drivers/char/toshiba.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* toshiba.c -- Linux driver for accessing the SMM on Toshiba laptops
   3  *
   4  * Copyright (c) 1996-2001  Jonathan A. Buzzard (jonathan@buzzard.org.uk)
   5  *
   6  * Valuable assistance and patches from:
   7  *     Tom May <tom@you-bastards.com>
   8  *     Rob Napier <rnapier@employees.org>
   9  *
  10  * Fn status port numbers for machine ID's courtesy of
  11  *     0xfc02: Scott Eisert <scott.e@sky-eye.com>
  12  *     0xfc04: Steve VanDevender <stevev@efn.org>
  13  *     0xfc08: Garth Berry <garth@itsbruce.net>
  14  *     0xfc0a: Egbert Eich <eich@xfree86.org>
  15  *     0xfc10: Andrew Lofthouse <Andrew.Lofthouse@robins.af.mil>
  16  *     0xfc11: Spencer Olson <solson@novell.com>
  17  *     0xfc13: Claudius Frankewitz <kryp@gmx.de>
  18  *     0xfc15: Tom May <tom@you-bastards.com>
  19  *     0xfc17: Dave Konrad <konrad@xenia.it>
  20  *     0xfc1a: George Betzos <betzos@engr.colostate.edu>
  21  *     0xfc1b: Munemasa Wada <munemasa@jnovel.co.jp>
  22  *     0xfc1d: Arthur Liu <armie@slap.mine.nu>
  23  *     0xfc5a: Jacques L'helgoualc'h <lhh@free.fr>
  24  *     0xfcd1: Mr. Dave Konrad <konrad@xenia.it>
  25  *
  26  * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
  27  *
  28  *   This code is covered by the GNU GPL and you are free to make any
  29  *   changes you wish to it under the terms of the license. However the
  30  *   code has the potential to render your computer and/or someone else's
  31  *   unusable. Please proceed with care when modifying the code.
  32  *
  33  * Note: Unfortunately the laptop hardware can close the System Configuration
  34  *       Interface on it's own accord. It is therefore necessary for *all*
  35  *       programs using this driver to be aware that *any* SCI call can fail at
  36  *       *any* time. It is up to any program to be aware of this eventuality
  37  *       and take appropriate steps.
  38  *
  39  * The information used to write this driver has been obtained by reverse
  40  * engineering the software supplied by Toshiba for their portable computers in
  41  * strict accordance with the European Council Directive 92/250/EEC on the legal
  42  * protection of computer programs, and it's implementation into English Law by
  43  * the Copyright (Computer Programs) Regulations 1992 (S.I. 1992 No.3233).
  44  */
  45
  46 #define TOSH_VERSION "1.11 26/9/2001"
  47 #define TOSH_DEBUG 0
  48
  49 #include <linux/module.h>
  50 #include <linux/kernel.h>
  51 #include <linux/types.h>
  52 #include <linux/fcntl.h>
  53 #include <linux/miscdevice.h>
  54 #include <linux/ioport.h>
  55 #include <asm/io.h>
  56 #include <linux/uaccess.h>
  57 #include <linux/init.h>
  58 #include <linux/stat.h>
  59 #include <linux/proc_fs.h>
  60 #include <linux/seq_file.h>
  61 #include <linux/mutex.h>
  62 #include <linux/toshiba.h>
  63
  64 MODULE_LICENSE("GPL");
  65 MODULE_AUTHOR("Jonathan Buzzard <jonathan@buzzard.org.uk>");
  66 MODULE_DESCRIPTION("Toshiba laptop SMM driver");
  67 MODULE_SUPPORTED_DEVICE("toshiba");
  68
  69 static DEFINE_MUTEX(tosh_mutex);
  70 static int tosh_fn;
  71 module_param_named(fn, tosh_fn, int, 0);
  72 MODULE_PARM_DESC(fn, "User specified Fn key detection port");
  73
  74 static int tosh_id;
  75 static int tosh_bios;
  76 static int tosh_date;
  77 static int tosh_sci;
  78 static int tosh_fan;
  79
  80 static long tosh_ioctl(struct file *, unsigned int,
  81         unsigned long);
  82
  83
  84 static const struct file_operations tosh_fops = {
  85         .owner          = THIS_MODULE,
  86         .unlocked_ioctl = tosh_ioctl,
  87         .llseek         = noop_llseek,
  88 };
  89
  90 static struct miscdevice tosh_device = {
