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/uaccess.h> 32 #include <linux/slab.h> 33 #include "sch56xx-common.h" 34 35 /* Insmod parameters */ 36 static int nowayout = WATCHDOG_NOWAYOUT; 37 module_param(nowayout, int, 0); 38 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" 39 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 40 41 #define SIO_SCH56XX_LD_EM 0x0C /* Embedded uController Logical Dev */ 42 #define SIO_UNLOCK_KEY 0x55 /* Key to enable Super-I/O */ 43 #define SIO_LOCK_KEY 0xAA /* Key to disable Super-I/O */ 44 45 #define SIO_REG_LDSEL 0x07 /* Logical device select */ 46 #define SIO_REG_DEVID 0x20 /* Device ID */ 47 #define SIO_REG_ENABLE 0x30 /* Logical device enable */ 48 #define SIO_REG_ADDR 0x66 /* Logical device address (2 bytes) */ 49 50 #define SIO_SCH5627_ID 0xC6 /* Chipset ID */ 51 #define SIO_SCH5636_ID 0xC7 /* Chipset ID */ 52 53 #define REGION_LENGTH 10 54 55 #define SCH56XX_CMD_READ 0x02 56 #define SCH56XX_CMD_WRITE 0x03 57 58 /* Watchdog registers */ 59 #define SCH56XX_REG_WDOG_PRESET 0x58B 60 #define SCH56XX_REG_WDOG_CONTROL 0x58C 61 #define SCH56XX_WDOG_TIME_BASE_SEC 0x01 62 #define SCH56XX_REG_WDOG_OUTPUT_ENABLE 0x58E 63 #define SCH56XX_WDOG_OUTPUT_ENABLE 0x02 64 65 struct sch56xx_watchdog_data { 66 u16 addr; 67 struct mutex *io_lock; 68 struct watchdog_info wdinfo; 69 struct watchdog_device wddev; 70 u8 watchdog_preset; 71 u8 watchdog_control; 72 u8 watchdog_output_enable; 73 }; 74 75 static struct platform_device *sch56xx_pdev; 76 77 /* Super I/O functions */ 78 static inline int superio_inb(int base, int reg) 79 { 80 outb(reg, base); 81 return inb(base + 1); 82 } 83 84 static inline int superio_enter(int base) 85 { 86 /* Don't step on other drivers' I/O space by accident */ 87 if (!request_muxed_region(base, 2, "sch56xx")) { 88 pr_err("I/O address 0x%04x already in use\n", base); 89 return -EBUSY; 90 } 91 92 outb(SIO_UNLOCK_KEY, base); 93 94 return 0; 95 } 96 97 static inline void superio_select(int base, int ld) 98 { 99 outb(SIO_REG_LDSEL, base); 100 outb(ld, base + 1); 101 } 102 103 static inline void superio_exit(int base) 104 { 105 outb(SIO_LOCK_KEY, base); 106 release_region(base, 2); 107 } 108 109 static int sch56xx_send_cmd(u16 addr, u8 cmd, u16 reg, u8 v) 110 { 111 u8 val; 112 int i; 113 /* 114 * According to SMSC for the commands we use the maximum time for 115 * the EM to respond is 15 ms, but testing shows in practice it 116 * responds within 15-32 reads, so we first busy poll, and if 117 * that fails sleep a bit and try again until we are way past 118 * the 15 ms maximum response time. 119 */ 120 const int max_busy_polls = 64; 121 const int max_lazy_polls = 32; 122 123 /* (Optional) Write-Clear the EC to Host Mailbox Register */ 124 val = inb(addr + 1); 125 outb(val, addr + 1); 126 127 /* Set Mailbox Address Pointer to first location in Region 1 */ 128 outb(0x00, addr + 2); 129 outb(0x80, addr + 3); 130 131 /* Write Request Packet Header */ 132 outb(cmd, addr + 4); /* VREG Access Type read:0x02 write:0x03 */ 133 outb(0x01, addr + 5); /* # of Entries: 1 Byte (8-bit) */ 134 outb(0x04, addr + 2); /* Mailbox AP to first data entry loc. */ 135 136 /* Write Value field */ 137 if (cmd == SCH56XX_CMD_WRITE) 138 outb(v, addr + 4); 139 140 /* Write Address field */ 141 outb(reg & 0xff, addr + 6); 142 outb(reg >> 8, addr + 7); 143 144 /* Execute the Random Access Command */ 145 outb(0x01, addr); /* Write 01h to the Host-to-EC register */ 146 147 /* EM Interface Polling "Algorithm" */ 148 for (i = 0; i < max_busy_polls + max_lazy_polls; i++) { 149 if (i >= max_busy_polls) 150 msleep(1); 151 /* Read Interrupt source Register */ 152 val = inb(addr + 8); 153 /* Write Clear the interrupt source bits */ 154 if (val) 155 outb(val, addr + 8); 156 /* Command Completed ? */ 157 if (val & 0x01) 158 break; 159 } 160 if (i == max_busy_polls + max_lazy_polls) { 161 pr_err("Max retries exceeded reading virtual register 0x%04hx (%d)\n", 162 reg, 1); 163 return -EIO; 164 } 165 166 /* 167 * According to SMSC we may need to retry this, but sofar I've always 168 * seen this succeed in 1 try. 169 */ 170 for (i = 0; i < max_busy_polls; i++) { 171 /* Read EC-to-Host Register */ 172 val = inb(addr + 1); 173 /* Command Completed ? */ 174 if (val == 0x01) 175 break; 176 177 if (i == 0) 178 pr_warn("EC reports: 0x%02x reading virtual register 0x%04hx\n", 179 (unsigned int)val, reg); 180 } 181 if (i == max_busy_polls) { 182 pr_err("Max retries exceeded reading virtual register 0x%04hx (%d)\n", 183 reg, 2); 184 return -EIO; 185 } 186 187 /* 188 * According to the SMSC app note we should now do: 189 * 190 * Set Mailbox Address Pointer to first location in Region 1 * 191 * outb(0x00, addr + 2); 192 * outb(0x80, addr + 3); 193 * 194 * But if we do that things don't work, so let's not. 195 */ 196 197 /* Read Value field */ 198 if (cmd == SCH56XX_CMD_READ) 199 return inb(addr + 4); 200 201 return 0; 202 } 203 204 int sch56xx_read_virtual_reg(u16 addr, u16 reg) 205 { 206 return sch56xx_send_cmd(addr, SCH56XX_CMD_READ, reg, 0); 207 } 208 EXPORT_SYMBOL(sch56xx_read_virtual_reg); 209 210 int sch56xx_write_virtual_reg(u16 addr, u16 reg, u8 val) 211 { 212 return sch56xx_send_cmd(addr, SCH56XX_CMD_WRITE, reg, val); 213 } 214 EXPORT_SYMBOL(sch56xx_write_virtual_reg); 215 216 int sch56xx_read_virtual_reg16(u16 addr, u16 reg) 217 { 218 int lsb, msb; 219 220 /* Read LSB first, this will cause the matching MSB to be latched */ 221 lsb = sch56xx_read_virtual_reg(addr, reg); 222 if (lsb < 0) 223 return lsb; 224 225 msb = sch56xx_read_virtual_reg(addr, reg + 1); 226 if (msb < 0) 227 return msb; 228 229 return lsb | (msb << 8); 230 } 231 EXPORT_SYMBOL(sch56xx_read_virtual_reg16); 232 233 int sch56xx_read_virtual_reg12(u16 addr, u16 msb_reg, u16 lsn_reg, 234 int high_nibble) 235 { 236 int msb, lsn; 237 238 /* Read MSB first, this will cause the matching LSN to be latched */ 239 msb = sch56xx_read_virtual_reg(addr, msb_reg); 240 if (msb < 0) 241 return msb; 242 243 lsn = sch56xx_read_virtual_reg(addr, lsn_reg); 244 if (lsn < 0) 245 return lsn; 246 247 if (high_nibble) 248 return (msb << 4) | (lsn >> 4); 249 else 250 return (msb << 