1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * dell-smm-hwmon.c -- Linux driver for accessing the SMM BIOS on Dell laptops.
4  *
5  * Copyright (C) 2001  Massimo Dal Zotto <dz@debian.org>
6  *
7  * Hwmon integration:
8  * Copyright (C) 2011  Jean Delvare <jdelvare@suse.de>
9  * Copyright (C) 2013, 2014  Guenter Roeck <linux@roeck-us.net>
10  * Copyright (C) 2014, 2015  Pali Rohár <pali@kernel.org>
11  */
12 
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <linux/capability.h>
16 #include <linux/cpu.h>
17 #include <linux/ctype.h>
18 #include <linux/delay.h>
19 #include <linux/dmi.h>
20 #include <linux/err.h>
21 #include <linux/errno.h>
22 #include <linux/hwmon.h>
23 #include <linux/init.h>
24 #include <linux/module.h>
25 #include <linux/mutex.h>
26 #include <linux/platform_device.h>
27 #include <linux/proc_fs.h>
28 #include <linux/seq_file.h>
29 #include <linux/string.h>
30 #include <linux/smp.h>
31 #include <linux/types.h>
32 #include <linux/uaccess.h>
33 
34 #include <linux/i8k.h>
35 
36 #define I8K_SMM_FN_STATUS	0x0025
37 #define I8K_SMM_POWER_STATUS	0x0069
38 #define I8K_SMM_SET_FAN		0x01a3
39 #define I8K_SMM_GET_FAN		0x00a3
40 #define I8K_SMM_GET_SPEED	0x02a3
41 #define I8K_SMM_GET_FAN_TYPE	0x03a3
42 #define I8K_SMM_GET_NOM_SPEED	0x04a3
43 #define I8K_SMM_GET_TEMP	0x10a3
44 #define I8K_SMM_GET_TEMP_TYPE	0x11a3
45 #define I8K_SMM_GET_DELL_SIG1	0xfea3
46 #define I8K_SMM_GET_DELL_SIG2	0xffa3
47 
48 #define I8K_FAN_MULT		30
49 #define I8K_FAN_MAX_RPM		30000
50 #define I8K_MAX_TEMP		127
51 
52 #define I8K_FN_NONE		0x00
53 #define I8K_FN_UP		0x01
54 #define I8K_FN_DOWN		0x02
55 #define I8K_FN_MUTE		0x04
56 #define I8K_FN_MASK		0x07
57 #define I8K_FN_SHIFT		8
58 
59 #define I8K_POWER_AC		0x05
60 #define I8K_POWER_BATTERY	0x01
61 
62 #define DELL_SMM_NO_TEMP	10
63 #define DELL_SMM_NO_FANS	3
64 
65 struct dell_smm_data {
66 	struct mutex i8k_mutex; /* lock for sensors writes */
67 	char bios_version[4];
68 	char bios_machineid[16];
69 	uint i8k_fan_mult;
70 	uint i8k_pwm_mult;
71 	uint i8k_fan_max;
72 	bool disallow_fan_type_call;
73 	bool disallow_fan_support;
74 	unsigned int manual_fan;
75 	unsigned int auto_fan;
76 	int temp_type[DELL_SMM_NO_TEMP];
77 	bool fan[DELL_SMM_NO_FANS];
78 	int fan_type[DELL_SMM_NO_FANS];
79 	int *fan_nominal_speed[DELL_SMM_NO_FANS];
80 };
81 
82 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
83 MODULE_AUTHOR("Pali Rohár <pali@kernel.org>");
84 MODULE_DESCRIPTION("Dell laptop SMM BIOS hwmon driver");
85 MODULE_LICENSE("GPL");
86 MODULE_ALIAS("i8k");
87 
88 static bool force;
89 module_param(force, bool, 0);
90 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
91 
92 static bool ignore_dmi;
93 module_param(ignore_dmi, bool, 0);
94 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
95 
96 #if IS_ENABLED(CONFIG_I8K)
97 static bool restricted = true;
98 module_param(restricted, bool, 0);
99 MODULE_PARM_DESC(restricted, "Restrict fan control and serial number to CAP_SYS_ADMIN (default: 1)");
100 
101 static bool power_status;
102 module_param(power_status, bool, 0600);
103 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k (default: 0)");
104 #endif
105 
106 static uint fan_mult;
107 module_param(fan_mult, uint, 0);
108 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with (default: autodetect)");
109 
110 static uint fan_max;
111 module_param(fan_max, uint, 0);
