1 /*************************************************************************** 2 * Copyright (C) 2010-2012 Hans de Goede <hdegoede@redhat.com> * 3 * * 4 * This program is free software; you can redistribute it and/or modify * 5 * it under the terms of the GNU General Public License as published by * 6 * the Free Software Foundation; either version 2 of the License, or * 7 * (at your option) any later version. * 8 * * 9 * This program is distributed in the hope that it will be useful, * 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of * 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * 12 * GNU General Public License for more details. * 13 * * 14 * You should have received a copy of the GNU General Public License * 15 * along with this program; if not, write to the * 16 * Free Software Foundation, Inc., * 17 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * 18 ***************************************************************************/ 19 20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 21 22 #include <linux/module.h> 23 #include <linux/init.h> 24 #include <linux/platform_device.h> 25 #include <linux/err.h> 26 #include <linux/io.h> 27 #include <linux/acpi.h> 28 #include <linux/delay.h> 29 #include <linux/fs.h> 30 #include <linux/watchdog.h> 31 #include <linux/miscdevice.h> 32 #include <linux/uaccess.h> 33 #include <linux/kref.h> 34 #include <linux/slab.h> 35 #include "sch56xx-common.h" 36 37 /* Insmod parameters */ 38 static int nowayout = WATCHDOG_NOWAYOUT; 39 module_param(nowayout, int, 0); 40 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" 41 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 42 43 #define SIO_SCH56XX_LD_EM 0x0C /* Embedded uController Logical Dev */ 44 #define SIO_UNLOCK_KEY 0x55 /* Key to enable Super-I/O */ 45 #define SIO_LOCK_KEY 0xAA /* Key to disable Super-I/O */ 46 47 #define SIO_REG_LDSEL 0x07 /* Logical device select */ 48 #define SIO_REG_DEVID 0x20 /* Device ID */ 49 #define SIO_REG_ENABLE 0x30 /* Logical device enable */ 50 #define SIO_REG_ADDR 0x66 /* Logical device address (2 bytes) */ 51 52 #define SIO_SCH5627_ID 0xC6 /* Chipset ID */ 53 #define SIO_SCH5636_ID 0xC7 /* Chipset ID */ 54 55 #define REGION_LENGTH 10 56 57 #define SCH56XX_CMD_READ 0x02 58 #define SCH56XX_CMD_WRITE 0x03 59 60 /* Watchdog registers */ 61 #define SCH56XX_REG_WDOG_PRESET 0x58B 62 #define SCH56XX_REG_WDOG_CONTROL 0x58C 63 #define SCH56XX_WDOG_TIME_BASE_SEC 0x01 64 #define SCH56XX_REG_WDOG_OUTPUT_ENABLE 0x58E 65 #define SCH56XX_WDOG_OUTPUT_ENABLE 0x02 66 67 struct sch56xx_watchdog_data { 68 u16 addr; 69 u32 revision; 70 struct mutex *io_lock; 71 struct mutex watchdog_lock; 72 struct list_head list; /* member of the watchdog_data_list */ 73 struct kref kref; 74 struct miscdevice watchdog_miscdev; 75 unsigned long watchdog_is_open; 76 char watchdog_name[10]; /* must be unique to avoid sysfs conflict */ 77 char watchdog_expect_close; 78 u8 watchdog_preset; 79 u8 watchdog_control; 80 u8 watchdog_output_enable; 81 }; 82 83 static struct platform_device *sch56xx_pdev; 84 85 /* 86 * Somewhat ugly :( global data pointer list with all sch56xx devices, so that 87 * we can find our device data as when using misc_register there is no other 88 * method to get to ones device data from the open fop. 89 */ 90 static LIST_HEAD(watchdog_data_list); 91 /* Note this lock not