4) | (lsn & 0x0f); 251 } 252 EXPORT_SYMBOL(sch56xx_read_virtual_reg12); 253 254 /* 255 * Watchdog routines 256 */ 257 258 static int watchdog_set_timeout(struct watchdog_device *wddev, 259 unsigned int timeout) 260 { 261 struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev); 262 unsigned int resolution; 263 u8 control; 264 int ret; 265 266 /* 1 second or 60 second resolution? */ 267 if (timeout <= 255) 268 resolution = 1; 269 else 270 resolution = 60; 271 272 if (timeout < resolution || timeout > (resolution * 255)) 273 return -EINVAL; 274 275 if (resolution == 1) 276 control = data->watchdog_control | SCH56XX_WDOG_TIME_BASE_SEC; 277 else 278 control = data->watchdog_control & ~SCH56XX_WDOG_TIME_BASE_SEC; 279 280 if (data->watchdog_control != control) { 281 mutex_lock(data->io_lock); 282 ret = sch56xx_write_virtual_reg(data->addr, 283 SCH56XX_REG_WDOG_CONTROL, 284 control); 285 mutex_unlock(data->io_lock); 286 if (ret) 287 return ret; 288 289 data->watchdog_control = control; 290 } 291 292 /* 293 * Remember new timeout value, but do not write as that (re)starts 294 * the watchdog countdown. 295 */ 296 data->watchdog_preset = DIV_ROUND_UP(timeout, resolution); 297 wddev->timeout = data->watchdog_preset * resolution; 298 299 return 0; 300 } 301 302 static int watchdog_start(struct watchdog_device *wddev) 303 { 304 struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev); 305 int ret; 306 u8 val; 307 308 /* 309 * The sch56xx's watchdog cannot really be started / stopped 310 * it is always running, but we can avoid the timer expiring 311 * from causing a system reset by clearing the output enable bit. 312 * 313 * The sch56xx's watchdog will set the watchdog event bit, bit 0 314 * of the second interrupt source register (at base-address + 9), 315 * when the timer expires. 316 * 317 * This will only cause a system reset if the 0-1 flank happens when 318 * output enable is true. Setting output enable after the flank will 319 * not cause a reset, nor will the timer expiring a second time. 320 * This means we must clear the watchdog event bit in case it is set. 321 * 322 * The timer may still be running (after a recent watchdog_stop) and 323 * mere milliseconds away from expiring, so the timer must be reset 324 * first! 325 */ 326 327 mutex_lock(data->io_lock); 328 329 /* 1. Reset the watchdog countdown counter */ 330 ret = sch56xx_write_virtual_reg(data->addr, SCH56XX_REG_WDOG_PRESET, 331 data->watchdog_preset); 332 if (ret) 333 goto leave; 334 335 /* 2. Enable output */ 336 val = data->watchdog_output_enable | SCH56XX_WDOG_OUTPUT_ENABLE; 337 ret = sch56xx_write_virtual_reg(data->addr, 338 SCH56XX_REG_WDOG_OUTPUT_ENABLE, val); 339 if (ret) 340 goto leave; 341 342 data->watchdog_output_enable = val; 343 344 /* 3. Clear the watchdog event bit if set */ 345 val = inb(data->addr + 9); 346 if (val & 0x01) 347 outb(0x01, data->addr + 9); 348 349 leave: 350 mutex_unlock(data->io_lock); 351 return ret; 352 } 353 354 static int watchdog_trigger(struct watchdog_device *wddev) 355 { 356 struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev); 