULE_STRING(WATCHDOG_TIMEOUT) "."); 72 73 static bool nowayout = WATCHDOG_NOWAYOUT; 74 module_param(nowayout, bool, 0); 75 MODULE_PARM_DESC(nowayout, 76 "Watchdog cannot be stopped once started (default=" 77 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 78 79 /* 80 * Super-IO functions 81 */ 82 83 static inline void sch311x_sio_enter(int sio_config_port) 84 { 85 outb(0x55, sio_config_port); 86 } 87 88 static inline void sch311x_sio_exit(int sio_config_port) 89 { 90 outb(0xaa, sio_config_port); 91 } 92 93 static inline int sch311x_sio_inb(int sio_config_port, int reg) 94 { 95 outb(reg, sio_config_port); 96 return inb(sio_config_port + 1); 97 } 98 99 static inline void sch311x_sio_outb(int sio_config_port, int reg, int val) 100 { 101 outb(reg, sio_config_port); 102 outb(val, sio_config_port + 1); 103 } 104 105 /* 106 * Watchdog Operations 107 */ 108 109 static void sch311x_wdt_set_timeout(int t) 110 { 111 unsigned char timeout_unit = 0x80; 112 113 /* When new timeout is bigger then 255 seconds, we will use minutes */ 114 if (t > 255) { 115 timeout_unit = 0; 116 t /= 60; 117 } 118 119 /* -- Watchdog Timeout -- 120 * Bit 0-6 (Reserved) 121 * Bit 7 WDT Time-out Value Units Select 122 * (0 = Minutes, 1 = Seconds) 123 */ 124 outb(timeout_unit, sch311x_wdt_data.runtime_reg + WDT_TIME_OUT); 125 126 /* -- Watchdog Timer Time-out Value -- 127 * Bit 0-7 Binary coded units (0=Disabled, 1..255) 128 */ 129 outb(t, sch311x_wdt_data.runtime_reg + WDT_VAL); 130 } 131 132 static void sch311x_wdt_start(void) 133 { 134 unsigned char t; 135 136 spin_lock(&sch311x_wdt_data.io_lock); 137 138 /* set watchdog's timeout */ 139 sch311x_wdt_set_timeout(timeout); 140 /* enable the watchdog */ 141 /* -- General Purpose I/O Bit 6.0 -- 142 * Bit 0, In/Out: 0 = Output, 1 = Input 143 * Bit 1, Polarity: 0 = No Invert, 1 = Invert 144 * Bit 2-3, Function select: 00 = GPI/O, 01 = LED1, 11 = WDT, 145 * 10 = Either Edge Triggered Intr.4 146 * Bit 4-6 (Reserved) 147 * Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain 148 */ 149 t = inb(sch311x_wdt_data.runtime_reg + GP60); 150 outb((t & ~0x0d) | 0x0c, sch311x_wdt_data.runtime_reg + GP60); 151 152 spin_unlock(&sch311x_wdt_data.io_lock); 153 154 } 155 156 static void sch311x_wdt_stop(void) 157 { 158 unsigned char t; 159 160 spin_lock(&sch311x_wdt_data.io_lock); 161 162 /* stop the watchdog */ 163 t = inb(sch311x_wdt_data.runtime_reg + GP60); 164 outb((t & ~0x0d) | 0x01, sch311x_wdt_data.runtime_reg + GP60); 165 /* disable timeout by setting it to 0 */ 166 sch311x_wdt_set_timeout(0); 167 168 spin_unlock(&sch311x_wdt_data.io_lock); 169 } 170 171 static void sch311x_wdt_keepalive(void) 172 { 173 spin_lock(&sch311x_wdt_data.io_lock); 174 sch311x_wdt_set_timeout(timeout); 175 spin_unlock(&sch311x_wdt_data.io_lock); 176 } 177 178 static int sch311x_wdt_set_heartbeat(int t) 179 { 180 if (t < 1 || t > (255*60)) 181 return -EINVAL; 182 183 /* When new timeout is bigger then 255 seconds, 184 * we will round up to minutes (with a max of 255) */ 185 if (t > 255) 186 t = (((t - 1) / 60) + 1) * 60; 187 188 timeout = t; 189 return 0; 