i8k.c 13.2 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593
/*
 * i8k.c -- Linux driver for accessing the SMM BIOS on Dell laptops.
 *	    See http://www.debian.org/~dz/i8k/ for more information
 *	    and for latest version of this driver.
 *
 * Copyright (C) 2001  Massimo Dal Zotto <dz@debian.org>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/dmi.h>
#include <linux/capability.h>
#include <asm/uaccess.h>
#include <asm/io.h>

#include <linux/i8k.h>

#define I8K_VERSION		"1.14 21/02/2005"

#define I8K_SMM_FN_STATUS	0x0025
#define I8K_SMM_POWER_STATUS	0x0069
#define I8K_SMM_SET_FAN		0x01a3
#define I8K_SMM_GET_FAN		0x00a3
#define I8K_SMM_GET_SPEED	0x02a3
#define I8K_SMM_GET_TEMP	0x10a3
#define I8K_SMM_GET_DELL_SIG1	0xfea3
#define I8K_SMM_GET_DELL_SIG2	0xffa3
#define I8K_SMM_BIOS_VERSION	0x00a6

#define I8K_FAN_MULT		30
#define I8K_MAX_TEMP		127

#define I8K_FN_NONE		0x00
#define I8K_FN_UP		0x01
#define I8K_FN_DOWN		0x02
#define I8K_FN_MUTE		0x04
#define I8K_FN_MASK		0x07
#define I8K_FN_SHIFT		8

#define I8K_POWER_AC		0x05
#define I8K_POWER_BATTERY	0x01

#define I8K_TEMPERATURE_BUG	1

static char bios_version[4];

MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
MODULE_LICENSE("GPL");

static int force;
module_param(force, bool, 0);
MODULE_PARM_DESC(force, "Force loading without checking for supported models");

static int ignore_dmi;
module_param(ignore_dmi, bool, 0);
MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");

static int restricted;
module_param(restricted, bool, 0);
MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");

static int power_status;
module_param(power_status, bool, 0600);
MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");

static int fan_mult = I8K_FAN_MULT;
module_param(fan_mult, int, 0);
MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with");

static int i8k_open_fs(struct inode *inode, struct file *file);
static int i8k_ioctl(struct inode *, struct file *, unsigned int,
		     unsigned long);

static const struct file_operations i8k_fops = {
	.owner		= THIS_MODULE,
	.open		= i8k_open_fs,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
	.ioctl		= i8k_ioctl,
};

struct smm_regs {
	unsigned int eax;
	unsigned int ebx __attribute__ ((packed));
	unsigned int ecx __attribute__ ((packed));
	unsigned int edx __attribute__ ((packed));
	unsigned int esi __attribute__ ((packed));
	unsigned int edi __attribute__ ((packed));
};

static inline const char *i8k_get_dmi_data(int field)
{
	const char *dmi_data = dmi_get_system_info(field);

	return dmi_data && *dmi_data ? dmi_data : "?";
}

/*
 * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
 */
static int i8k_smm(struct smm_regs *regs)
{
	int rc;
	int eax = regs->eax;

#if defined(CONFIG_X86_64)
	asm("pushq %%rax\n\t"
		"movl 0(%%rax),%%edx\n\t"
		"pushq %%rdx\n\t"
		"movl 4(%%rax),%%ebx\n\t"
		"movl 8(%%rax),%%ecx\n\t"
		"movl 12(%%rax),%%edx\n\t"
		"movl 16(%%rax),%%esi\n\t"
		"movl 20(%%rax),%%edi\n\t"
		"popq %%rax\n\t"
		"out %%al,$0xb2\n\t"
		"out %%al,$0x84\n\t"
		"xchgq %%rax,(%%rsp)\n\t"
		"movl %%ebx,4(%%rax)\n\t"
		"movl %%ecx,8(%%rax)\n\t"
		"movl %%edx,12(%%rax)\n\t"
		"movl %%esi,16(%%rax)\n\t"
		"movl %%edi,20(%%rax)\n\t"
		"popq %%rdx\n\t"
		"movl %%edx,0(%%rax)\n\t"
		"lahf\n\t"
		"shrl $8,%%eax\n\t"
		"andl $1,%%eax\n"
		:"=a"(rc)
		:    "a"(regs)
		:    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
#else
	asm("pushl %%eax\n\t"
	    "movl 0(%%eax),%%edx\n\t"
	    "push %%edx\n\t"
	    "movl 4(%%eax),%%ebx\n\t"
	    "movl 8(%%eax),%%ecx\n\t"
	    "movl 12(%%eax),%%edx\n\t"
	    "movl 16(%%eax),%%esi\n\t"
	    "movl 20(%%eax),%%edi\n\t"
	    "popl %%eax\n\t"
	    "out %%al,$0xb2\n\t"
	    "out %%al,$0x84\n\t"
	    "xchgl %%eax,(%%esp)\n\t"
	    "movl %%ebx,4(%%eax)\n\t"
	    "movl %%ecx,8(%%eax)\n\t"
	    "movl %%edx,12(%%eax)\n\t"
	    "movl %%esi,16(%%eax)\n\t"
	    "movl %%edi,20(%%eax)\n\t"
	    "popl %%edx\n\t"
	    "movl %%edx,0(%%eax)\n\t"
	    "lahf\n\t"
	    "shrl $8,%%eax\n\t"
	    "andl $1,%%eax\n":"=a"(rc)
	    :    "a"(regs)
	    :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
#endif
	if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
		return -EINVAL;

