drivers/char/toshiba.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /* toshiba.c -- Linux driver for accessing the SMM on Toshiba laptops
0003  *
0004  * Copyright (c) 1996-2001  Jonathan A. Buzzard (jonathan@buzzard.org.uk)
0005  *
0006  * Valuable assistance and patches from:
0007  *     Tom May <tom@you-bastards.com>
0008  *     Rob Napier <rnapier@employees.org>
0009  *
0010  * Fn status port numbers for machine ID's courtesy of
0011  *     0xfc02: Scott Eisert <scott.e@sky-eye.com>
0012  *     0xfc04: Steve VanDevender <stevev@efn.org>
0013  *     0xfc08: Garth Berry <garth@itsbruce.net>
0014  *     0xfc0a: Egbert Eich <eich@xfree86.org>
0015  *     0xfc10: Andrew Lofthouse <Andrew.Lofthouse@robins.af.mil>
0016  *     0xfc11: Spencer Olson <solson@novell.com>
0017  *     0xfc13: Claudius Frankewitz <kryp@gmx.de>
0018  *     0xfc15: Tom May <tom@you-bastards.com>
0019  *     0xfc17: Dave Konrad <konrad@xenia.it>
0020  *     0xfc1a: George Betzos <betzos@engr.colostate.edu>
0021  *     0xfc1b: Munemasa Wada <munemasa@jnovel.co.jp>
0022  *     0xfc1d: Arthur Liu <armie@slap.mine.nu>
0023  *     0xfc5a: Jacques L'helgoualc'h <lhh@free.fr>
0024  *     0xfcd1: Mr. Dave Konrad <konrad@xenia.it>
0025  *
0026  * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
0027  *
0028  *   This code is covered by the GNU GPL and you are free to make any
0029  *   changes you wish to it under the terms of the license. However the
0030  *   code has the potential to render your computer and/or someone else's
0031  *   unusable. Please proceed with care when modifying the code.
0032  *
0033  * Note: Unfortunately the laptop hardware can close the System Configuration
0034  *       Interface on it's own accord. It is therefore necessary for *all*
0035  *       programs using this driver to be aware that *any* SCI call can fail at
0036  *       *any* time. It is up to any program to be aware of this eventuality
0037  *       and take appropriate steps.
0038  *
0039  * The information used to write this driver has been obtained by reverse
0040  * engineering the software supplied by Toshiba for their portable computers in
0041  * strict accordance with the European Council Directive 92/250/EEC on the legal
0042  * protection of computer programs, and it's implementation into English Law by
0043  * the Copyright (Computer Programs) Regulations 1992 (S.I. 1992 No.3233).
0044  */
0045
0046 #define TOSH_VERSION "1.11 26/9/2001"
0047 #define TOSH_DEBUG 0
0048
0049 #include <linux/module.h>
0050 #include <linux/kernel.h>
0051 #include <linux/types.h>
0052 #include <linux/fcntl.h>
0053 #include <linux/miscdevice.h>
0054 #include <linux/ioport.h>
0055 #include <asm/io.h>
0056 #include <linux/uaccess.h>
0057 #include <linux/init.h>
0058 #include <linux/stat.h>
0059 #include <linux/proc_fs.h>
0060 #include <linux/seq_file.h>
0061 #include <linux/mutex.h>
0062 #include <linux/toshiba.h>
0063
0064 MODULE_LICENSE("GPL");
0065 MODULE_AUTHOR("Jonathan Buzzard <jonathan@buzzard.org.uk>");
0066 MODULE_DESCRIPTION("Toshiba laptop SMM driver");
0067
0068 static DEFINE_MUTEX(tosh_mutex);
0069 static int tosh_fn;
0070 module_param_named(fn, tosh_fn, int, 0);
0071 MODULE_PARM_DESC(fn, "User specified Fn key detection port");
0072
0073 static int tosh_id;