190 } 191 192 static void sch311x_wdt_get_status(int *status) 193 { 194 unsigned char new_status; 195 196 *status = 0; 197 198 spin_lock(&sch311x_wdt_data.io_lock); 199 200 /* -- Watchdog timer control -- 201 * Bit 0 Status Bit: 0 = Timer counting, 1 = Timeout occurred 202 * Bit 1 Reserved 203 * Bit 2 Force Timeout: 1 = Forces WD timeout event (self-cleaning) 204 * Bit 3 P20 Force Timeout enabled: 205 * 0 = P20 activity does not generate the WD timeout event 206 * 1 = P20 Allows rising edge of P20, from the keyboard 207 * controller, to force the WD timeout event. 208 * Bit 4-7 Reserved 209 */ 210 new_status = inb(sch311x_wdt_data.runtime_reg + WDT_CTRL); 211 if (new_status & 0x01) 212 *status |= WDIOF_CARDRESET; 213 214 spin_unlock(&sch311x_wdt_data.io_lock); 215 } 216 217 /* 218 * /dev/watchdog handling 219 */ 220 221 static ssize_t sch311x_wdt_write(struct file *file, const char __user *buf, 222 size_t count, loff_t *ppos) 223 { 224 if (count) { 225 if (!nowayout) { 226 size_t i; 227 228 sch311x_wdt_expect_close = 0; 229 230 for (i = 0; i != count; i++) { 231 char c; 232 if (get_user(c, buf + i)) 233 return -EFAULT; 234 if (c == 'V') 235 sch311x_wdt_expect_close = 42; 236 } 237 } 238 sch311x_wdt_keepalive(); 239 } 240 return count; 241 } 242 243 static long sch311x_wdt_ioctl(struct file *file, unsigned int cmd, 244 unsigned long arg) 245 { 246 int status; 247 int new_timeout; 248 void __user *argp = (void __user *)arg; 249 int __user *p = argp; 250 static const struct watchdog_info ident = { 251 .options = WDIOF_KEEPALIVEPING | 252 WDIOF_SETTIMEOUT | 253 WDIOF_MAGICCLOSE, 254 .firmware_version = 1, 255 .identity = DRV_NAME, 256 }; 257 258 switch (cmd) { 259 case WDIOC_GETSUPPORT: 260 if (copy_to_user(argp, &ident, sizeof(ident))) 261 return -EFAULT; 262 break; 263 264 case WDIOC_GETSTATUS: 265 { 266 sch311x_wdt_get_status(&status); 267 return put_user(status, p); 268 } 269 case WDIOC_GETBOOTSTATUS: 270 return put_user(sch311x_wdt_data.boot_status, p); 271 272 case WDIOC_SETOPTIONS: 273 { 274 int options, retval = -EINVAL; 275 276 if (get_user(options, p)) 277 return -EFAULT; 278 if (options & WDIOS_DISABLECARD) { 279 sch311x_wdt_stop(); 280 retval = 0; 281 } 282 if (options & WDIOS_ENABLECARD) { 283 sch311x_wdt_start(); 284 retval = 0; 285 } 286 return retval; 287 } 288 case WDIOC_KEEPALIVE: 289 sch311x_wdt_keepalive(); 290 break; 291 292 case WDIOC_SETTIMEOUT: 293 if (get_user(new_timeout, p)) 294 return -EFAULT; 295 if (sch311x_wdt_set_heartbeat(new_timeout)) 296 return -EINVAL; 297 sch311x_wdt_keepalive(); 298 /* Fall through */ 299 case WDIOC_GETTIMEOUT: 300 return put_user(timeout, p); 301 default: 302 return -ENOTTY; 303 } 304 return 0; 305 } 306 307 static int sch311x_wdt_open(struct inode *inode, struct file *file) 308 { 309 if (test_and_set_bit(0, &sch311x_wdt_is_open)) 310 return -EBUSY; 311 /* 312 * Activate 313 */ 314 sch311x_wdt_start(); 315 return stream_open(inode, file); 316 } 317 318 static int sch311x_wdt_close(struct inode *inode, struct file *file) 319 { 320 if (sch311x_wdt_expect_close == 42) { 321 sch311x_wdt_stop(); 322 } else { 323 pr_crit("Unexpected close, not stopping watchdog!