only protect list access, but also data.kref access */ 92 static DEFINE_MUTEX(watchdog_data_mutex); 93 94 /* Super I/O functions */ 95 static inline int superio_inb(int base, int reg) 96 { 97 outb(reg, base); 98 return inb(base + 1); 99 } 100 101 static inline int superio_enter(int base) 102 { 103 /* Don't step on other drivers' I/O space by accident */ 104 if (!request_muxed_region(base, 2, "sch56xx")) { 105 pr_err("I/O address 0x%04x already in use\n", base); 106 return -EBUSY; 107 } 108 109 outb(SIO_UNLOCK_KEY, base); 110 111 return 0; 112 } 113 114 static inline void superio_select(int base, int ld) 115 { 116 outb(SIO_REG_LDSEL, base); 117 outb(ld, base + 1); 118 } 119 120 static inline void superio_exit(int base) 121 { 122 outb(SIO_LOCK_KEY, base); 123 release_region(base, 2); 124 } 125 126 static int sch56xx_send_cmd(u16 addr, u8 cmd, u16 reg, u8 v) 127 { 128 u8 val; 129 int i; 130 /* 131 * According to SMSC for the commands we use the maximum time for 132 * the EM to respond is 15 ms, but testing shows in practice it 133 * responds within 15-32 reads, so we first busy poll, and if 134 * that fails sleep a bit and try again until we are way past 135 * the 15 ms maximum response time. 136 */ 137 const int max_busy_polls = 64; 138 const int max_lazy_polls = 32; 139 140 /* (Optional) Write-Clear the EC to Host Mailbox Register */ 141 val = inb(addr + 1); 142 outb(val, addr + 1); 143 144 /* Set Mailbox Address Pointer to first location in Region 1 */ 145 outb(0x00, addr + 2); 146 outb(0x80, addr + 3); 147 148 /* Write Request Packet Header */ 149 outb(cmd, addr + 4); /* VREG Access Type read:0x02 write:0x03 */ 150 outb(0x01, addr + 5); /* # of Entries: 1 Byte (8-bit) */ 151 outb(0x04, addr + 2); /* Mailbox AP to first data entry loc. */ 152 153 /* Write Value field */ 154 if (cmd == SCH56XX_CMD_WRITE) 155 outb(v, addr + 4); 156 157 /* Write Address field */ 158 outb(reg & 0xff, addr + 6); 159 outb(reg >> 8, addr + 7); 160 161 /* Execute the Random Access Command */ 162 outb(0x01, addr); /* Write 01h to the Host-to-EC register */ 163 164 /* EM Interface Polling "Algorithm" */ 165 for (i = 0; i < max_busy_polls + max_lazy_polls; i++) { 166 if (i >= max_busy_polls) 167 msleep(1); 168 /* Read Interrupt source Register */ 169 val = inb(addr + 8); 170 /* Write Clear the interrupt source bits */ 171 if (val) 172 outb(val, addr + 8); 173 /* Command Completed ? */ 174 if (val & 0x01) 175 break; 176 } 177 if (i == max_busy_polls + max_lazy_polls) { 178 pr_err("Max retries exceeded reading virtual " 179 "register 0x%04hx (%d)\n", reg, 1); 180 return -EIO; 181 } 182 183 /* 184 * According to SMSC we may need to retry this, but sofar I've always 185 * seen this succeed in 1 try. 186 */ 187 for (i = 0; i < max_busy_polls; i++) { 188 /* Read EC-to-Host Register */ 189 val = inb(addr + 1); 190 /* Command Completed ? */ 191 if (val == 0x01) 192 break; 193 194 if (i == 0) 195 pr_warn("EC reports: 0x%02x reading virtual register " 196 "0x%04hx\n", (unsigned int)val, reg); 197 } 198 if (i == max_busy_polls) { 199 pr_err("Max retries exceeded reading virtual " 200 "register 0x%04hx (%d)\n", reg, 2); 201 return -EIO; 202 } 203 204 /* 205 * According to the SMSC app note we should now do: 206 * 207 * Set Mailbox Address Pointer to first location in Region 1 * 208 * outb(0x00, addr + 2); 209 * outb(0x80, addr + 