0074 static int tosh_bios;
0075 static int tosh_date;
0076 static int tosh_sci;
0077 static int tosh_fan;
0078
0079 static long tosh_ioctl(struct file *, unsigned int,
0080     unsigned long);
0081
0082
0083 static const struct file_operations tosh_fops = {
0084     .owner      = THIS_MODULE,
0085     .unlocked_ioctl = tosh_ioctl,
0086     .llseek     = noop_llseek,
0087 };
0088
0089 static struct miscdevice tosh_device = {
0090     TOSH_MINOR_DEV,
0091     "toshiba",
0092     &tosh_fops
0093 };
0094
0095 /*
0096  * Read the Fn key status
0097  */
0098 #ifdef CONFIG_PROC_FS
0099 static int tosh_fn_status(void)
0100 {
0101         unsigned char scan;
0102     unsigned long flags;
0103
0104     if (tosh_fn!=0) {
0105         scan = inb(tosh_fn);
0106     } else {
0107         local_irq_save(flags);
0108         outb(0x8e, 0xe4);
0109         scan = inb(0xe5);
0110         local_irq_restore(flags);
0111     }
0112
0113         return (int) scan;
0114 }
0115 #endif
0116
0117
0118 /*
0119  * For the Portage 610CT and the Tecra 700CS/700CDT emulate the HCI fan function
0120  */
0121 static int tosh_emulate_fan(SMMRegisters *regs)
0122 {
0123     unsigned long eax,ecx,flags;
0124     unsigned char al;
0125
0126     eax = regs->eax & 0xff00;
0127     ecx = regs->ecx & 0xffff;
0128
0129     /* Portage 610CT */
0130
0131     if (tosh_id==0xfccb) {
0132         if (eax==0xfe00) {
0133             /* fan status */
0134             local_irq_save(flags);
0135             outb(0xbe, 0xe4);
0136             al = inb(0xe5);
0137             local_irq_restore(flags);
0138             regs->eax = 0x00;
0139             regs->ecx = (unsigned int) (al & 0x01);
0140         }
0141         if ((eax==0xff00) && (ecx==0x0000)) {
0142             /* fan off */
0143             local_irq_save(flags);
0144             outb(0xbe, 0xe4);
0145             al = inb(0xe5);
0146             outb(0xbe, 0xe4);
0147             outb (al | 0x01, 0xe5);
0148             local_irq_restore(flags);
0149             regs->eax = 0x00;
0150             regs->ecx = 0x00;
0151         }
0152         if ((eax==0xff00) && (ecx==0x0001)) {
0153             /* fan on */
0154             local_irq_save(flags);
0155             outb(0xbe, 0xe4);
0156             al = inb(0xe5);
0157             outb(0xbe, 0xe4);
0158             outb(al & 0xfe, 0xe5);
0159             local_irq_restore(flags);
0160             regs->eax = 0x00;
0161             regs->ecx = 0x01;
0162         }
0163     }
0164
0165     /* Tecra 700CS/CDT */
0166
0167     if (tosh_id==0xfccc) {
0168         if (eax==0xfe00) {
0169             /* fan status */
0170             local_irq_save(flags);
0171             outb(0xe0, 0xe4);
0172             al = inb(0xe5);
0173             local_irq_restore(flags);
0174             regs->eax = 0x00;
0175             regs->ecx = al & 0x01;
0176         }
0177         if ((eax==0xff00) && (ecx==0x0000)) {
0178             /* fan off */
0179             local_irq_save(flags);
0180             outb(0xe0, 0xe4);
0181             al = inb(0xe5);
0182             outw(0xe0 | ((al & 0xfe) << 8), 0xe4);
0183             local_irq_restore(flags);
0184             regs->eax = 0x00;
0185             regs->ecx = 0x00;
0186         }
0187         if ((eax==0xff00) && (ecx==0x0001)) {
0188             /* fan on */