112 MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autodetect)");
113 
114 struct smm_regs {
115 	unsigned int eax;
116 	unsigned int ebx;
117 	unsigned int ecx;
118 	unsigned int edx;
119 	unsigned int esi;
120 	unsigned int edi;
121 } __packed;
122 
123 static const char * const temp_labels[] = {
124 	"CPU",
125 	"GPU",
126 	"SODIMM",
127 	"Other",
128 	"Ambient",
129 	"Other",
130 };
131 
132 static const char * const fan_labels[] = {
133 	"Processor Fan",
134 	"Motherboard Fan",
135 	"Video Fan",
136 	"Power Supply Fan",
137 	"Chipset Fan",
138 	"Other Fan",
139 };
140 
141 static const char * const docking_labels[] = {
142 	"Docking Processor Fan",
143 	"Docking Motherboard Fan",
144 	"Docking Video Fan",
145 	"Docking Power Supply Fan",
146 	"Docking Chipset Fan",
147 	"Docking Other Fan",
148 };
149 
150 static inline const char __init *i8k_get_dmi_data(int field)
151 {
152 	const char *dmi_data = dmi_get_system_info(field);
153 
154 	return dmi_data && *dmi_data ? dmi_data : "?";
155 }
156 
157 /*
158  * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
159  */
160 static int i8k_smm_func(void *par)
161 {
162 	ktime_t calltime = ktime_get();
163 	struct smm_regs *regs = par;
164 	int eax = regs->eax;
165 	int ebx = regs->ebx;
166 	long long duration;
167 	int rc;
168 
169 	/* SMM requires CPU 0 */
170 	if (smp_processor_id() != 0)
171 		return -EBUSY;
172 
173 #if defined(CONFIG_X86_64)
174 	asm volatile("pushq %%rax\n\t"
175 		"movl 0(%%rax),%%edx\n\t"
176 		"pushq %%rdx\n\t"
177 		"movl 4(%%rax),%%ebx\n\t"
178 		"movl 8(%%rax),%%ecx\n\t"
179 		"movl 12(%%rax),%%edx\n\t"
180 		"movl 16(%%rax),%%esi\n\t"
181 		"movl 20(%%rax),%%edi\n\t"
182 		"popq %%rax\n\t"
183 		"out %%al,$0xb2\n\t"
184 		"out %%al,$0x84\n\t"
185 		"xchgq %%rax,(%%rsp)\n\t"
186 		"movl %%ebx,4(%%rax)\n\t"
187 		"movl %%ecx,8(%%rax)\n\t"
188 		"movl %%edx,12(%%rax)\n\t"
189 		"movl %%esi,16(%%rax)\n\t"
190 		"movl %%edi,20(%%rax)\n\t"
191 		"popq %%rdx\n\t"
192 		"movl %%edx,0(%%rax)\n\t"
193 		"pushfq\n\t"
194 		"popq %%rax\n\t"
195 		"andl $1,%%eax\n"
196 		: "=a"(rc)
197 		:    "a"(regs)
198 		:    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
199 #else
200 	asm volatile("pushl %%eax\n\t"
201 	    "movl 0(%%eax),%%edx\n\t"
202 	    "push %%edx\n\t"
203 	    "movl 4(%%eax),%%ebx\n\t"
204 	    "movl 8(%%eax),%%ecx\n\t"
205 	    "movl 12(%%eax),%%edx\n\t"
206 	    "movl 16(%%eax),%%esi\n\t"
207 	    "movl 20(%%eax),%%edi\n\t"
208 	    "popl %%eax\n\t"
209 	    "out %%al,$0xb2\n\t"
210 	    "out %%al,$0x84\n\t"
211 	    "xchgl %%eax,(%%esp)\n\t"
212 	    "movl %%ebx,4(%%eax)\n\t"
213 	    "movl %%ecx,8(%%eax)\n\t"
214 	    "movl %%edx,12(%%eax)\n\t"
215 	    "movl %%esi,16(%%eax)\n\t"
216 	    "movl %%edi,20(%%eax)\n\t"
217 	    "popl %%edx\n\t"
218 	    "movl %%edx,0(%%eax)\n\t"
219 	    "lahf\n\t"
220 	    "shrl $8,%%eax\n\t"
221 	    "andl $1,%%eax\n"
222 	    : "=a"(rc)
223 	    :    "a"(regs)
224 	    :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
225 #endif
226 	if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
227 		rc = -EINVAL;
228 
229 	duration = ktime_us_delta(ktime_get(), calltime);
230 	pr_debug("smm(0x%.4x 0x%.4x) = 0x%.4x  (took %7lld usecs)\n", eax, ebx,
231 		 (rc ? 0xffff : regs->eax & 0xffff), duration);
232 
233 	return rc;
234 }
235 
236 /*
237  * Call the System Management Mode BIOS.