\n"); 324 sch311x_wdt_keepalive(); 325 } 326 clear_bit(0, &sch311x_wdt_is_open); 327 sch311x_wdt_expect_close = 0; 328 return 0; 329 } 330 331 /* 332 * Kernel Interfaces 333 */ 334 335 static const struct file_operations sch311x_wdt_fops = { 336 .owner = THIS_MODULE, 337 .llseek = no_llseek, 338 .write = sch311x_wdt_write, 339 .unlocked_ioctl = sch311x_wdt_ioctl, 340 .open = sch311x_wdt_open, 341 .release = sch311x_wdt_close, 342 }; 343 344 static struct miscdevice sch311x_wdt_miscdev = { 345 .minor = WATCHDOG_MINOR, 346 .name = "watchdog", 347 .fops = &sch311x_wdt_fops, 348 }; 349 350 /* 351 * Init & exit routines 352 */ 353 354 static int sch311x_wdt_probe(struct platform_device *pdev) 355 { 356 struct device *dev = &pdev->dev; 357 int err; 358 359 spin_lock_init(&sch311x_wdt_data.io_lock); 360 361 if (!request_region(sch311x_wdt_data.runtime_reg + GP60, 1, DRV_NAME)) { 362 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n", 363 sch311x_wdt_data.runtime_reg + GP60, 364 sch311x_wdt_data.runtime_reg + GP60); 365 err = -EBUSY; 366 goto exit; 367 } 368 369 if (!request_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4, 370 DRV_NAME)) { 371 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n", 372 sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 373 sch311x_wdt_data.runtime_reg + WDT_CTRL); 374 err = -EBUSY; 375 goto exit_release_region; 376 } 377 378 /* Make sure that the watchdog is not running */ 379 sch311x_wdt_stop(); 380 381 /* Disable keyboard and mouse interaction and interrupt */ 382 /* -- Watchdog timer configuration -- 383 * Bit 0 Reserved 384 * Bit 1 Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr. 385 * Bit 2 Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr 386 * Bit 3 Reserved 387 * Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled, 388 * 0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15) 389 */ 390 outb(0, sch311x_wdt_data.runtime_reg + WDT_CFG); 391 392 /* Check that the heartbeat value is within it's range ; 393 * if not reset to the default */ 394 if (sch311x_wdt_set_heartbeat(timeout)) { 395 sch311x_wdt_set_heartbeat(WATCHDOG_TIMEOUT); 396 dev_info(dev, "timeout value must be 1<=x<=15300, using %d\n", 397 timeout); 398 } 399 400 /* Get status at boot */ 401 sch311x_wdt_get_status(&sch311x_wdt_data.boot_status); 402 403 sch311x_wdt_miscdev.parent = dev; 404 405 err = misc_register(&sch311x_wdt_miscdev); 406 if (err != 0) { 407 dev_err(dev, "cannot register miscdev on minor=%d (err=%d)\n", 408 WATCHDOG_MINOR, err); 409 goto exit_release_region2; 410 } 411 412 dev_info(dev, 413 "SMSC SCH311x WDT initialized. timeout=%d sec (nowayout=%d)\n", 414 timeout, nowayout); 415 416 return 0; 417 418 exit_release_region2: 419 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4); 420 exit_release_region: 421 release_region(sch311x_wdt_data.runtime_reg + GP60, 1); 422 sch311x_wdt_data.runtime_reg = 0; 423 exit: 424 return err; 425 } 426 427 static int sch311x_wdt_remove(struct platform_device *pdev) 428 { 429 /* Stop the timer