3); 210 * 211 * But if we do that things don't work, so let's not. 212 */ 213 214 /* Read Value field */ 215 if (cmd == SCH56XX_CMD_READ) 216 return inb(addr + 4); 217 218 return 0; 219 } 220 221 int sch56xx_read_virtual_reg(u16 addr, u16 reg) 222 { 223 return sch56xx_send_cmd(addr, SCH56XX_CMD_READ, reg, 0); 224 } 225 EXPORT_SYMBOL(sch56xx_read_virtual_reg); 226 227 int sch56xx_write_virtual_reg(u16 addr, u16 reg, u8 val) 228 { 229 return sch56xx_send_cmd(addr, SCH56XX_CMD_WRITE, reg, val); 230 } 231 EXPORT_SYMBOL(sch56xx_write_virtual_reg); 232 233 int sch56xx_read_virtual_reg16(u16 addr, u16 reg) 234 { 235 int lsb, msb; 236 237 /* Read LSB first, this will cause the matching MSB to be latched */ 238 lsb = sch56xx_read_virtual_reg(addr, reg); 239 if (lsb < 0) 240 return lsb; 241 242 msb = sch56xx_read_virtual_reg(addr, reg + 1); 243 if (msb < 0) 244 return msb; 245 246 return lsb | (msb << 8); 247 } 248 EXPORT_SYMBOL(sch56xx_read_virtual_reg16); 249 250 int sch56xx_read_virtual_reg12(u16 addr, u16 msb_reg, u16 lsn_reg, 251 int high_nibble) 252 { 253 int msb, lsn; 254 255 /* Read MSB first, this will cause the matching LSN to be latched */ 256 msb = sch56xx_read_virtual_reg(addr, msb_reg); 257 if (msb < 0) 258 return msb; 259 260 lsn = sch56xx_read_virtual_reg(addr, lsn_reg); 261 if (lsn < 0) 262 return lsn; 263 264 if (high_nibble) 265 return (msb << 4) | (lsn >> 4); 266 else 267 return (msb << 4) | (lsn & 0x0f); 268 } 269 EXPORT_SYMBOL(sch56xx_read_virtual_reg12); 270 271 /* 272 * Watchdog routines 273 */ 274 275 /* 276 * Release our data struct when the platform device has been released *and* 277 * all references to our watchdog device are released. 278 */ 279 static void sch56xx_watchdog_release_resources(struct kref *r) 280 { 281 struct sch56xx_watchdog_data *data = 282 container_of(r, struct sch56xx_watchdog_data, kref); 283 kfree(data); 284 } 285 286 static int watchdog_set_timeout(struct sch56xx_watchdog_data *data, 287 int timeout) 288 { 289 int ret, resolution; 290 u8 control; 291 292 /* 1 second or 60 second resolution? */ 293 if (timeout <= 255) 294 resolution = 1; 295 else 296 resolution = 60; 297 298 if (timeout < resolution || timeout > (resolution * 255)) 299 return -EINVAL; 300 301 mutex_lock(&data->watchdog_lock); 302 if (!data->addr) { 303 ret = -ENODEV; 304 goto leave; 305 } 306 307 if (resolution == 1) 308 control = data->watchdog_control | SCH56XX_WDOG_TIME_BASE_SEC; 309 else 310 control = data->watchdog_control & ~SCH56XX_WDOG_TIME_BASE_SEC; 311 312 if (data->watchdog_control != control) { 313 mutex_lock(data->io_lock); 314 ret = sch56xx_write_virtual_reg(data->addr, 315 SCH56XX_REG_WDOG_CONTROL, 316 control); 317 mutex_unlock(data->io_lock); 318 if (ret) 319 goto leave; 320 321 data->watchdog_control = control; 322 } 323 324 /* 325 * Remember new timeout value, but do not write as that (re)starts 326 * the watchdog countdown. 