xref: /openbmc/linux/drivers/char/toshiba.c (revision 2cf1c348)
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 
521