	return 0;
}

/*
 * Read the bios version. Return the version as an integer corresponding
 * to the ascii value, for example "A17" is returned as 0x00413137.
 */
static int i8k_get_bios_version(void)
{
	struct smm_regs regs = { .eax = I8K_SMM_BIOS_VERSION, };

	return i8k_smm(&regs) ? : regs.eax;
}

/*
 * Read the Fn key status.
 */
static int i8k_get_fn_status(void)
{
	struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
	int rc;

	if ((rc = i8k_smm(&regs)) < 0)
		return rc;

	switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
	case I8K_FN_UP:
		return I8K_VOL_UP;
	case I8K_FN_DOWN:
		return I8K_VOL_DOWN;
	case I8K_FN_MUTE:
		return I8K_VOL_MUTE;
	default:
		return 0;
	}
}

/*
 * Read the power status.
 */
static int i8k_get_power_status(void)
{
	struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
	int rc;

	if ((rc = i8k_smm(&regs)) < 0)
		return rc;

	return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
}

/*
 * Read the fan status.
 */
static int i8k_get_fan_status(int fan)
{
	struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };

	regs.ebx = fan & 0xff;
	return i8k_smm(&regs) ? : regs.eax & 0xff;
}

/*
 * Read the fan speed in RPM.
 */
static int i8k_get_fan_speed(int fan)
{
	struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };

	regs.ebx = fan & 0xff;
	return i8k_smm(&regs) ? : (regs.eax & 0xffff) * fan_mult;
}

/*
 * Set the fan speed (off, low, high). Returns the new fan status.
 */
static int i8k_set_fan(int fan, int speed)
{
	struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };

	speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed);
	regs.ebx = (fan & 0xff) | (speed << 8);

	return i8k_smm(&regs) ? : i8k_get_fan_status(fan);
}

/*
 * Read the cpu temperature.
 */
static int i8k_get_temp(int sensor)
{
	struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP, };
	int rc;
	int temp;

#ifdef I8K_TEMPERATURE_BUG
	static int prev;
#endif
	regs.ebx = sensor & 0xff;
	if ((rc = i8k_smm(&regs)) < 0)
		return rc;

	temp = regs.eax & 0xff;

#ifdef I8K_TEMPERATURE_BUG
	/*
	 * Sometimes the temperature sensor returns 0x99, which is out of range.
	 * In this case we return (once) the previous cached value. For example:
	 # 1003655137 00000058 00005a4b
	 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
	 # 1003655139 00000054 00005c52
	 */
	if (temp > I8K_MAX_TEMP) {
		temp = prev;
		prev = I8K_MAX_TEMP;
	} else {
		prev = temp;
	}
#endif

	return temp;
}

static int i8k_get_dell_signature(int req_fn)
{
	struct smm_regs regs = { .eax = req_fn, };
	int rc;

	if ((rc = i8k_smm(&regs)) < 0)
		return rc;

	return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
}

static int i8k_ioctl(struct inode *ip, struct file *fp, unsigned int cmd,
		     unsigned long arg)
{
	int val = 0;
	int speed;
	unsigned char buff[16];
	int __user *argp = (int __user *)arg;

	if (!argp)
		return -EINVAL;

	switch (cmd) {
	case I8K_BIOS_VERSION:
		val = i8k_get_bios_version();
		break;

	case I8K_MACHINE_ID:
		memset(buff, 0, 16);
		strlcpy(buff, i8k_get_dmi_data(DMI_PRODUCT_SERIAL), sizeof(buff));
		break;

	case I8K_FN_STATUS:
		val = i8k_get_fn_status();
		break;

	case I8K_POWER_STATUS:
		val = i8k_get_power_status();
		break;

	case I8K_GET_TEMP:
		val = i8k_get_temp(0);
		break;

	case I8K_GET_SPEED:
		if (copy_from_user(&val, argp, sizeof(int)))
			return -EFAULT;

		val = i8k_get_fan_speed(val);
		break;

	case I8K_GET_FAN:
		if (copy_from_user(&val, argp, sizeof(int)))
			return -EFAULT;

		val = i8k_get_fan_status(val);
		break;

	case I8K_SET_FAN:
		if (restricted && !capable(CAP_SYS_ADMIN))
			return -EPERM;

		if (copy_from_user(&val, argp, sizeof(int)))
			return -EFAULT;

		if (copy_from_user(&speed, argp + 1, sizeof(int)))
			return -EFAULT;

		val = i8k_set_fan(val, speed);
		break;

	default:
		return -EINVAL;
	}

	if (val < 0)
		return val;

	switch (cmd) {
	case I8K_BIOS_VERSION:
		if (copy_to_user(argp, &val, 4))
			return -EFAULT;