before we leave */ 430 if (!nowayout) 431 sch311x_wdt_stop(); 432 433 /* Deregister */ 434 misc_deregister(&sch311x_wdt_miscdev); 435 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4); 436 release_region(sch311x_wdt_data.runtime_reg + GP60, 1); 437 sch311x_wdt_data.runtime_reg = 0; 438 return 0; 439 } 440 441 static void sch311x_wdt_shutdown(struct platform_device *dev) 442 { 443 /* Turn the WDT off if we have a soft shutdown */ 444 sch311x_wdt_stop(); 445 } 446 447 static struct platform_driver sch311x_wdt_driver = { 448 .probe = sch311x_wdt_probe, 449 .remove = sch311x_wdt_remove, 450 .shutdown = sch311x_wdt_shutdown, 451 .driver = { 452 .name = DRV_NAME, 453 }, 454 }; 455 456 static int __init sch311x_detect(int sio_config_port, unsigned short *addr) 457 { 458 int err = 0, reg; 459 unsigned short base_addr; 460 unsigned char dev_id; 461 462 sch311x_sio_enter(sio_config_port); 463 464 /* Check device ID. We currently know about: 465 * SCH3112 (0x7c), SCH3114 (0x7d), and SCH3116 (0x7f). */ 466 reg = force_id ? force_id : sch311x_sio_inb(sio_config_port, 0x20); 467 if (!(reg == 0x7c || reg == 0x7d || reg == 0x7f)) { 468 err = -ENODEV; 469 goto exit; 470 } 471 dev_id = reg == 0x7c ? 2 : reg == 0x7d ? 4 : 6; 472 473 /* Select logical device A (runtime registers) */ 474 sch311x_sio_outb(sio_config_port, 0x07, 0x0a); 475 476 /* Check if Logical Device Register is currently active */ 477 if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0) 478 pr_info("Seems that LDN 0x0a is not active...\n"); 479 480 /* Get the base address of the runtime registers */ 481 base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) | 482 sch311x_sio_inb(sio_config_port, 0x61); 483 if (!base_addr) { 484 pr_err("Base address not set\n"); 485 err = -ENODEV; 486 goto exit; 487 } 488 *addr = base_addr; 489 490 pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr); 491 492 exit: 493 sch311x_sio_exit(sio_config_port); 494 return err; 495 } 496 497 static int __init sch311x_wdt_init(void) 498 { 499 int err, i, found = 0; 500 unsigned short addr = 0; 501 502 for (i = 0; !found && sch311x_ioports[i]; i++) 503 if (sch311x_detect(sch311x_ioports[i], &addr) == 0) 504 found++; 505 506 if (!found) 507 return -ENODEV; 508 509 sch311x_wdt_data.runtime_reg = addr; 510 511 err = platform_driver_register(&sch311x_wdt_driver); 512 if (err) 513 return err; 514 515 sch311x_wdt_pdev = platform_device_register_simple(DRV_NAME, addr, 516 NULL, 0); 517 518 if (IS_ERR(sch311x_wdt_pdev)) { 519 err = PTR_ERR(sch311x_wdt_pdev); 520 goto unreg_platform_driver; 521 } 522 523 return 0; 524 525 unreg_platform_driver: 526 platform_driver_unregister(&sch311x_wdt_driver); 527 return err; 528 } 529 530 static void __exit sch311x_wdt_exit(void) 531 { 532 platform_device_unregister(sch311x_wdt_pdev); 533 platform_driver_unregister(&sch311x_wdt_driver); 534 } 535 536 module_init(sch311x_wdt_init); 537 module_exit(sch311x_wdt_exit); 538 539 MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>"); 540 MODULE_DESCRIPTION("SMSC SCH311x WatchDog Timer Driver"); 541 MODULE_LICENSE("GPL"); 542