238  */
239 static int i8k_smm(struct smm_regs *regs)
240 {
241 	int ret;
242 
243 	cpus_read_lock();
244 	ret = smp_call_on_cpu(0, i8k_smm_func, regs, true);
245 	cpus_read_unlock();
246 
247 	return ret;
248 }
249 
250 /*
251  * Read the fan status.
252  */
253 static int i8k_get_fan_status(const struct dell_smm_data *data, int fan)
254 {
255 	struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
256 
257 	if (data->disallow_fan_support)
258 		return -EINVAL;
259 
260 	regs.ebx = fan & 0xff;
261 	return i8k_smm(&regs) ? : regs.eax & 0xff;
262 }
263 
264 /*
265  * Read the fan speed in RPM.
266  */
267 static int i8k_get_fan_speed(const struct dell_smm_data *data, int fan)
268 {
269 	struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
270 
271 	if (data->disallow_fan_support)
272 		return -EINVAL;
273 
274 	regs.ebx = fan & 0xff;
275 	return i8k_smm(&regs) ? : (regs.eax & 0xffff) * data->i8k_fan_mult;
276 }
277 
278 /*
279  * Read the fan type.
280  */
281 static int _i8k_get_fan_type(const struct dell_smm_data *data, int fan)
282 {
283 	struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_TYPE, };
284 
285 	if (data->disallow_fan_support || data->disallow_fan_type_call)
286 		return -EINVAL;
287 
288 	regs.ebx = fan & 0xff;
289 	return i8k_smm(&regs) ? : regs.eax & 0xff;
290 }
291 
292 static int i8k_get_fan_type(struct dell_smm_data *data, int fan)
293 {
294 	/* I8K_SMM_GET_FAN_TYPE SMM call is expensive, so cache values */
295 	if (data->fan_type[fan] == INT_MIN)
296 		data->fan_type[fan] = _i8k_get_fan_type(data, fan);
297 
298 	return data->fan_type[fan];
299 }
300 
301 /*
302  * Read the fan nominal rpm for specific fan speed.
303  */
304 static int __init i8k_get_fan_nominal_speed(const struct dell_smm_data *data, int fan, int speed)
305 {
306 	struct smm_regs regs = { .eax = I8K_SMM_GET_NOM_SPEED, };
307 
308 	if (data->disallow_fan_support)
309 		return -EINVAL;
310 
311 	regs.ebx = (fan & 0xff) | (speed << 8);
312 	return i8k_smm(&regs) ? : (regs.eax & 0xffff) * data->i8k_fan_mult;
313 }
314 
315 /*
316  * Enable or disable automatic BIOS fan control support
317  */
318 static int i8k_enable_fan_auto_mode(const struct dell_smm_data *data, bool enable)
319 {
320 	struct smm_regs regs = { };
321 
322 	if (data->disallow_fan_support)
323 		return -EINVAL;
324 
325 	regs.eax = enable ? data->auto_fan : data->manual_fan;
326 	return i8k_smm(&regs);
327 }
328 
329 /*
330  * Set the fan speed (off, low, high, ...).
331  */
332 static int i8k_set_fan(const struct dell_smm_data *data, int fan, int speed)
333 {
334 	struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
335 
336 	if (data->disallow_fan_support)
337 		return -EINVAL;
338 
339 	speed = (speed < 0) ? 0 : ((speed > data->i8k_fan_max) ? data->i8k_fan_max : speed);
340 	regs.ebx = (fan & 0xff) | (speed << 8);
341 
342 	return i8k_smm(&regs);
343 }
344 
345 static int __init i8k_get_temp_type(int sensor)
346 {
347 	struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP_TYPE, };
348 
349 	regs.ebx = sensor & 0xff;
350 	return i8k_smm(&regs) ? : regs.eax & 0xff;
351 }
352 
353 /*
354  * Read the cpu temperature.
355  */
356 static int _i8k_get_temp(int sensor)
357 {
358 	struct smm_regs regs = {
359 		.eax = I8K_SMM_GET_TEMP,
360 		.ebx = sensor & 0xff,
361 	};
362 
363 	return i8k_smm(&regs) ? : regs.eax & 0xff;
364 }
365 
366 static int i8k_get_temp(int sensor)
367 {
368 	int temp = _i8k_get_temp(sensor);
369 
370 	/*
371 	 * Sometimes the temperature sensor returns 0x99, which is out of range.
