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 #define TOSH_MINOR_DEV 181
  65
  66 MODULE_LICENSE("GPL");
  67 MODULE_AUTHOR("Jonathan Buzzard <jonathan@buzzard.org.uk>");
  68 MODULE_DESCRIPTION("Toshiba laptop SMM driver");
  69 MODULE_SUPPORTED_DEVICE("toshiba");
  70
  71 static DEFINE_MUTEX(tosh_mutex);
  72 static int tosh_fn;
  73 module_param_named(fn, tosh_fn, int, 0);
  74 MODULE_PARM_DESC(fn, "User specified Fn key detection port");
  75
  76 static int tosh_id;
  77 static int tosh_bios;
  78 static int tosh_date;
  79 static int tosh_sci;
  80 static int tosh_fan;
  81
  82 static long tosh_ioctl(struct file *, unsigned int,
  83         unsigned long);
  84
  85
  86 static const struct file_operations tosh_fops = {
  87         .owner          = THIS_MODULE,
  88         .unlocked_ioctl = tosh_ioctl,
  89         .llseek         = noop_llseek,
  90 };
  91
  92 static struct miscdevice tosh_device = {
  93         TOSH_MINOR_DEV,
  94         "toshiba",
  95         &tosh_fops
  96 };
  97
  98 /*
  99  * Read the Fn key status
 100  */
 101 #ifdef CONFIG_PROC_FS
 102 static int tosh_fn_status(void)
 103 {
 104         unsigned char scan;
 105         unsigned long flags;
 106
 107         if (tosh_fn!=0) {
 108                 scan = inb(tosh_fn);
 109         } else {
 110                 local_irq_save(flags);
 111                 outb(0x8e, 0xe4);
 112                 scan = inb(0xe5);
 113                 local_irq_restore(flags);
 114         }
 115
 116         return (int) scan;
 117 }
 118 #endif
 119
 120
 121 /*
 122  * For the Portage 610CT and the Tecra 700CS/700CDT emulate the HCI fan function
 123  */
 124 static int tosh_emulate_fan(SMMRegisters *regs)
 125 {
 126         unsigned long eax,ecx,flags;
 127         unsigned char al;
 128
 129         eax = regs->eax & 0xff00;
 130         ecx = regs->ecx & 0xffff;
 131
 132         /* Portage 610CT */
 133
 134         if (tosh_id==0xfccb) {
 135                 if (eax==0xfe00) {
 136                         /* fan status */
 137                         local_irq_save(flags);
 138                         outb(0xbe, 0xe4);
 139                         al = inb(0xe5);
 140                         local_irq_restore(flags);
 141                         regs->eax = 0x00;
 142                         regs->ecx = (unsigned int) (al & 0x01);
 143                 }
 144                 if ((eax==0xff00) && (ecx==0x0000)) {
 145                         /* fan off */
 146                         local_irq_save(flags);
 147                         outb(0xbe, 0xe4);
 148                         al = inb(0xe5);
 149                         outb(0xbe, 0xe4);
 150                         outb (al | 0x01, 0xe5);
 151                         local_irq_restore(flags);
 152                         regs->eax = 0x00;
 153                         regs->ecx = 0x00;
 154                 }
 155                 if ((eax==0xff00) && (ecx==0x0001)) {
 156                         /* fan on */
 157                         local_irq_save(flags);
 158                         outb(0xbe, 0xe4);
 159                         al = inb(0xe5);
 160                         outb(0xbe, 0xe4);
 161                         outb(al & 0xfe, 0xe5);
 162                         local_irq_restore(flags);
 163                         regs->eax = 0x00;
 164                         regs->ecx = 0x01;
 165                 }
 166         }
 167
 168         /* Tecra 700CS/CDT */
 169
 170         if (tosh_id==0xfccc) {
 171                 if (eax==0xfe00) {
 172                         /* fan status */
 173                         local_irq_save(flags);
 174                         outb(0xe0, 0xe4);
 175                         al = inb(0xe5);
 176                         local_irq_restore(flags);
 177                         regs->eax = 0x00;
 178                         regs->ecx = al & 0x01;
 179                 }
 180                 if ((eax==0xff00) && (ecx==0x0000)) {
 181                         /* fan off */
 182                         local_irq_save(flags);
