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
  68 static DEFINE_MUTEX(tosh_mutex);
  69 static int tosh_fn;
  70 module_param_named(fn, tosh_fn, int, 0);
  71 MODULE_PARM_DESC(fn, "User specified Fn key detection port");
  72
  73 static int tosh_id;
  74 static int tosh_bios;
  75 static int tosh_date;
  76 static int tosh_sci;
  77 static int tosh_fan;
  78
  79 static long tosh_ioctl(struct file *, unsigned int,
  80         unsigned long);
  81
  82
  83 static const struct file_operations tosh_fops = {
  84         .owner          = THIS_MODULE,
  85         .unlocked_ioctl = tosh_ioctl,
  86         .llseek         = noop_llseek,
  87 };
  88
  89 static struct miscdevice tosh_device = {
  90         TOSH_MINOR_DEV,
  91         "toshiba",
  92         &tosh_fops
  93 };
  94
  95 /*
  96  * Read the Fn key status
  97  */
  98 #ifdef CONFIG_PROC_FS
  99 static int tosh_fn_status(void)
 100 {
 101         unsigned char scan;
 102         unsigned long flags;
 103
 104         if (tosh_fn!=0) {
 105                 scan = inb(tosh_fn);
 106         } else {
 107                 local_irq_save(flags);
 108                 outb(0x8e, 0xe4);
 109                 scan = inb(0xe5);
 110                 local_irq_restore(flags);
 111         }
 112
 113         return (int) scan;
 114 }
 115 #endif
 116
 117
 118 /*
 119  * For the Portage 610CT and the Tecra 700CS/700CDT emulate the HCI fan function
 120  */
 121 static int tosh_emulate_fan(SMMRegisters *regs)
 122 {
 123         unsigned long eax,ecx,flags;
 124         unsigned char al;
 125
 126         eax = regs->eax & 0xff00;
 127         ecx = regs->ecx & 0xffff;
 128
 129         /* Portage 610CT */
 130
 131         if (tosh_id==0xfccb) {
 132                 if (eax==0xfe00) {
 133                         /* fan status */
 134                         local_irq_save(flags);
 135                         outb(0xbe, 0xe4);
 136                         al = inb(0xe5);
 137                         local_irq_restore(flags);
 138                         regs->eax = 0x00;
 139                         regs->ecx = (unsigned int) (al & 0x01);
 140                 }
 141                 if ((eax==0xff00) && (ecx==0x0000)) {
 142                         /* fan off */
 143                         local_irq_save(flags);
 144                         outb(0xbe, 0xe4);
 145                         al = inb(0xe5);
 146                         outb(0xbe, 0xe4);
 147                         outb (al | 0x01, 0xe5);
 148                         local_irq_restore(flags);
 149                         regs->eax = 0x00;
 150                         regs->ecx = 0x00;
 151                 }
 152                 if ((eax==0xff00) && (ecx==0x0001)) {
 153                         /* fan on */
 154                         local_irq_save(flags);
 155                         outb(0xbe, 0xe4);
 156                         al = inb(0xe5);
 157                         outb(0xbe, 0xe4);
 158                         outb(al & 0xfe, 0xe5);
 159                         local_irq_restore(flags);
 160                         regs->eax = 0x00;
 161                         regs->ecx = 0x01;
 162                 }
 163         }
 164
 165         /* Tecra 700CS/CDT */
 166
 167         if (tosh_id==0xfccc) {
 168                 if (eax==0xfe00) {
 169                         /* fan status */
 170                         local_irq_save(flags);
 171                         outb(0xe0, 0xe4);
 172                         al = inb(0xe5);
 173                         local_irq_restore(flags);
 174                         regs->eax = 0x00;
 175                         regs->ecx = al & 0x01;
 176                 }
 177                 if ((eax==0xff00) && (ecx==0x0000)) {
 178                         /* fan off */
 179                         local_irq_save(flags);
 180                         outb(0xe0, 0xe4);
 181                         al = inb(0xe5);
 182                         outw(0xe0 | ((al & 0xfe) << 8), 0xe4);