0189             local_irq_save(flags);
0190             outb(0xe0, 0xe4);
0191             al = inb(0xe5);
0192             outw(0xe0 | ((al | 0x01) << 8), 0xe4);
0193             local_irq_restore(flags);
0194             regs->eax = 0x00;
0195             regs->ecx = 0x01;
0196         }
0197     }
0198
0199     return 0;
0200 }
0201
0202
0203 /*
0204  * Put the laptop into System Management Mode
0205  */
0206 int tosh_smm(SMMRegisters *regs)
0207 {
0208     int eax;
0209
0210     asm ("# load the values into the registers\n\t" \
0211         "pushl %%eax\n\t" \
0212         "movl 0(%%eax),%%edx\n\t" \
0213         "push %%edx\n\t" \
0214         "movl 4(%%eax),%%ebx\n\t" \
0215         "movl 8(%%eax),%%ecx\n\t" \
0216         "movl 12(%%eax),%%edx\n\t" \
0217         "movl 16(%%eax),%%esi\n\t" \
0218         "movl 20(%%eax),%%edi\n\t" \
0219         "popl %%eax\n\t" \
0220         "# call the System Management mode\n\t" \
0221         "inb $0xb2,%%al\n\t"
0222         "# fill out the memory with the values in the registers\n\t" \
0223         "xchgl %%eax,(%%esp)\n\t"
0224         "movl %%ebx,4(%%eax)\n\t" \
0225         "movl %%ecx,8(%%eax)\n\t" \
0226         "movl %%edx,12(%%eax)\n\t" \
0227         "movl %%esi,16(%%eax)\n\t" \
0228         "movl %%edi,20(%%eax)\n\t" \
0229         "popl %%edx\n\t" \
0230         "movl %%edx,0(%%eax)\n\t" \
0231         "# setup the return value to the carry flag\n\t" \
0232         "lahf\n\t" \
0233         "shrl $8,%%eax\n\t" \
0234         "andl $1,%%eax\n" \
0235         : "=a" (eax)
0236         : "a" (regs)
0237         : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
0238
0239     return eax;
0240 }
0241 EXPORT_SYMBOL(tosh_smm);
0242
0243
0244 static long tosh_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
0245 {
0246     SMMRegisters regs;
0247     SMMRegisters __user *argp = (SMMRegisters __user *)arg;
0248     unsigned short ax,bx;
0249     int err;
0250
0251     if (!argp)
0252         return -EINVAL;
0253
0254     if (copy_from_user(&regs, argp, sizeof(SMMRegisters)))
0255         return -EFAULT;
0256
0257     switch (cmd) {
0258         case TOSH_SMM:
0259             ax = regs.eax & 0xff00;
0260             bx = regs.ebx & 0xffff;
0261             /* block HCI calls to read/write memory & PCI devices */
0262             if (((ax==0xff00) || (ax==0xfe00)) && (bx>0x0069))
0263                 return -EINVAL;
0264
0265             /* do we need to emulate the fan ? */
0266             mutex_lock(&tosh_mutex);
0267             if (tosh_fan==1) {
0268                 if (((ax==0xf300) || (ax==0xf400)) && (bx==0x0004)) {
0269                     err = tosh_emulate_fan(&regs);
0270                     mutex_unlock(&tosh_mutex);
0271                     break;
0272                 }
0273             }
0274             err = tosh_smm(&regs);
0275             mutex_unlock(&tosh_mutex);
0276             break;
0277         default:
0278             return -EINVAL;
0279     }
0280
0281         if (copy_to_user(argp, &regs, sizeof(SMMRegisters)))
0282             return -EFAULT;
0283
0284     return (err==0) ? 0:-EINVAL;
0285 }
0286
0287
0288 /*
0289  * Print the information for /proc/toshiba
0290  */
0291 #ifdef CONFIG_PROC_FS
0292 static int proc_toshiba_show(struct seq_file *m, void *v)