357 int ret; 358 359 /* Reset the watchdog countdown counter */ 360 mutex_lock(data->io_lock); 361 ret = sch56xx_write_virtual_reg(data->addr, SCH56XX_REG_WDOG_PRESET, 362 data->watchdog_preset); 363 mutex_unlock(data->io_lock); 364 365 return ret; 366 } 367 368 static int watchdog_stop(struct watchdog_device *wddev) 369 { 370 struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev); 371 int ret = 0; 372 u8 val; 373 374 val = data->watchdog_output_enable & ~SCH56XX_WDOG_OUTPUT_ENABLE; 375 mutex_lock(data->io_lock); 376 ret = sch56xx_write_virtual_reg(data->addr, 377 SCH56XX_REG_WDOG_OUTPUT_ENABLE, val); 378 mutex_unlock(data->io_lock); 379 if (ret) 380 return ret; 381 382 data->watchdog_output_enable = val; 383 return 0; 384 } 385 386 static const struct watchdog_ops watchdog_ops = { 387 .owner = THIS_MODULE, 388 .start = watchdog_start, 389 .stop = watchdog_stop, 390 .ping = watchdog_trigger, 391 .set_timeout = watchdog_set_timeout, 392 }; 393 394 struct sch56xx_watchdog_data *sch56xx_watchdog_register(struct device *parent, 395 u16 addr, u32 revision, struct mutex *io_lock, int check_enabled) 396 { 397 struct sch56xx_watchdog_data *data; 398 int err, control, output_enable; 399 400 /* Cache the watchdog registers */ 401 mutex_lock(io_lock); 402 control = 403 sch56xx_read_virtual_reg(addr, SCH56XX_REG_WDOG_CONTROL); 404 output_enable = 405 sch56xx_read_virtual_reg(addr, SCH56XX_REG_WDOG_OUTPUT_ENABLE); 406 mutex_unlock(io_lock); 407 408 if (control < 0) 409 return NULL; 410 if (output_enable < 0) 411 return NULL; 412 if (check_enabled && !(output_enable & SCH56XX_WDOG_OUTPUT_ENABLE)) { 413 pr_warn("Watchdog not enabled by BIOS, not registering\n"); 414 return NULL; 415 } 416 417 data = kzalloc(sizeof(struct sch56xx_watchdog_data), GFP_KERNEL); 418 if (!data) 419 return NULL; 420 421 data->addr = addr; 422 data->io_lock = io_lock; 423 424 strlcpy(data->wdinfo.identity, "sch56xx watchdog", 425 sizeof(data->wdinfo.identity)); 426 data->wdinfo.firmware_version = revision; 427 data->wdinfo.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT; 428 if (!nowayout) 429 data->wdinfo.options |= WDIOF_MAGICCLOSE; 430 431 data->wddev.info = &data->wdinfo; 432 data->wddev.ops = &watchdog_ops; 433 data->wddev.parent = parent; 434 data->wddev.timeout = 60; 435 data->wddev.min_timeout = 1; 436 data->wddev.max_timeout = 255 * 60; 437 if (nowayout) 438 set_bit(WDOG_NO_WAY_OUT, &data->wddev.status); 439 if (output_enable & SCH56XX_WDOG_OUTPUT_ENABLE) 440 set_bit(WDOG_ACTIVE, &data->wddev.status); 441 442 /* Since the watchdog uses a downcounter there is no register to read 443 the BIOS set timeout from (if any was set at all) -> 444 Choose a preset which will give us a 1 minute timeout */ 445 if (control & SCH56XX_WDOG_TIME_BASE_SEC) 446 data->watchdog_preset = 60; /* seconds */ 447 else 448 data->watchdog_preset = 1; /* minute */ 449 450 data->watchdog_control = control; 451 data->watchdog_output_enable = output_enable; 452 453 watchdog_set_drvdata(&data->wddev, data); 454 err = watchdog_register_device(&data->wddev); 