372 	 * In this case we retry (once) before returning an error.
373 	 # 1003655137 00000058 00005a4b
374 	 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
375 	 # 1003655139 00000054 00005c52
376 	 */
377 	if (temp == 0x99) {
378 		msleep(100);
379 		temp = _i8k_get_temp(sensor);
380 	}
381 	/*
382 	 * Return -ENODATA for all invalid temperatures.
383 	 *
384 	 * Known instances are the 0x99 value as seen above as well as
385 	 * 0xc1 (193), which may be returned when trying to read the GPU
386 	 * temperature if the system supports a GPU and it is currently
387 	 * turned off.
388 	 */
389 	if (temp > I8K_MAX_TEMP)
390 		return -ENODATA;
391 
392 	return temp;
393 }
394 
395 static int __init i8k_get_dell_signature(int req_fn)
396 {
397 	struct smm_regs regs = { .eax = req_fn, };
398 	int rc;
399 
400 	rc = i8k_smm(&regs);
401 	if (rc < 0)
402 		return rc;
403 
404 	return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
405 }
406 
407 #if IS_ENABLED(CONFIG_I8K)
408 
409 /*
410  * Read the Fn key status.
411  */
412 static int i8k_get_fn_status(void)
413 {
414 	struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
415 	int rc;
416 
417 	rc = i8k_smm(&regs);
418 	if (rc < 0)
419 		return rc;
420 
421 	switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
422 	case I8K_FN_UP:
423 		return I8K_VOL_UP;
424 	case I8K_FN_DOWN:
425 		return I8K_VOL_DOWN;
426 	case I8K_FN_MUTE:
427 		return I8K_VOL_MUTE;
428 	default:
429 		return 0;
430 	}
431 }
432 
433 /*
434  * Read the power status.
435  */
436 static int i8k_get_power_status(void)
437 {
438 	struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
439 	int rc;
440 
441 	rc = i8k_smm(&regs);
442 	if (rc < 0)
443 		return rc;
444 
445 	return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
446 }
447 
448 /*
449  * Procfs interface
450  */
451 
452 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
453 {
454 	struct dell_smm_data *data = pde_data(file_inode(fp));
455 	int __user *argp = (int __user *)arg;
456 	int speed, err;
457 	int val = 0;
458 
459 	if (!argp)
460 		return -EINVAL;
461 
462 	switch (cmd) {
463 	case I8K_BIOS_VERSION:
464 		if (!isdigit(data->bios_version[0]) || !isdigit(data->bios_version[1]) ||
465 		    !isdigit(data->bios_version[2]))
466 			return -EINVAL;
467 
468 		val = (data->bios_version[0] << 16) |
469 				(data->bios_version[1] << 8) | data->bios_version[2];
470 
471 		if (copy_to_user(argp, &val, sizeof(val)))
472 			return -EFAULT;
473 
474 		return 0;
475 	case I8K_MACHINE_ID:
476 		if (restricted && !capable(CAP_SYS_ADMIN))
477 			return -EPERM;
478 
479 		if (copy_to_user(argp, data->bios_machineid, sizeof(data->bios_machineid)))
480 			return -EFAULT;
481 
482 		return 0;
483 	case I8K_FN_STATUS:
484 		val = i8k_get_fn_status();
485 		break;
486 
487 	case I8K_POWER_STATUS:
488 		val = i8k_get_power_status();
489 		break;
490 
491 	case I8K_GET_TEMP:
492 		val = i8k_get_temp(0);
493 		break;
494 
495 	case I8K_GET_SPEED:
496 		if (copy_from_user(&val, argp, sizeof(int)))
497 			return -EFAULT;
498 
499 		val = i8k_get_fan_speed(data, val);
500 		break;
501 
502 	case I8K_GET_FAN:
503 		if (copy_from_user(&val, argp, sizeof(int)))
504 			return -EFAULT;
505 
506 		val = i8k_get_fan_status(data, val);
507 		break;
508 
509 	case I8K_SET_FAN:
510 		if (restricted && !capable(CAP_SYS_ADMIN))
511 			return -EPERM;
512 
513 		if (copy_from_user(&val, argp, sizeof(int)))
514 			return -EFAULT;
515 
516 		if (copy_from_user(&speed, argp + 1, sizeof(int)))
517 			return -EFAULT;
518 
519 		mutex_lock(&data->i8k_mutex);
520 		err = i8k_set_fan(data, val, speed);
521 		if (err < 0)
522 			val = err;
523 		else
524 			val = i8k_get_fan_status(data, val);
525 		mutex_unlock(&data->i8k_mutex);
526 		break;
527 
528 	default:
529 		return -ENOIOCTLCMD;
530 	}
531 
532 	if (val < 0)
533 		return val;
534 
535 	if (copy_to_user(argp, &val, sizeof(int)))
536 		return -EFAULT;
537 
538 	return 0;
539 }
540 
541 /*
542  * Print the information for /proc/i8k.