  91         TOSH_MINOR_DEV,
  92         "toshiba",
  93         &tosh_fops
  94 };
  95
  96 /*
  97  * Read the Fn key status
  98  */
  99 #ifdef CONFIG_PROC_FS
 100 static int tosh_fn_status(void)
 101 {
 102         unsigned char scan;
 103         unsigned long flags;
 104
 105         if (tosh_fn!=0) {
 106                 scan = inb(tosh_fn);
 107         } else {
 108                 local_irq_save(flags);
 109                 outb(0x8e, 0xe4);
 110                 scan = inb(0xe5);
 111                 local_irq_restore(flags);
 112         }
 113
 114         return (int) scan;
 115 }
 116 #endif
 117
 118
 119 /*
 120  * For the Portage 610CT and the Tecra 700CS/700CDT emulate the HCI fan function
 121  */
 122 static int tosh_emulate_fan(SMMRegisters *regs)
 123 {
 124         unsigned long eax,ecx,flags;
 125         unsigned char al;
 126
 127         eax = regs->eax & 0xff00;
 128         ecx = regs->ecx & 0xffff;
 129
 130         /* Portage 610CT */
 131
 132         if (tosh_id==0xfccb) {
 133                 if (eax==0xfe00) {
 134                         /* fan status */
 135                         local_irq_save(flags);
 136                         outb(0xbe, 0xe4);
 137                         al = inb(0xe5);
 138                         local_irq_restore(flags);
 139                         regs->eax = 0x00;
 140                         regs->ecx = (unsigned int) (al & 0x01);
 141                 }
 142                 if ((eax==0xff00) && (ecx==0x0000)) {
 143                         /* fan off */
 144                         local_irq_save(flags);
 145                         outb(0xbe, 0xe4);
 146                         al = inb(0xe5);
 147                         outb(0xbe, 0xe4);
 148                         outb (al | 0x01, 0xe5);
 149                         local_irq_restore(flags);
 150                         regs->eax = 0x00;
 151                         regs->ecx = 0x00;
 152                 }
 153                 if ((eax==0xff00) && (ecx==0x0001)) {
 154                         /* fan on */
 155                         local_irq_save(flags);
 156                         outb(0xbe, 0xe4);
 157                         al = inb(0xe5);
 158                         outb(0xbe, 0xe4);
 159                         outb(al & 0xfe, 0xe5);
 160                         local_irq_restore(flags);
 161                         regs->eax = 0x00;
 162                         regs->ecx = 0x01;
 163                 }
 164         }
 165
 166         /* Tecra 700CS/CDT */
 167
 168         if (tosh_id==0xfccc) {
 169                 if (eax==0xfe00) {
 170                         /* fan status */
 171                         local_irq_save(flags);
 172                         outb(0xe0, 0xe4);
 173                         al = inb(0xe5);
 174                         local_irq_restore(flags);
 175                         regs->eax = 0x00;
 176                         regs->ecx = al & 0x01;
 177                 }
 178                 if ((eax==0xff00) && (ecx==0x0000)) {
 179                         /* fan off */
 180                         local_irq_save(flags);
 181                         outb(0xe0, 0xe4);
 182                         al = inb(0xe5);
 183                         outw(0xe0 | ((al & 0xfe) << 8), 0xe4);
 184                         local_irq_restore(flags);
 185                         regs->eax = 0x00;
 186                         regs->ecx = 0x00;
 187                 }
 188                 if ((eax==0xff00) && (ecx==0x0001)) {
 189                         /* fan on */
 190                         local_irq_save(flags);
 191                         outb(0xe0, 0xe4);
 192                         al = inb(0xe5);