0293 {
0294     int key;
0295
0296     key = tosh_fn_status();
0297
0298     /* Arguments
0299          0) Linux driver version (this will change if format changes)
0300          1) Machine ID
0301          2) SCI version
0302          3) BIOS version (major, minor)
0303          4) BIOS date (in SCI date format)
0304          5) Fn Key status
0305     */
0306     seq_printf(m, "1.1 0x%04x %d.%d %d.%d 0x%04x 0x%02x\n",
0307         tosh_id,
0308         (tosh_sci & 0xff00)>>8,
0309         tosh_sci & 0xff,
0310         (tosh_bios & 0xff00)>>8,
0311         tosh_bios & 0xff,
0312         tosh_date,
0313         key);
0314     return 0;
0315 }
0316 #endif
0317
0318
0319 /*
0320  * Determine which port to use for the Fn key status
0321  */
0322 static void tosh_set_fn_port(void)
0323 {
0324     switch (tosh_id) {
0325         case 0xfc02: case 0xfc04: case 0xfc09: case 0xfc0a: case 0xfc10:
0326         case 0xfc11: case 0xfc13: case 0xfc15: case 0xfc1a: case 0xfc1b:
0327         case 0xfc5a:
0328             tosh_fn = 0x62;
0329             break;
0330         case 0xfc08: case 0xfc17: case 0xfc1d: case 0xfcd1: case 0xfce0:
0331         case 0xfce2:
0332             tosh_fn = 0x68;
0333             break;
0334         default:
0335             tosh_fn = 0x00;
0336             break;
0337     }
0338
0339     return;
0340 }
0341
0342
0343 /*
0344  * Get the machine identification number of the current model
0345  */
0346 static int tosh_get_machine_id(void __iomem *bios)
0347 {
0348     int id;
0349     SMMRegisters regs;
0350     unsigned short bx,cx;
0351     unsigned long address;
0352
0353     id = (0x100*(int) readb(bios+0xfffe))+((int) readb(bios+0xfffa));
0354
0355     /* do we have a SCTTable machine identication number on our hands */
0356
0357     if (id==0xfc2f) {
0358
0359         /* start by getting a pointer into the BIOS */
0360
0361         regs.eax = 0xc000;
0362         regs.ebx = 0x0000;
0363         regs.ecx = 0x0000;
0364         tosh_smm(&regs);
0365         bx = (unsigned short) (regs.ebx & 0xffff);
0366
0367         /* At this point in the Toshiba routines under MS Windows
0368            the bx register holds 0xe6f5. However my code is producing
0369            a different value! For the time being I will just fudge the
0370            value. This has been verified on a Satellite Pro 430CDT,
0371            Tecra 750CDT, Tecra 780DVD and Satellite 310CDT. */
0372 #if TOSH_DEBUG
0373         pr_debug("toshiba: debugging ID ebx=0x%04x\n", regs.ebx);
0374 #endif
0375         bx = 0xe6f5;
0376
0377         /* now twiddle with our pointer a bit */
0378
0379         address = bx;
0380         cx = readw(bios + address);
0381         address = 9+bx+cx;
0382         cx = readw(bios + address);
0383         address = 0xa+cx;
0384         cx = readw(bios + address);
0385
0386         /* now construct our machine identification number */
0387
0388         id = ((cx & 0xff)<<8)+((cx & 0xff00)>>8);
0389     }
0390
0391     return id;
0392 }
0393
0394
0395 /*
0396  * Probe for the presence of a Toshiba laptop
0397  *
0398  *   returns and non-zero if unable to detect the presence of a Toshiba
0399  *   laptop, otherwise zero and determines the Machine ID, BIOS version and
0400  *   date, and SCI version.