 183                         local_irq_restore(flags);
 184                         regs->eax = 0x00;
 185                         regs->ecx = 0x00;
 186                 }
 187                 if ((eax==0xff00) && (ecx==0x0001)) {
 188                         /* fan on */
 189                         local_irq_save(flags);
 190                         outb(0xe0, 0xe4);
 191                         al = inb(0xe5);
 192                         outw(0xe0 | ((al | 0x01) << 8), 0xe4);
 193                         local_irq_restore(flags);
 194                         regs->eax = 0x00;
 195                         regs->ecx = 0x01;
 196                 }
 197         }
 198
 199         return 0;
 200 }
 201
 202
 203 /*
 204  * Put the laptop into System Management Mode
 205  */
 206 int tosh_smm(SMMRegisters *regs)
 207 {
 208         int eax;
 209
 210         asm ("# load the values into the registers\n\t" \
 211                 "pushl %%eax\n\t" \
 212                 "movl 0(%%eax),%%edx\n\t" \
 213                 "push %%edx\n\t" \
 214                 "movl 4(%%eax),%%ebx\n\t" \
 215                 "movl 8(%%eax),%%ecx\n\t" \
 216                 "movl 12(%%eax),%%edx\n\t" \
 217                 "movl 16(%%eax),%%esi\n\t" \
 218                 "movl 20(%%eax),%%edi\n\t" \
 219                 "popl %%eax\n\t" \
 220                 "# call the System Management mode\n\t" \
 221                 "inb $0xb2,%%al\n\t"
 222                 "# fill out the memory with the values in the registers\n\t" \
 223                 "xchgl %%eax,(%%esp)\n\t"
 224                 "movl %%ebx,4(%%eax)\n\t" \
 225                 "movl %%ecx,8(%%eax)\n\t" \
 226                 "movl %%edx,12(%%eax)\n\t" \
 227                 "movl %%esi,16(%%eax)\n\t" \
 228                 "movl %%edi,20(%%eax)\n\t" \
 229                 "popl %%edx\n\t" \
 230                 "movl %%edx,0(%%eax)\n\t" \
 231                 "# setup the return value to the carry flag\n\t" \
 232                 "lahf\n\t" \
 233                 "shrl $8,%%eax\n\t" \
 234                 "andl $1,%%eax\n" \
 235                 : "=a" (eax)
 236                 : "a" (regs)
 237                 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
 238
 239         return eax;
 240 }
 241 EXPORT_SYMBOL(tosh_smm);
 242
 243
 244 static long tosh_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 245 {
 246         SMMRegisters regs;
 247         SMMRegisters __user *argp = (SMMRegisters __user *)arg;
 248         unsigned short ax,bx;
 249         int err;
 250
 251         if (!argp)
 252                 return -EINVAL;
 253
 254         if (copy_from_user(&regs, argp, sizeof(SMMRegisters)))
 255                 return -EFAULT;
 256
 257         switch (cmd) {
 258                 case TOSH_SMM:
 259                         ax = regs.eax & 0xff00;
 260                         bx = regs.ebx & 0xffff;
 261                         /* block HCI calls to read/write memory & PCI devices */
 262                         if (((ax==0xff00) || (ax==0xfe00)) && (bx>0x0069))
 263                                 return -EINVAL;
 264
 265                         /* do we need to emulate the fan ? */
 266                         mutex_lock(&tosh_mutex);
 267                         if (tosh_fan==1) {
 268                                 if (((ax==0xf300) || (ax==0xf400)) && (bx==0x0004)) {
 269                                         err = tosh_emulate_fan(&regs);
 270                                         mutex_unlock(&tosh_mutex);
 271                                         break;
 272                                 }
 273                         }
 274                         err = tosh_smm(&regs);
 275                         mutex_unlock(&tosh_mutex);
 276                         break;
 277                 default:
 278                         return -EINVAL;
 279         }
 280
 281         if (copy_to_user(argp, &regs, sizeof(SMMRegisters)))