327 */ 328 data->watchdog_preset = DIV_ROUND_UP(timeout, resolution); 329 330 ret = data->watchdog_preset * resolution; 331 leave: 332 mutex_unlock(&data->watchdog_lock); 333 return ret; 334 } 335 336 static int watchdog_get_timeout(struct sch56xx_watchdog_data *data) 337 { 338 int timeout; 339 340 mutex_lock(&data->watchdog_lock); 341 if (data->watchdog_control & SCH56XX_WDOG_TIME_BASE_SEC) 342 timeout = data->watchdog_preset; 343 else 344 timeout = data->watchdog_preset * 60; 345 mutex_unlock(&data->watchdog_lock); 346 347 return timeout; 348 } 349 350 static int watchdog_start(struct sch56xx_watchdog_data *data) 351 { 352 int ret; 353 u8 val; 354 355 mutex_lock(&data->watchdog_lock); 356 if (!data->addr) { 357 ret = -ENODEV; 358 goto leave_unlock_watchdog; 359 } 360 361 /* 362 * The sch56xx's watchdog cannot really be started / stopped 363 * it is always running, but we can avoid the timer expiring 364 * from causing a system reset by clearing the output enable bit. 365 * 366 * The sch56xx's watchdog will set the watchdog event bit, bit 0 367 * of the second interrupt source register (at base-address + 9), 368 * when the timer expires. 369 * 370 * This will only cause a system reset if the 0-1 flank happens when 371 * output enable is true. Setting output enable after the flank will 372 * not cause a reset, nor will the timer expiring a second time. 373 * This means we must clear the watchdog event bit in case it is set. 374 * 375 * The timer may still be running (after a recent watchdog_stop) and 376 * mere milliseconds away from expiring, so the timer must be reset 377 * first! 378 */ 379 380 mutex_lock(data->io_lock); 381 382 /* 1. Reset the watchdog countdown counter */ 383 ret = sch56xx_write_virtual_reg(data->addr, SCH56XX_REG_WDOG_PRESET, 384 data->watchdog_preset); 385 if (ret) 386 goto leave; 387 388 /* 2. Enable output (if not already enabled) */ 389 if (!(data->watchdog_output_enable & SCH56XX_WDOG_OUTPUT_ENABLE)) { 390 val = data->watchdog_output_enable | 391 SCH56XX_WDOG_OUTPUT_ENABLE; 392 ret = sch56xx_write_virtual_reg(data->addr, 393 SCH56XX_REG_WDOG_OUTPUT_ENABLE, 394 val); 395 if (ret) 396 goto leave; 397 398 data->watchdog_output_enable = val; 399 } 400 401 /* 3. Clear the watchdog event bit if set */ 402 val = inb(data->addr + 9); 403 if (val & 0x01) 404 outb(0x01, data->addr + 9); 405 406 leave: 407 mutex_unlock(data->io_lock); 408 leave_unlock_watchdog: 409 mutex_unlock(&data->watchdog_lock); 410 return ret; 411 } 412 413 static int watchdog_trigger(struct sch56xx_watchdog_data *data) 414 { 415 int ret; 416 417 mutex_lock(&data->watchdog_lock); 418 if (!data->addr) { 419 ret = -ENODEV; 420 goto leave; 421 } 422 423 /* Reset the watchdog countdown counter */ 424 mutex_lock(data->io_lock); 425 ret = sch56xx_write_virtual_reg(data->addr, SCH56XX_REG_WDOG_PRESET, 426 data->watchdog_preset); 427 mutex_unlock(data->io_lock); 428 leave: 429 mutex_unlock(&data->watchdog_lock); 430 return ret; 431 } 432 433 static int watchdog_stop_unlocked(struct sch56xx_watchdog_data *data) 434 { 435 int ret = 0; 436 u8 val; 437 438 if (!data->addr) 439 return -ENODEV; 440 441 if (data->watchdog_output_enable & SCH56XX_WDOG_OUTPUT_ENABLE) { 442 val = data->watchdog_output_enable & 443 ~SCH56XX_WDOG_OUTPUT_ENABLE; 444 mutex_lock(data->io_lock); 445 ret = sch56xx_write_virtual_reg(data->addr, 446 SCH56XX_REG_WDOG_OUTPUT_ENABLE, 447 val); 448 mutex_unlock(data->io_lock); 449 if (ret) 450 return ret; 451 452 data->watchdog_output_enable = val; 453 } 454 455 return ret; 456 } 457 458 static int watchdog_stop(struct sch56xx_watchdog_data *data) 459 { 460 int ret; 461 462 mutex_lock(&data->watchdog_lock); 463 ret = watchdog_stop_unlocked(data); 464 mutex_unlock(&data->watchdog_lock); 465 466 return ret; 467 } 468 469 static int watchdog_release(struct inode *inode, struct file *filp) 470 { 471 struct sch56xx_watchdog_data *data = filp->private_data; 472 473 if (data->watchdog_expect_close) { 474 watchdog_stop(data); 475 data->watchdog_expect_close = 0; 476 } else { 477 watchdog_trigger(data); 478 pr_crit("unexpected close, not stopping watchdog!