0401  */
0402 static int tosh_probe(void)
0403 {
0404     int i,major,minor,day,year,month,flag;
0405     unsigned char signature[7] = { 0x54,0x4f,0x53,0x48,0x49,0x42,0x41 };
0406     SMMRegisters regs;
0407     void __iomem *bios = ioremap(0xf0000, 0x10000);
0408
0409     if (!bios)
0410         return -ENOMEM;
0411
0412     /* extra sanity check for the string "TOSHIBA" in the BIOS because
0413        some machines that are not Toshiba's pass the next test */
0414
0415     for (i=0;i<7;i++) {
0416         if (readb(bios+0xe010+i)!=signature[i]) {
0417             pr_err("toshiba: not a supported Toshiba laptop\n");
0418             iounmap(bios);
0419             return -ENODEV;
0420         }
0421     }
0422
0423     /* call the Toshiba SCI support check routine */
0424
0425     regs.eax = 0xf0f0;
0426     regs.ebx = 0x0000;
0427     regs.ecx = 0x0000;
0428     flag = tosh_smm(&regs);
0429
0430     /* if this is not a Toshiba laptop carry flag is set and ah=0x86 */
0431
0432     if ((flag==1) || ((regs.eax & 0xff00)==0x8600)) {
0433         pr_err("toshiba: not a supported Toshiba laptop\n");
0434         iounmap(bios);
0435         return -ENODEV;
0436     }
0437
0438     /* if we get this far then we are running on a Toshiba (probably)! */
0439
0440     tosh_sci = regs.edx & 0xffff;
0441
0442     /* next get the machine ID of the current laptop */
0443
0444     tosh_id = tosh_get_machine_id(bios);
0445
0446     /* get the BIOS version */
0447
0448     major = readb(bios+0xe009)-'0';
0449     minor = ((readb(bios+0xe00b)-'0')*10)+(readb(bios+0xe00c)-'0');
0450     tosh_bios = (major*0x100)+minor;
0451
0452     /* get the BIOS date */
0453
0454     day = ((readb(bios+0xfff5)-'0')*10)+(readb(bios+0xfff6)-'0');
0455     month = ((readb(bios+0xfff8)-'0')*10)+(readb(bios+0xfff9)-'0');
0456     year = ((readb(bios+0xfffb)-'0')*10)+(readb(bios+0xfffc)-'0');
0457     tosh_date = (((year-90) & 0x1f)<<10) | ((month & 0xf)<<6)
0458         | ((day & 0x1f)<<1);
0459
0460
0461     /* in theory we should check the ports we are going to use for the
0462        fn key detection (and the fan on the Portage 610/Tecra700), and
0463        then request them to stop other drivers using them. However as
0464        the keyboard driver grabs 0x60-0x6f and the pic driver grabs
0465        0xa0-0xbf we can't. We just have to live dangerously and use the
0466        ports anyway, oh boy! */
0467
0468     /* do we need to emulate the fan? */
0469
0470     if ((tosh_id==0xfccb) || (tosh_id==0xfccc))
0471         tosh_fan = 1;
0472
0473     iounmap(bios);
0474
0475     return 0;
0476 }
0477
0478 static int __init toshiba_init(void)
0479 {
0480     int retval;
0481     /* are we running on a Toshiba laptop */
0482
0483     if (tosh_probe())
0484         return -ENODEV;
0485
0486     pr_info("Toshiba System Management Mode driver v" TOSH_VERSION "\n");
0487
0488     /* set the port to use for Fn status if not specified as a parameter */
0489     if (tosh_fn==0x00)
0490         tosh_set_fn_port();
0491
0492     /* register the device file */
0493     retval = misc_register(&tosh_device);
0494     if (retval < 0)
0495         return retval;
0496
0497 #ifdef CONFIG_PROC_FS
0498     {
0499         struct proc_dir_entry *pde;
0500
0501         pde = proc_create_single("toshiba", 0, NULL, proc_toshiba_show);
0502         if (!pde) {
0503             misc_deregister(&tosh_device);
0504             return -ENOMEM;
0505         }
0506     }
0507 #endif
0508
0509     return 0;
0510 }
0511
0512 static void __exit toshiba_exit(void)
0513 {
0514     remove_proc_entry("toshiba", NULL);
0515     misc_deregister(&tosh_device);
0516 }
0517
0518 module_init(toshiba_init);
0519 module_exit(toshiba_exit);
0520