543  */
544 static int i8k_proc_show(struct seq_file *seq, void *offset)
545 {
546 	struct dell_smm_data *data = seq->private;
547 	int fn_key, cpu_temp, ac_power;
548 	int left_fan, right_fan, left_speed, right_speed;
549 
550 	cpu_temp	= i8k_get_temp(0);				/* 11100 µs */
551 	left_fan	= i8k_get_fan_status(data, I8K_FAN_LEFT);	/*   580 µs */
552 	right_fan	= i8k_get_fan_status(data, I8K_FAN_RIGHT);	/*   580 µs */
553 	left_speed	= i8k_get_fan_speed(data, I8K_FAN_LEFT);	/*   580 µs */
554 	right_speed	= i8k_get_fan_speed(data, I8K_FAN_RIGHT);	/*   580 µs */
555 	fn_key		= i8k_get_fn_status();				/*   750 µs */
556 	if (power_status)
557 		ac_power = i8k_get_power_status();			/* 14700 µs */
558 	else
559 		ac_power = -1;
560 
561 	/*
562 	 * Info:
563 	 *
564 	 * 1)  Format version (this will change if format changes)
565 	 * 2)  BIOS version
566 	 * 3)  BIOS machine ID
567 	 * 4)  Cpu temperature
568 	 * 5)  Left fan status
569 	 * 6)  Right fan status
570 	 * 7)  Left fan speed
571 	 * 8)  Right fan speed
572 	 * 9)  AC power
573 	 * 10) Fn Key status
574 	 */
575 	seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
576 		   I8K_PROC_FMT,
577 		   data->bios_version,
578 		   (restricted && !capable(CAP_SYS_ADMIN)) ? "-1" : data->bios_machineid,
579 		   cpu_temp,
580 		   left_fan, right_fan, left_speed, right_speed,
581 		   ac_power, fn_key);
582 
583 	return 0;
584 }
585 
586 static int i8k_open_fs(struct inode *inode, struct file *file)
587 {
588 	return single_open(file, i8k_proc_show, pde_data(inode));
589 }
590 
591 static const struct proc_ops i8k_proc_ops = {
592 	.proc_open	= i8k_open_fs,
593 	.proc_read	= seq_read,
594 	.proc_lseek	= seq_lseek,
595 	.proc_release	= single_release,
596 	.proc_ioctl	= i8k_ioctl,
597 };
598 
599 static void i8k_exit_procfs(void *param)
600 {
601 	remove_proc_entry("i8k", NULL);
602 }
603 
604 static void __init i8k_init_procfs(struct device *dev)
605 {
606 	struct dell_smm_data *data = dev_get_drvdata(dev);
607 
608 	/* Only register exit function if creation was successful */
609 	if (proc_create_data("i8k", 0, NULL, &i8k_proc_ops, data))
610 		devm_add_action_or_reset(dev, i8k_exit_procfs, NULL);
611 }
612 
613 #else
614 
615 static void __init i8k_init_procfs(struct device *dev)
616 {
617 }
618 
619 #endif
620 
621 /*
622  * Hwmon interface
623  */
624 
625 static umode_t dell_smm_is_visible(const void *drvdata, enum hwmon_sensor_types type, u32 attr,
626 				   int channel)
627 {
628 	const struct dell_smm_data *data = drvdata;
629 
630 	switch (type) {
631 	case hwmon_temp:
632 		switch (attr) {
633 		case hwmon_temp_input:
634 		case hwmon_temp_label:
635 			if (data->temp_type[channel] >= 0)
636 				return 0444;
637 
638 			break;
639 		default:
640 			break;
641 		}
642 		break;
643 	case hwmon_fan:
644 		if (data->disallow_fan_support)
645 			break;
646 
647 		switch (attr) {
648 		case hwmon_fan_input:
649 			if (data->fan[channel])
650 				return 0444;
651 
652 			break;
653 		case hwmon_fan_label:
654 			if (data->fan[channel] && !data->disallow_fan_type_call)
655 				return 0444;
656 
657 			break;
658 		case hwmon_fan_min:
659 		case hwmon_fan_max:
660 		case hwmon_fan_target:
661 			if (data->fan_nominal_speed[channel])
662 				return 0444;
663 
664 			break;
665 		default:
666 			break;
667 		}
668 		break;
669 	case hwmon_pwm:
670 		if (data->disallow_fan_support)
671 			break;
672 
673 		switch (attr) {
674 		case hwmon_pwm_input:
675 			if (data->fan[channel])
676 				return 0644;
677 
678 			break;
679 		case hwmon_pwm_enable:
680 			if (data->auto_fan)
681 				/*
682 				 * There is no command for retrieve the current status
683 				 * from BIOS, and userspace/firmware itself can change
684 				 * it.