 282                 return -EFAULT;
 283
 284         return (err==0) ? 0:-EINVAL;
 285 }
 286
 287
 288 /*
 289  * Print the information for /proc/toshiba
 290  */
 291 #ifdef CONFIG_PROC_FS
 292 static int proc_toshiba_show(struct seq_file *m, void *v)
 293 {
 294         int key;
 295
 296         key = tosh_fn_status();
 297
 298         /* Arguments
 299              0) Linux driver version (this will change if format changes)
 300              1) Machine ID
 301              2) SCI version
 302              3) BIOS version (major, minor)
 303              4) BIOS date (in SCI date format)
 304              5) Fn Key status
 305         */
 306         seq_printf(m, "1.1 0x%04x %d.%d %d.%d 0x%04x 0x%02x\n",
 307                 tosh_id,
 308                 (tosh_sci & 0xff00)>>8,
 309                 tosh_sci & 0xff,
 310                 (tosh_bios & 0xff00)>>8,
 311                 tosh_bios & 0xff,
 312                 tosh_date,
 313                 key);
 314         return 0;
 315 }
 316 #endif
 317
 318
 319 /*
 320  * Determine which port to use for the Fn key status
 321  */
 322 static void tosh_set_fn_port(void)
 323 {
 324         switch (tosh_id) {
 325                 case 0xfc02: case 0xfc04: case 0xfc09: case 0xfc0a: case 0xfc10:
 326                 case 0xfc11: case 0xfc13: case 0xfc15: case 0xfc1a: case 0xfc1b:
 327                 case 0xfc5a:
 328                         tosh_fn = 0x62;
 329                         break;
 330                 case 0xfc08: case 0xfc17: case 0xfc1d: case 0xfcd1: case 0xfce0:
 331                 case 0xfce2:
 332                         tosh_fn = 0x68;
 333                         break;
 334                 default:
 335                         tosh_fn = 0x00;
 336                         break;
 337         }
 338
 339         return;
 340 }
 341
 342
 343 /*
 344  * Get the machine identification number of the current model
 345  */
 346 static int tosh_get_machine_id(void __iomem *bios)
 347 {
 348         int id;
 349         SMMRegisters regs;
 350         unsigned short bx,cx;
 351         unsigned long address;
 352
 353         id = (0x100*(int) readb(bios+0xfffe))+((int) readb(bios+0xfffa));
 354
 355         /* do we have a SCTTable machine identication number on our hands */
 356
 357         if (id==0xfc2f) {
 358
 359                 /* start by getting a pointer into the BIOS */
 360
 361                 regs.eax = 0xc000;
 362                 regs.ebx = 0x0000;
 363                 regs.ecx = 0x0000;
 364                 tosh_smm(&regs);
 365                 bx = (unsigned short) (regs.ebx & 0xffff);
 366
 367                 /* At this point in the Toshiba routines under MS Windows
 368                    the bx register holds 0xe6f5. However my code is producing
 369                    a different value! For the time being I will just fudge the
 370                    value. This has been verified on a Satellite Pro 430CDT,
 371                    Tecra 750CDT, Tecra 780DVD and Satellite 310CDT. */
 372 #if TOSH_DEBUG
 373                 pr_debug("toshiba: debugging ID ebx=0x%04x\n", regs.ebx);
 374 #endif
 375                 bx = 0xe6f5;
 376
 377                 /* now twiddle with our pointer a bit */
 378
 379                 address = bx;
 380                 cx = readw(bios + address);
 381                 address = 9+bx+cx;
 382                 cx = readw(bios + address);
 383                 address = 0xa+cx;
 384                 cx = readw(bios + address);
 385
 386                 /* now construct our machine identification number */
 387
 388                 id = ((cx & 0xff)<<8)+((cx & 0xff00)>>8);
 389         }
 390
 391         return id;
 392 }
 393
 394
 395 /*
 396  * Probe for the presence of a Toshiba laptop
 397  *
 398  *   returns and non-zero if unable to detect the presence of a Toshiba
 399  *   laptop, otherwise zero and determines the Machine ID, BIOS version and
 400  *   date, and SCI version.