\n"); 479 } 480 481 clear_bit(0, &data->watchdog_is_open); 482 483 mutex_lock(&watchdog_data_mutex); 484 kref_put(&data->kref, sch56xx_watchdog_release_resources); 485 mutex_unlock(&watchdog_data_mutex); 486 487 return 0; 488 } 489 490 static int watchdog_open(struct inode *inode, struct file *filp) 491 { 492 struct sch56xx_watchdog_data *pos, *data = NULL; 493 int ret, watchdog_is_open; 494 495 /* 496 * We get called from drivers/char/misc.c with misc_mtx hold, and we 497 * call misc_register() from sch56xx_watchdog_probe() with 498 * watchdog_data_mutex hold, as misc_register() takes the misc_mtx 499 * lock, this is a possible deadlock, so we use mutex_trylock here. 500 */ 501 if (!mutex_trylock(&watchdog_data_mutex)) 502 return -ERESTARTSYS; 503 list_for_each_entry(pos, &watchdog_data_list, list) { 504 if (pos->watchdog_miscdev.minor == iminor(inode)) { 505 data = pos; 506 break; 507 } 508 } 509 /* Note we can never not have found data, so we don't check for this */ 510 watchdog_is_open = test_and_set_bit(0, &data->watchdog_is_open); 511 if (!watchdog_is_open) 512 kref_get(&data->kref); 513 mutex_unlock(&watchdog_data_mutex); 514 515 if (watchdog_is_open) 516 return -EBUSY; 517 518 filp->private_data = data; 519 520 /* Start the watchdog */ 521 ret = watchdog_start(data); 522 if (ret) { 523 watchdog_release(inode, filp); 524 return ret; 525 } 526 527 return nonseekable_open(inode, filp); 528 } 529 530 static ssize_t watchdog_write(struct file *filp, const char __user *buf, 531 size_t count, loff_t *offset) 532 { 533 int ret; 534 struct sch56xx_watchdog_data *data = filp->private_data; 535 536 if (count) { 537 if (!nowayout) { 538 size_t i; 539 540 /* Clear it in case it was set with a previous write */ 541 data->watchdog_expect_close = 0; 542 543 for (i = 0; i != count; i++) { 544 char c; 545 if (get_user(c, buf + i)) 546 return -EFAULT; 547 if (c == 'V') 548 data->watchdog_expect_close = 1; 549 } 550 } 551 ret = watchdog_trigger(data); 552 if (ret) 553 return ret; 554 } 555 return count; 556 } 557 558 static long watchdog_ioctl(struct file *filp, unsigned int cmd, 559 unsigned long arg) 560 { 561 struct watchdog_info ident = { 562 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, 563 .identity = "sch56xx watchdog" 564 }; 565 int i, ret = 0; 566 struct sch56xx_watchdog_data *data = filp->private_data; 567 568 switch (cmd) { 569 case WDIOC_GETSUPPORT: 570 ident.firmware_version = data->revision; 571 if (!nowayout) 572 ident.options |= WDIOF_MAGICCLOSE; 573 if (copy_to_user((void __user *)arg, &ident, sizeof(ident))) 574 ret = -EFAULT; 575 break; 576 577 case WDIOC_GETSTATUS: 578 case WDIOC_GETBOOTSTATUS: 579 ret = put_user(0, (int __user *)arg); 580 break; 581 582 case WDIOC_KEEPALIVE: 583 ret = watchdog_trigger(data); 584 break; 585 586 case WDIOC_GETTIMEOUT: 587 i = watchdog_get_timeout(data); 588 ret = put_user(i, (int __user *)arg); 589 break; 590 591 case WDIOC_SETTIMEOUT: 592 if (get_user(i, (int __user *)arg)) { 593 ret = -EFAULT; 594 break; 595 } 596 ret = watchdog_set_timeout(data, i); 