		break;
	case I8K_MACHINE_ID:
		if (copy_to_user(argp, buff, 16))
			return -EFAULT;

		break;
	default:
		if (copy_to_user(argp, &val, sizeof(int)))
			return -EFAULT;

		break;
	}

	return 0;
}

/*
 * Print the information for /proc/i8k.
 */
static int i8k_proc_show(struct seq_file *seq, void *offset)
{
	int fn_key, cpu_temp, ac_power;
	int left_fan, right_fan, left_speed, right_speed;

	cpu_temp	= i8k_get_temp(0);			/* 11100 µs */
	left_fan	= i8k_get_fan_status(I8K_FAN_LEFT);	/*   580 µs */
	right_fan	= i8k_get_fan_status(I8K_FAN_RIGHT);	/*   580 µs */
	left_speed	= i8k_get_fan_speed(I8K_FAN_LEFT);	/*   580 µs */
	right_speed	= i8k_get_fan_speed(I8K_FAN_RIGHT);	/*   580 µs */
	fn_key		= i8k_get_fn_status();			/*   750 µs */
	if (power_status)
		ac_power = i8k_get_power_status();		/* 14700 µs */
	else
		ac_power = -1;

	/*
	 * Info:
	 *
	 * 1)  Format version (this will change if format changes)
	 * 2)  BIOS version
	 * 3)  BIOS machine ID
	 * 4)  Cpu temperature
	 * 5)  Left fan status
	 * 6)  Right fan status
	 * 7)  Left fan speed
	 * 8)  Right fan speed
	 * 9)  AC power
	 * 10) Fn Key status
	 */
	return seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
			  I8K_PROC_FMT,
			  bios_version,
			  i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
			  cpu_temp,
			  left_fan, right_fan, left_speed, right_speed,
			  ac_power, fn_key);
}

static int i8k_open_fs(struct inode *inode, struct file *file)
{
	return single_open(file, i8k_proc_show, NULL);
}

static struct dmi_system_id __initdata i8k_dmi_table[] = {
	{
		.ident = "Dell Inspiron",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
		},
	},
	{
		.ident = "Dell Latitude",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
		},
	},
	{
		.ident = "Dell Inspiron 2",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
		},
	},
	{
		.ident = "Dell Latitude 2",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
		},
	},
	{	/* UK Inspiron 6400  */
		.ident = "Dell Inspiron 3",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
			DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
		},
	},
	{
		.ident = "Dell Inspiron 3",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
			DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
		},
	},
	{
		.ident = "Dell Precision",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
			DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
		},
	},
	{
		.ident = "Dell Vostro",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
			DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
		},
	},
        { }
};

/*
 * Probe for the presence of a supported laptop.
 */
static int __init i8k_probe(void)
{
	char buff[4];
	int version;

	/*
	 * Get DMI information
	 */
	if (!dmi_check_system(i8k_dmi_table)) {
		if (!ignore_dmi && !force)
			return -ENODEV;

		printk(KERN_INFO "i8k: not running on a supported Dell system.\n");
		printk(KERN_INFO "i8k: vendor=%s, model=%s, version=%s\n",
			i8k_get_dmi_data(DMI_SYS_VENDOR),
			i8k_get_dmi_data(DMI_PRODUCT_NAME),
			i8k_get_dmi_data(DMI_BIOS_VERSION));
	}

	strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION), sizeof(bios_version));

	/*
	 * Get SMM Dell signature
	 */
	if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
	    i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
		printk(KERN_ERR "i8k: unable to get SMM Dell signature\n");
		if (!force)
			return -ENODEV;
	}

	/*
	 * Get SMM BIOS version.
	 */
	version = i8k_get_bios_version();
	if (version <= 0) {
		printk(KERN_WARNING "i8k: unable to get SMM BIOS version\n");
	} else {
		buff[0] = (version >> 16) & 0xff;
		buff[1] = (version >> 8) & 0xff;
		buff[2] = (version) & 0xff;
		buff[3] = '\0';
		/*
		 * If DMI BIOS version is unknown use SMM BIOS version.
		 */
		if (!dmi_get_system_info(DMI_BIOS_VERSION))
			strlcpy(bios_version, buff, sizeof(bios_version));

		/*
		 * Check if the two versions match.
		 */
		if (strncmp(buff, bios_version, sizeof(bios_version)) != 0)
			printk(KERN_WARNING "i8k: BIOS version mismatch: %s != %s\n",
				buff, bios_version);
	}

	return 0;
}

static int __init i8k_init(void)
{
	struct proc_dir_entry *proc_i8k;

	/* Are we running on an supported laptop? */
	if (i8k_probe())
		return -ENODEV;

	/* Register the proc entry */
	proc_i8k = proc_create("i8k", 0, NULL, &i8k_fops);
	if (!proc_i8k)
		return -ENOENT;

	printk(KERN_INFO
	       "Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n",
	       I8K_VERSION);

	return 0;
}

static void __exit i8k_exit(void)
{
	remove_proc_entry("i8k", NULL);
}

module_init(i8k_init);
module_exit(i8k_exit);