xref: /openbmc/linux/drivers/char/toshiba.c (revision 6c33a6f4)
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 		pr_debug("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 			pr_err("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 		pr_err("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 	pr_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 
524