 193                         outw(0xe0 | ((al | 0x01) << 8), 0xe4);
 194                         local_irq_restore(flags);
 195                         regs->eax = 0x00;
 196                         regs->ecx = 0x01;
 197                 }
 198         }
 199
 200         return 0;
 201 }
 202
 203
 204 /*
 205  * Put the laptop into System Management Mode
 206  */
 207 int tosh_smm(SMMRegisters *regs)
 208 {
 209         int eax;
 210
 211         asm ("# load the values into the registers\n\t" \
 212                 "pushl %%eax\n\t" \
 213                 "movl 0(%%eax),%%edx\n\t" \
 214                 "push %%edx\n\t" \
 215                 "movl 4(%%eax),%%ebx\n\t" \
 216                 "movl 8(%%eax),%%ecx\n\t" \
 217                 "movl 12(%%eax),%%edx\n\t" \
 218                 "movl 16(%%eax),%%esi\n\t" \
 219                 "movl 20(%%eax),%%edi\n\t" \
 220                 "popl %%eax\n\t" \
 221                 "# call the System Management mode\n\t" \
 222                 "inb $0xb2,%%al\n\t"
 223                 "# fill out the memory with the values in the registers\n\t" \
 224                 "xchgl %%eax,(%%esp)\n\t"
 225                 "movl %%ebx,4(%%eax)\n\t" \
 226                 "movl %%ecx,8(%%eax)\n\t" \
 227                 "movl %%edx,12(%%eax)\n\t" \
 228                 "movl %%esi,16(%%eax)\n\t" \
 229                 "movl %%edi,20(%%eax)\n\t" \
 230                 "popl %%edx\n\t" \
 231                 "movl %%edx,0(%%eax)\n\t" \
 232                 "# setup the return value to the carry flag\n\t" \
 233                 "lahf\n\t" \
 234                 "shrl $8,%%eax\n\t" \
 235                 "andl $1,%%eax\n" \
 236                 : "=a" (eax)
 237                 : "a" (regs)
 238                 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
 239
 240         return eax;
 241 }
 242 EXPORT_SYMBOL(tosh_smm);
 243
 244
 245 static long tosh_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 246 {
 247         SMMRegisters regs;
 248         SMMRegisters __user *argp = (SMMRegisters __user *)arg;
 249         unsigned short ax,bx;
 250         int err;
 251
 252         if (!argp)
 253                 return -EINVAL;
 254
 255         if (copy_from_user(&regs, argp, sizeof(SMMRegisters)))
 256                 return -EFAULT;
 257
 258         switch (cmd) {
 259                 case TOSH_SMM:
 260                         ax = regs.eax & 0xff00;
 261                         bx = regs.ebx & 0xffff;
 262                         /* block HCI calls to read/write memory & PCI devices */
 263                         if (((ax==0xff00) || (ax==0xfe00)) && (bx>0x0069))
 264                                 return -EINVAL;
 265
 266                         /* do we need to emulate the fan ? */
 267                         mutex_lock(&tosh_mutex);
 268                         if (tosh_fan==1) {
 269                                 if (((ax==0xf300) || (ax==0xf400)) && (bx==0x0004)) {
 270                                         err = tosh_emulate_fan(&regs);
 271                                         mutex_unlock(&tosh_mutex);
 272                                         break;
 273                                 }
 274                         }
 275                         err = tosh_smm(&regs);
 276                         mutex_unlock(&tosh_mutex);
 277                         break;
 278                 default:
 279                         return -EINVAL;
 280         }
 281
 282         if (copy_to_user(argp, &regs, sizeof(SMMRegisters)))
 283                 return -EFAULT;
 284
 285         return (err==0) ? 0:-EINVAL;
 286 }
 287
 288
 289 /*
 290  * Print the information for /proc/toshiba
 291  */
 292 #ifdef CONFIG_PROC_FS