597 if (ret >= 0) 598 ret = put_user(ret, (int __user *)arg); 599 break; 600 601 case WDIOC_SETOPTIONS: 602 if (get_user(i, (int __user *)arg)) { 603 ret = -EFAULT; 604 break; 605 } 606 607 if (i & WDIOS_DISABLECARD) 608 ret = watchdog_stop(data); 609 else if (i & WDIOS_ENABLECARD) 610 ret = watchdog_trigger(data); 611 else 612 ret = -EINVAL; 613 break; 614 615 default: 616 ret = -ENOTTY; 617 } 618 return ret; 619 } 620 621 static const struct file_operations watchdog_fops = { 622 .owner = THIS_MODULE, 623 .llseek = no_llseek, 624 .open = watchdog_open, 625 .release = watchdog_release, 626 .write = watchdog_write, 627 .unlocked_ioctl = watchdog_ioctl, 628 }; 629 630 struct sch56xx_watchdog_data *sch56xx_watchdog_register( 631 u16 addr, u32 revision, struct mutex *io_lock, int check_enabled) 632 { 633 struct sch56xx_watchdog_data *data; 634 int i, err, control, output_enable; 635 const int watchdog_minors[] = { WATCHDOG_MINOR, 212, 213, 214, 215 }; 636 637 /* Cache the watchdog registers */ 638 mutex_lock(io_lock); 639 control = 640 sch56xx_read_virtual_reg(addr, SCH56XX_REG_WDOG_CONTROL); 641 output_enable = 642 sch56xx_read_virtual_reg(addr, SCH56XX_REG_WDOG_OUTPUT_ENABLE); 643 mutex_unlock(io_lock); 644 645 if (control < 0) 646 return NULL; 647 if (output_enable < 0) 648 return NULL; 649 if (check_enabled && !(output_enable & SCH56XX_WDOG_OUTPUT_ENABLE)) { 650 pr_warn("Watchdog not enabled by BIOS, not registering\n"); 651 return NULL; 652 } 653 654 data = kzalloc(sizeof(struct sch56xx_watchdog_data), GFP_KERNEL); 655 if (!data) 656 return NULL; 657 658 data->addr = addr; 659 data->revision = revision; 660 data->io_lock = io_lock; 661 data->watchdog_control = control; 662 data->watchdog_output_enable = output_enable; 663 mutex_init(&data->watchdog_lock); 664 INIT_LIST_HEAD(&data->list); 665 kref_init(&data->kref); 666 667 err = watchdog_set_timeout(data, 60); 668 if (err < 0) 669 goto error; 670 671 /* 672 * We take the data_mutex lock early so that watchdog_open() cannot 673 * run when misc_register() has completed, but we've not yet added 674 * our data to the watchdog_data_list. 675 */ 676 mutex_lock(&watchdog_data_mutex); 677 for (i = 0; i < ARRAY_SIZE(watchdog_minors); i++) { 678 /* Register our watchdog part */ 679 snprintf(data->watchdog_name, sizeof(data->watchdog_name), 680 "watchdog%c", (i == 0) ? '\0' : ('0' + i)); 681 data->watchdog_miscdev.name = data->watchdog_name; 682 data->watchdog_miscdev.fops = &watchdog_fops; 683 data->watchdog_miscdev.minor = watchdog_minors[i]; 684 err = misc_register(&data->watchdog_miscdev); 685 if (err == -EBUSY) 686 continue; 687 if (err) 688 break; 689 690 list_add(&data->list, &watchdog_data_list); 691 pr_info("Registered /dev/%s chardev major 10, minor: %d\n", 692 data->watchdog_name, watchdog_minors[i]); 693 break; 694 } 695 mutex_unlock(&watchdog_data_mutex); 696 697 if (err) { 698 pr_err("Registering watchdog chardev: %d\n", err); 699 goto error; 700 } 701 if (i == ARRAY_SIZE(watchdog_minors)) { 702 pr_warn("Couldn't register watchdog (no free minor)\n"); 703 goto error; 704 } 705 706 return data; 707 708 error: 709 kfree(data); 710 return NULL; 711 } 712 EXPORT_SYMBOL(sch56xx_watchdog_register); 713 714 void sch56xx_watchdog_unregister(struct sch56xx_watchdog_data *data) 715 { 716 mutex_lock(&watchdog_data_mutex); 717 misc_deregister(&data->watchdog_miscdev); 718 list_del(&data->list); 719 mutex_unlock(&watchdog_data_mutex); 720 721 mutex_lock(&data->watchdog_lock); 722 if (data->watchdog_is_open) { 723 pr_warn("platform device unregistered with watchdog " 724 "open! Stopping watchdog.