 183                         outb(0xe0, 0xe4);
 184                         al = inb(0xe5);
 185                         outw(0xe0 | ((al & 0xfe) << 8), 0xe4);
 186                         local_irq_restore(flags);
 187                         regs->eax = 0x00;
 188                         regs->ecx = 0x00;
 189                 }
 190                 if ((eax==0xff00) && (ecx==0x0001)) {
 191                         /* fan on */
 192                         local_irq_save(flags);
 193                         outb(0xe0, 0xe4);
 194                         al = inb(0xe5);
 195                         outw(0xe0 | ((al | 0x01) << 8), 0xe4);
 196                         local_irq_restore(flags);
 197                         regs->eax = 0x00;
 198                         regs->ecx = 0x01;
 199                 }
 200         }
 201
 202         return 0;
 203 }
 204
 205
 206 /*
 207  * Put the laptop into System Management Mode
 208  */
 209 int tosh_smm(SMMRegisters *regs)
 210 {
 211         int eax;
 212
 213         asm ("# load the values into the registers\n\t" \
 214                 "pushl %%eax\n\t" \
 215                 "movl 0(%%eax),%%edx\n\t" \
 216                 "push %%edx\n\t" \
 217                 "movl 4(%%eax),%%ebx\n\t" \
 218                 "movl 8(%%eax),%%ecx\n\t" \
 219                 "movl 12(%%eax),%%edx\n\t" \
 220                 "movl 16(%%eax),%%esi\n\t" \
 221                 "movl 20(%%eax),%%edi\n\t" \
 222                 "popl %%eax\n\t" \
 223                 "# call the System Management mode\n\t" \
 224                 "inb $0xb2,%%al\n\t"
 225                 "# fill out the memory with the values in the registers\n\t" \
 226                 "xchgl %%eax,(%%esp)\n\t"
 227                 "movl %%ebx,4(%%eax)\n\t" \
 228                 "movl %%ecx,8(%%eax)\n\t" \
 229                 "movl %%edx,12(%%eax)\n\t" \
 230                 "movl %%esi,16(%%eax)\n\t" \
 231                 "movl %%edi,20(%%eax)\n\t" \
 232                 "popl %%edx\n\t" \
 233                 "movl %%edx,0(%%eax)\n\t" \
 234                 "# setup the return value to the carry flag\n\t" \
 235                 "lahf\n\t" \
 236                 "shrl $8,%%eax\n\t" \
 237                 "andl $1,%%eax\n" \
 238                 : "=a" (eax)
 239                 : "a" (regs)
 240                 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
 241
 242         return eax;
 243 }
 244 EXPORT_SYMBOL(tosh_smm);
 245
 246
 247 static long tosh_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 248 {
 249         SMMRegisters regs;
 250         SMMRegisters __user *argp = (SMMRegisters __user *)arg;
 251         unsigned short ax,bx;
 252         int err;
 253
 254         if (!argp)
 255                 return -EINVAL;
 256
 257         if (copy_from_user(&regs, argp, sizeof(SMMRegisters)))
 258                 return -EFAULT;
 259
 260         switch (cmd) {
 261                 case TOSH_SMM:
 262                         ax = regs.eax & 0xff00;
 263                         bx = regs.ebx & 0xffff;
 264                         /* block HCI calls to read/write memory & PCI devices */
 265                         if (((ax==0xff00) || (ax==0xfe00)) && (bx>0x0069))
 266                                 return -EINVAL;
 267
 268                         /* do we need to emulate the fan ? */
 269                         mutex_lock(&tosh_mutex);
 270                         if (tosh_fan==1) {
 271                                 if (((ax==0xf300) || (ax==0xf400)) && (bx==0x0004)) {
 272                                         err = tosh_emulate_fan(&regs);
 273                                         mutex_unlock(&tosh_mutex);
 274                                         break;
 275                                 }
 276                         }
 277                         err = tosh_smm(&regs);
 278                         mutex_unlock(&tosh_mutex);
 279                         break;
 280                 default:
 281                         return -EINVAL;