 293 static int proc_toshiba_show(struct seq_file *m, void *v)
 294 {
 295         int key;
 296
 297         key = tosh_fn_status();
 298
 299         /* Arguments
 300              0) Linux driver version (this will change if format changes)
 301              1) Machine ID
 302              2) SCI version
 303              3) BIOS version (major, minor)
 304              4) BIOS date (in SCI date format)
 305              5) Fn Key status
 306         */
 307         seq_printf(m, "1.1 0x%04x %d.%d %d.%d 0x%04x 0x%02x\n",
 308                 tosh_id,
 309                 (tosh_sci & 0xff00)>>8,
 310                 tosh_sci & 0xff,
 311                 (tosh_bios & 0xff00)>>8,
 312                 tosh_bios & 0xff,
 313                 tosh_date,
 314                 key);
 315         return 0;
 316 }
 317 #endif
 318
 319
 320 /*
 321  * Determine which port to use for the Fn key status
 322  */
 323 static void tosh_set_fn_port(void)
 324 {
 325         switch (tosh_id) {
 326                 case 0xfc02: case 0xfc04: case 0xfc09: case 0xfc0a: case 0xfc10:
 327                 case 0xfc11: case 0xfc13: case 0xfc15: case 0xfc1a: case 0xfc1b:
 328                 case 0xfc5a:
 329                         tosh_fn = 0x62;
 330                         break;
 331                 case 0xfc08: case 0xfc17: case 0xfc1d: case 0xfcd1: case 0xfce0:
 332                 case 0xfce2:
 333                         tosh_fn = 0x68;
 334                         break;
 335                 default:
 336                         tosh_fn = 0x00;
 337                         break;
 338         }
 339
 340         return;
 341 }
 342
 343
 344 /*
 345  * Get the machine identification number of the current model
 346  */
 347 static int tosh_get_machine_id(void __iomem *bios)
 348 {
 349         int id;
 350         SMMRegisters regs;
 351         unsigned short bx,cx;
 352         unsigned long address;
 353
 354         id = (0x100*(int) readb(bios+0xfffe))+((int) readb(bios+0xfffa));
 355
 356         /* do we have a SCTTable machine identication number on our hands */
 357
 358         if (id==0xfc2f) {
 359
 360                 /* start by getting a pointer into the BIOS */
 361
 362                 regs.eax = 0xc000;
 363                 regs.ebx = 0x0000;
 364                 regs.ecx = 0x0000;
 365                 tosh_smm(&regs);
 366                 bx = (unsigned short) (regs.ebx & 0xffff);
 367
 368                 /* At this point in the Toshiba routines under MS Windows
 369                    the bx register holds 0xe6f5. However my code is producing
 370                    a different value! For the time being I will just fudge the
 371                    value. This has been verified on a Satellite Pro 430CDT,
 372                    Tecra 750CDT, Tecra 780DVD and Satellite 310CDT. */
 373 #if TOSH_DEBUG
 374                 pr_debug("toshiba: debugging ID ebx=0x%04x\n", regs.ebx);
 375 #endif
 376                 bx = 0xe6f5;
 377
 378                 /* now twiddle with our pointer a bit */
 379
 380                 address = bx;
 381                 cx = readw(bios + address);
 382                 address = 9+bx+cx;
 383                 cx = readw(bios + address);
 384                 address = 0xa+cx;
 385                 cx = readw(bios + address);
 386
 387                 /* now construct our machine identification number */
 388
 389                 id = ((cx & 0xff)<<8)+((cx & 0xff00)>>8);
 390         }
 391
 392         return id;
 393 }
 394
 395
 396 /*
 397  * Probe for the presence of a Toshiba laptop
 398  *
 399  *   returns and non-zero if unable to detect the presence of a Toshiba
 400  *   laptop, otherwise zero and determines the Machine ID, BIOS version and
 401  *   date, and SCI version.