\n"); 725 watchdog_stop_unlocked(data); 726 } 727 /* Tell the wdog start/stop/trigger functions our dev is gone */ 728 data->addr = 0; 729 data->io_lock = NULL; 730 mutex_unlock(&data->watchdog_lock); 731 732 mutex_lock(&watchdog_data_mutex); 733 kref_put(&data->kref, sch56xx_watchdog_release_resources); 734 mutex_unlock(&watchdog_data_mutex); 735 } 736 EXPORT_SYMBOL(sch56xx_watchdog_unregister); 737 738 /* 739 * platform dev find, add and remove functions 740 */ 741 742 static int __init sch56xx_find(int sioaddr, unsigned short *address, 743 const char **name) 744 { 745 u8 devid; 746 int err; 747 748 err = superio_enter(sioaddr); 749 if (err) 750 return err; 751 752 devid = superio_inb(sioaddr, SIO_REG_DEVID); 753 switch (devid) { 754 case SIO_SCH5627_ID: 755 *name = "sch5627"; 756 break; 757 case SIO_SCH5636_ID: 758 *name = "sch5636"; 759 break; 760 default: 761 pr_debug("Unsupported device id: 0x%02x\n", 762 (unsigned int)devid); 763 err = -ENODEV; 764 goto exit; 765 } 766 767 superio_select(sioaddr, SIO_SCH56XX_LD_EM); 768 769 if (!(superio_inb(sioaddr, SIO_REG_ENABLE) & 0x01)) { 770 pr_warn("Device not activated\n"); 771 err = -ENODEV; 772 goto exit; 773 } 774 775 /* 776 * Warning the order of the low / high byte is the other way around 777 * as on most other superio devices!! 778 */ 779 *address = superio_inb(sioaddr, SIO_REG_ADDR) | 780 superio_inb(sioaddr, SIO_REG_ADDR + 1) << 8; 781 if (*address == 0) { 782 pr_warn("Base address not set\n"); 783 err = -ENODEV; 784 goto exit; 785 } 786 787 exit: 788 superio_exit(sioaddr); 789 return err; 790 } 791 792 static int __init sch56xx_device_add(unsigned short address, const char *name) 793 { 794 struct resource res = { 795 .start = address, 796 .end = address + REGION_LENGTH - 1, 797 .flags = IORESOURCE_IO, 798 }; 799 int err; 800 801 sch56xx_pdev = platform_device_alloc(name, address); 802 if (!sch56xx_pdev) 803 return -ENOMEM; 804 805 res.name = sch56xx_pdev->name; 806 err = acpi_check_resource_conflict(&res); 807 if (err) 808 goto exit_device_put; 809 810 err = platform_device_add_resources(sch56xx_pdev, &res, 1); 811 if (err) { 812 pr_err("Device resource addition failed\n"); 813 goto exit_device_put; 814 } 815 816 err = platform_device_add(sch56xx_pdev); 817 if (err) { 818 pr_err("Device addition failed\n"); 819 goto exit_device_put; 820 } 821 822 return 0; 823 824 exit_device_put: 825 platform_device_put(sch56xx_pdev); 826 827 return err; 828 } 829 830 static int __init sch56xx_init(void) 831 { 832 int err; 833 unsigned short address; 834 const char *name; 835 836 err = sch56xx_find(0x4e, &address, &name); 837 if (err) 838 err = sch56xx_find(0x2e, &address, &name); 839 if (err) 840 return err; 841 842 return sch56xx_device_add(address, name); 843 } 844 845 static void __exit sch56xx_exit(void) 846 { 847 platform_device_unregister(sch56xx_pdev); 848 } 849 850 MODULE_DESCRIPTION("SMSC SCH56xx Hardware Monitoring Common Code"); 851 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); 852 MODULE_LICENSE("GPL"); 853 854 module_init(sch56xx_init); 855 module_exit(sch56xx_exit); 856