455 if (err) { 456 pr_err("Registering watchdog chardev: %d\n", err); 457 kfree(data); 458 return NULL; 459 } 460 461 return data; 462 } 463 EXPORT_SYMBOL(sch56xx_watchdog_register); 464 465 void sch56xx_watchdog_unregister(struct sch56xx_watchdog_data *data) 466 { 467 watchdog_unregister_device(&data->wddev); 468 kfree(data); 469 } 470 EXPORT_SYMBOL(sch56xx_watchdog_unregister); 471 472 /* 473 * platform dev find, add and remove functions 474 */ 475 476 static int __init sch56xx_find(int sioaddr, const char **name) 477 { 478 u8 devid; 479 unsigned short address; 480 int err; 481 482 err = superio_enter(sioaddr); 483 if (err) 484 return err; 485 486 devid = superio_inb(sioaddr, SIO_REG_DEVID); 487 switch (devid) { 488 case SIO_SCH5627_ID: 489 *name = "sch5627"; 490 break; 491 case SIO_SCH5636_ID: 492 *name = "sch5636"; 493 break; 494 default: 495 pr_debug("Unsupported device id: 0x%02x\n", 496 (unsigned int)devid); 497 err = -ENODEV; 498 goto exit; 499 } 500 501 superio_select(sioaddr, SIO_SCH56XX_LD_EM); 502 503 if (!(superio_inb(sioaddr, SIO_REG_ENABLE) & 0x01)) { 504 pr_warn("Device not activated\n"); 505 err = -ENODEV; 506 goto exit; 507 } 508 509 /* 510 * Warning the order of the low / high byte is the other way around 511 * as on most other superio devices!! 512 */ 513 address = superio_inb(sioaddr, SIO_REG_ADDR) | 514 superio_inb(sioaddr, SIO_REG_ADDR + 1) << 8; 515 if (address == 0) { 516 pr_warn("Base address not set\n"); 517 err = -ENODEV; 518 goto exit; 519 } 520 err = address; 521 522 exit: 523 superio_exit(sioaddr); 524 return err; 525 } 526 527 static int __init sch56xx_device_add(int address, const char *name) 528 { 529 struct resource res = { 530 .start = address, 531 .end = address + REGION_LENGTH - 1, 532 .flags = IORESOURCE_IO, 533 }; 534 int err; 535 536 sch56xx_pdev = platform_device_alloc(name, address); 537 if (!sch56xx_pdev) 538 return -ENOMEM; 539 540 res.name = sch56xx_pdev->name; 541 err = acpi_check_resource_conflict(&res); 542 if (err) 543 goto exit_device_put; 544 545 err = platform_device_add_resources(sch56xx_pdev, &res, 1); 546 if (err) { 547 pr_err("Device resource addition failed\n"); 548 goto exit_device_put; 549 } 550 551 err = platform_device_add(sch56xx_pdev); 552 if (err) { 553 pr_err("Device addition failed\n"); 554 goto exit_device_put; 555 } 556 557 return 0; 558 559 exit_device_put: 560 platform_device_put(sch56xx_pdev); 561 562 return err; 563 } 564 565 static int __init sch56xx_init(void) 566 { 567 int address; 568 const char *name = NULL; 569 570 address = sch56xx_find(0x4e, &name); 571 if (address < 0) 572 address = sch56xx_find(0x2e, &name); 573 if (address < 0) 574 return address; 575 576 return sch56xx_device_add(address, name); 577 } 578 579 static void __exit sch56xx_exit(void) 580 { 581 platform_device_unregister(sch56xx_pdev); 582 } 583 584 MODULE_DESCRIPTION("SMSC SCH56xx Hardware Monitoring Common Code"); 585 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); 586 MODULE_LICENSE("GPL"); 587 588 module_init(sch56xx_init); 589 module_exit(sch56xx_exit); 590