 402  */
 403 static int tosh_probe(void)
 404 {
 405         int i,major,minor,day,year,month,flag;
 406         unsigned char signature[7] = { 0x54,0x4f,0x53,0x48,0x49,0x42,0x41 };
 407         SMMRegisters regs;
 408         void __iomem *bios = ioremap(0xf0000, 0x10000);
 409
 410         if (!bios)
 411                 return -ENOMEM;
 412
 413         /* extra sanity check for the string "TOSHIBA" in the BIOS because
 414            some machines that are not Toshiba's pass the next test */
 415
 416         for (i=0;i<7;i++) {
 417                 if (readb(bios+0xe010+i)!=signature[i]) {
 418                         pr_err("toshiba: not a supported Toshiba laptop\n");
 419                         iounmap(bios);
 420                         return -ENODEV;
 421                 }
 422         }
 423
 424         /* call the Toshiba SCI support check routine */
 425
 426         regs.eax = 0xf0f0;
 427         regs.ebx = 0x0000;
 428         regs.ecx = 0x0000;
 429         flag = tosh_smm(&regs);
 430
 431         /* if this is not a Toshiba laptop carry flag is set and ah=0x86 */
 432
 433         if ((flag==1) || ((regs.eax & 0xff00)==0x8600)) {
 434                 pr_err("toshiba: not a supported Toshiba laptop\n");
 435                 iounmap(bios);
 436                 return -ENODEV;
 437         }
 438
 439         /* if we get this far then we are running on a Toshiba (probably)! */
 440
 441         tosh_sci = regs.edx & 0xffff;
 442
 443         /* next get the machine ID of the current laptop */
 444
 445         tosh_id = tosh_get_machine_id(bios);
 446
 447         /* get the BIOS version */
 448
 449         major = readb(bios+0xe009)-'0';
 450         minor = ((readb(bios+0xe00b)-'0')*10)+(readb(bios+0xe00c)-'0');
 451         tosh_bios = (major*0x100)+minor;
 452
 453         /* get the BIOS date */
 454
 455         day = ((readb(bios+0xfff5)-'0')*10)+(readb(bios+0xfff6)-'0');
 456         month = ((readb(bios+0xfff8)-'0')*10)+(readb(bios+0xfff9)-'0');
 457         year = ((readb(bios+0xfffb)-'0')*10)+(readb(bios+0xfffc)-'0');
 458         tosh_date = (((year-90) & 0x1f)<<10) | ((month & 0xf)<<6)
 459                 | ((day & 0x1f)<<1);
 460
 461
 462         /* in theory we should check the ports we are going to use for the
 463            fn key detection (and the fan on the Portage 610/Tecra700), and
 464            then request them to stop other drivers using them. However as
 465            the keyboard driver grabs 0x60-0x6f and the pic driver grabs
 466            0xa0-0xbf we can't. We just have to live dangerously and use the
 467            ports anyway, oh boy! */
 468
 469         /* do we need to emulate the fan? */
 470
 471         if ((tosh_id==0xfccb) || (tosh_id==0xfccc))
 472                 tosh_fan = 1;
 473
 474         iounmap(bios);
 475
 476         return 0;
 477 }
 478
 479 static int __init toshiba_init(void)
 480 {
 481         int retval;
 482         /* are we running on a Toshiba laptop */
 483
 484         if (tosh_probe())
 485                 return -ENODEV;
 486
 487         pr_info("Toshiba System Management Mode driver v" TOSH_VERSION "\n");
 488
 489         /* set the port to use for Fn status if not specified as a parameter */
 490         if (tosh_fn==0x00)
 491                 tosh_set_fn_port();
 492
 493         /* register the device file */
 494         retval = misc_register(&tosh_device);
 495         if (retval < 0)
 496                 return retval;
 497
 498 #ifdef CONFIG_PROC_FS
 499         {
 500                 struct proc_dir_entry *pde;
 501
 502                 pde = proc_create_single("toshiba", 0, NULL, proc_toshiba_show);
 503                 if (!pde) {
 504                         misc_deregister(&tosh_device);
 505                         return -ENOMEM;
 506                 }
 507         }
 508 #endif
 509
 510         return 0;
 511 }
 512
 513 static void __exit toshiba_exit(void)
 514 {
 515         remove_proc_entry("toshiba", NULL);
 516         misc_deregister(&tosh_device);
 517 }
 518
 519 module_init(toshiba_init);
 520 module_exit(toshiba_exit);
 521