 401  */
 402 static int tosh_probe(void)
 403 {
 404         int i,major,minor,day,year,month,flag;
 405         unsigned char signature[7] = { 0x54,0x4f,0x53,0x48,0x49,0x42,0x41 };
 406         SMMRegisters regs;
 407         void __iomem *bios = ioremap(0xf0000, 0x10000);
 408
 409         if (!bios)
 410                 return -ENOMEM;
 411
 412         /* extra sanity check for the string "TOSHIBA" in the BIOS because
 413            some machines that are not Toshiba's pass the next test */
 414
 415         for (i=0;i<7;i++) {
 416                 if (readb(bios+0xe010+i)!=signature[i]) {
 417                         pr_err("toshiba: not a supported Toshiba laptop\n");
 418                         iounmap(bios);
 419                         return -ENODEV;
 420                 }
 421         }
 422
 423         /* call the Toshiba SCI support check routine */
 424
 425         regs.eax = 0xf0f0;
 426         regs.ebx = 0x0000;
 427         regs.ecx = 0x0000;
 428         flag = tosh_smm(&regs);
 429
 430         /* if this is not a Toshiba laptop carry flag is set and ah=0x86 */
 431
 432         if ((flag==1) || ((regs.eax & 0xff00)==0x8600)) {
 433                 pr_err("toshiba: not a supported Toshiba laptop\n");
 434                 iounmap(bios);
 435                 return -ENODEV;
 436         }
 437
 438         /* if we get this far then we are running on a Toshiba (probably)! */
 439
 440         tosh_sci = regs.edx & 0xffff;
 441
 442         /* next get the machine ID of the current laptop */
 443
 444         tosh_id = tosh_get_machine_id(bios);
 445
 446         /* get the BIOS version */
 447
 448         major = readb(bios+0xe009)-'0';
 449         minor = ((readb(bios+0xe00b)-'0')*10)+(readb(bios+0xe00c)-'0');
 450         tosh_bios = (major*0x100)+minor;
 451
 452         /* get the BIOS date */
 453
 454         day = ((readb(bios+0xfff5)-'0')*10)+(readb(bios+0xfff6)-'0');
 455         month = ((readb(bios+0xfff8)-'0')*10)+(readb(bios+0xfff9)-'0');
 456         year = ((readb(bios+0xfffb)-'0')*10)+(readb(bios+0xfffc)-'0');
 457         tosh_date = (((year-90) & 0x1f)<<10) | ((month & 0xf)<<6)
 458                 | ((day & 0x1f)<<1);
 459
 460
 461         /* in theory we should check the ports we are going to use for the
 462            fn key detection (and the fan on the Portage 610/Tecra700), and
 463            then request them to stop other drivers using them. However as
 464            the keyboard driver grabs 0x60-0x6f and the pic driver grabs
 465            0xa0-0xbf we can't. We just have to live dangerously and use the
 466            ports anyway, oh boy! */
 467
 468         /* do we need to emulate the fan? */
 469
 470         if ((tosh_id==0xfccb) || (tosh_id==0xfccc))
 471                 tosh_fan = 1;
 472
 473         iounmap(bios);
 474
 475         return 0;
 476 }
 477
 478 static int __init toshiba_init(void)
 479 {
 480         int retval;
 481         /* are we running on a Toshiba laptop */
 482
 483         if (tosh_probe())
 484                 return -ENODEV;
 485
 486         pr_info("Toshiba System Management Mode driver v" TOSH_VERSION "\n");
 487
 488         /* set the port to use for Fn status if not specified as a parameter */
 489         if (tosh_fn==0x00)
 490                 tosh_set_fn_port();
 491
 492         /* register the device file */
 493         retval = misc_register(&tosh_device);
 494         if (retval < 0)
 495                 return retval;
 496
 497 #ifdef CONFIG_PROC_FS
 498         {
 499                 struct proc_dir_entry *pde;
 500
 501                 pde = proc_create_single("toshiba", 0, NULL, proc_toshiba_show);
 502                 if (!pde) {
 503                         misc_deregister(&tosh_device);
 504                         return -ENOMEM;
 505                 }
 506         }
 507 #endif
 508
 509         return 0;
 510 }
 511
 512 static void __exit toshiba_exit(void)
 513 {
 514         remove_proc_entry("toshiba", NULL);
 515         misc_deregister(&tosh_device);
 516 }
 517
 518 module_init(toshiba_init);
 519 module_exit(toshiba_exit);
 520