 282         }
 283
 284         if (copy_to_user(argp, &regs, sizeof(SMMRegisters)))
 285                 return -EFAULT;
 286
 287         return (err==0) ? 0:-EINVAL;
 288 }
 289
 290
 291 /*
 292  * Print the information for /proc/toshiba
 293  */
 294 #ifdef CONFIG_PROC_FS
 295 static int proc_toshiba_show(struct seq_file *m, void *v)
 296 {
 297         int key;
 298
 299         key = tosh_fn_status();
 300
 301         /* Arguments
 302              0) Linux driver version (this will change if format changes)
 303              1) Machine ID
 304              2) SCI version
 305              3) BIOS version (major, minor)
 306              4) BIOS date (in SCI date format)
 307              5) Fn Key status
 308         */
 309         seq_printf(m, "1.1 0x%04x %d.%d %d.%d 0x%04x 0x%02x\n",
 310                 tosh_id,
 311                 (tosh_sci & 0xff00)>>8,
 312                 tosh_sci & 0xff,
 313                 (tosh_bios & 0xff00)>>8,
 314                 tosh_bios & 0xff,
 315                 tosh_date,
 316                 key);
 317         return 0;
 318 }
 319 #endif
 320
 321
 322 /*
 323  * Determine which port to use for the Fn key status
 324  */
 325 static void tosh_set_fn_port(void)
 326 {
 327         switch (tosh_id) {
 328                 case 0xfc02: case 0xfc04: case 0xfc09: case 0xfc0a: case 0xfc10:
 329                 case 0xfc11: case 0xfc13: case 0xfc15: case 0xfc1a: case 0xfc1b:
 330                 case 0xfc5a:
 331                         tosh_fn = 0x62;
 332                         break;
 333                 case 0xfc08: case 0xfc17: case 0xfc1d: case 0xfcd1: case 0xfce0:
 334                 case 0xfce2:
 335                         tosh_fn = 0x68;
 336                         break;
 337                 default:
 338                         tosh_fn = 0x00;
 339                         break;
 340         }
 341
 342         return;
 343 }
 344
 345
 346 /*
 347  * Get the machine identification number of the current model
 348  */
 349 static int tosh_get_machine_id(void __iomem *bios)
 350 {
 351         int id;
 352         SMMRegisters regs;
 353         unsigned short bx,cx;
 354         unsigned long address;
 355
 356         id = (0x100*(int) readb(bios+0xfffe))+((int) readb(bios+0xfffa));
 357
 358         /* do we have a SCTTable machine identication number on our hands */
 359
 360         if (id==0xfc2f) {
 361
 362                 /* start by getting a pointer into the BIOS */
 363
 364                 regs.eax = 0xc000;
 365                 regs.ebx = 0x0000;
 366                 regs.ecx = 0x0000;
 367                 tosh_smm(&regs);
 368                 bx = (unsigned short) (regs.ebx & 0xffff);
 369
 370                 /* At this point in the Toshiba routines under MS Windows
 371                    the bx register holds 0xe6f5. However my code is producing
 372                    a different value! For the time being I will just fudge the
 373                    value. This has been verified on a Satellite Pro 430CDT,
 374                    Tecra 750CDT, Tecra 780DVD and Satellite 310CDT. */
 375 #if TOSH_DEBUG
 376                 printk("toshiba: debugging ID ebx=0x%04x\n", regs.ebx);
 377 #endif
 378                 bx = 0xe6f5;
 379
 380                 /* now twiddle with our pointer a bit */
 381
 382                 address = bx;
 383                 cx = readw(bios + address);
 384                 address = 9+bx+cx;
 385                 cx = readw(bios + address);
 386                 address = 0xa+cx;
 387                 cx = readw(bios + address);
 388
 389                 /* now construct our machine identification number */
 390
 391                 id = ((cx & 0xff)<<8)+((cx & 0xff00)>>8);
 392         }
 393
 394         return id;
 395 }
 396
 397
 398 /*
 399  * Probe for the presence of a Toshiba laptop
 400  *
 401  *   returns and non-zero if unable to detect the presence of a Toshiba
 402  *   laptop, otherwise zero and determines the Machine ID, BIOS version and
 403  *   date, and SCI version.
