xref: /linux/drivers/char/toshiba.c (revision de6e0b198239857943db395377dc1d2ddd6c05df)
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 
522