 404  */
 405 static int tosh_probe(void)
 406 {
 407         int i,major,minor,day,year,month,flag;
 408         unsigned char signature[7] = { 0x54,0x4f,0x53,0x48,0x49,0x42,0x41 };
 409         SMMRegisters regs;
 410         void __iomem *bios = ioremap(0xf0000, 0x10000);
 411
 412         if (!bios)
 413                 return -ENOMEM;
 414
 415         /* extra sanity check for the string "TOSHIBA" in the BIOS because
 416            some machines that are not Toshiba's pass the next test */
 417
 418         for (i=0;i<7;i++) {
 419                 if (readb(bios+0xe010+i)!=signature[i]) {
 420                         printk("toshiba: not a supported Toshiba laptop\n");
 421                         iounmap(bios);
 422                         return -ENODEV;
 423                 }
 424         }
 425
 426         /* call the Toshiba SCI support check routine */
 427
 428         regs.eax = 0xf0f0;
 429         regs.ebx = 0x0000;
 430         regs.ecx = 0x0000;
 431         flag = tosh_smm(&regs);
 432
 433         /* if this is not a Toshiba laptop carry flag is set and ah=0x86 */
 434
 435         if ((flag==1) || ((regs.eax & 0xff00)==0x8600)) {
 436                 printk("toshiba: not a supported Toshiba laptop\n");
 437                 iounmap(bios);
 438                 return -ENODEV;
 439         }
 440
 441         /* if we get this far then we are running on a Toshiba (probably)! */
 442
 443         tosh_sci = regs.edx & 0xffff;
 444
 445         /* next get the machine ID of the current laptop */
 446
 447         tosh_id = tosh_get_machine_id(bios);
 448
 449         /* get the BIOS version */
 450
 451         major = readb(bios+0xe009)-'0';
 452         minor = ((readb(bios+0xe00b)-'0')*10)+(readb(bios+0xe00c)-'0');
 453         tosh_bios = (major*0x100)+minor;
 454
 455         /* get the BIOS date */
 456
 457         day = ((readb(bios+0xfff5)-'0')*10)+(readb(bios+0xfff6)-'0');
 458         month = ((readb(bios+0xfff8)-'0')*10)+(readb(bios+0xfff9)-'0');
 459         year = ((readb(bios+0xfffb)-'0')*10)+(readb(bios+0xfffc)-'0');
 460         tosh_date = (((year-90) & 0x1f)<<10) | ((month & 0xf)<<6)
 461                 | ((day & 0x1f)<<1);
 462
 463
 464         /* in theory we should check the ports we are going to use for the
 465            fn key detection (and the fan on the Portage 610/Tecra700), and
 466            then request them to stop other drivers using them. However as
 467            the keyboard driver grabs 0x60-0x6f and the pic driver grabs
 468            0xa0-0xbf we can't. We just have to live dangerously and use the
 469            ports anyway, oh boy! */
 470
 471         /* do we need to emulate the fan? */
 472
 473         if ((tosh_id==0xfccb) || (tosh_id==0xfccc))
 474                 tosh_fan = 1;
 475
 476         iounmap(bios);
 477
 478         return 0;
 479 }
 480
 481 static int __init toshiba_init(void)
 482 {
 483         int retval;
 484         /* are we running on a Toshiba laptop */
 485
 486         if (tosh_probe())
 487                 return -ENODEV;
 488
 489         printk(KERN_INFO "Toshiba System Management Mode driver v" TOSH_VERSION "\n");
 490
 491         /* set the port to use for Fn status if not specified as a parameter */
 492         if (tosh_fn==0x00)
 493                 tosh_set_fn_port();
 494
 495         /* register the device file */
 496         retval = misc_register(&tosh_device);
 497         if (retval < 0)
 498                 return retval;
 499
 500 #ifdef CONFIG_PROC_FS
 501         {
 502                 struct proc_dir_entry *pde;
 503
 504                 pde = proc_create_single("toshiba", 0, NULL, proc_toshiba_show);
 505                 if (!pde) {
 506                         misc_deregister(&tosh_device);
 507                         return -ENOMEM;
 508                 }
 509         }
 510 #endif
 511
 512         return 0;
 513 }
 514
 515 static void __exit toshiba_exit(void)
 516 {
 517         remove_proc_entry("toshiba", NULL);
 518         misc_deregister(&tosh_device);
 519 }
 520
 521 module_init(toshiba_init);
 522 module_exit(toshiba_exit);
 523