685 				 * Thus we can only provide write-only access for now.
686 				 */
687 				return 0200;
688 
689 			break;
690 		default:
691 			break;
692 		}
693 		break;
694 	default:
695 		break;
696 	}
697 
698 	return 0;
699 }
700 
701 static int dell_smm_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
702 			 long *val)
703 {
704 	struct dell_smm_data *data = dev_get_drvdata(dev);
705 	int ret;
706 
707 	switch (type) {
708 	case hwmon_temp:
709 		switch (attr) {
710 		case hwmon_temp_input:
711 			ret = i8k_get_temp(channel);
712 			if (ret < 0)
713 				return ret;
714 
715 			*val = ret * 1000;
716 
717 			return 0;
718 		default:
719 			break;
720 		}
721 		break;
722 	case hwmon_fan:
723 		switch (attr) {
724 		case hwmon_fan_input:
725 			ret = i8k_get_fan_speed(data, channel);
726 			if (ret < 0)
727 				return ret;
728 
729 			*val = ret;
730 
731 			return 0;
732 		case hwmon_fan_min:
733 			*val = data->fan_nominal_speed[channel][0];
734 
735 			return 0;
736 		case hwmon_fan_max:
737 			*val = data->fan_nominal_speed[channel][data->i8k_fan_max];
738 
739 			return 0;
740 		case hwmon_fan_target:
741 			ret = i8k_get_fan_status(data, channel);
742 			if (ret < 0)
743 				return ret;
744 
745 			if (ret > data->i8k_fan_max)
746 				ret = data->i8k_fan_max;
747 
748 			*val = data->fan_nominal_speed[channel][ret];
749 
750 			return 0;
751 		default:
752 			break;
753 		}
754 		break;
755 	case hwmon_pwm:
756 		switch (attr) {
757 		case hwmon_pwm_input:
758 			ret = i8k_get_fan_status(data, channel);
759 			if (ret < 0)
760 				return ret;
761 
762 			*val = clamp_val(ret * data->i8k_pwm_mult, 0, 255);
763 
764 			return 0;
765 		default:
766 			break;
767 		}
768 		break;
769 	default:
770 		break;
771 	}
772 
773 	return -EOPNOTSUPP;
774 }
775 
776 static const char *dell_smm_fan_label(struct dell_smm_data *data, int channel)
777 {
778 	bool dock = false;
779 	int type = i8k_get_fan_type(data, channel);
780 
781 	if (type < 0)
782 		return ERR_PTR(type);
783 
784 	if (type & 0x10) {
785 		dock = true;
786 		type &= 0x0F;
787 	}
788 
789 	if (type >= ARRAY_SIZE(fan_labels))
790 		type = ARRAY_SIZE(fan_labels) - 1;
791 
792 	return dock ? docking_labels[type] : fan_labels[type];
793 }
794 
795 static int dell_smm_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
796 				int channel, const char **str)
797 {
798 	struct dell_smm_data *data = dev_get_drvdata(dev);
799 
800 	switch (type) {
801 	case hwmon_temp:
802 		switch (attr) {
803 		case hwmon_temp_label:
804 			*str = temp_labels[data->temp_type[channel]];
805 			return 0;
806 		default:
807 			break;
808 		}
809 		break;
810 	case hwmon_fan:
811 		switch (attr) {
812 		case hwmon_fan_label:
813 			*str = dell_smm_fan_label(data, channel);
814 			return PTR_ERR_OR_ZERO(*str);
815 		default:
816 			break;
817 		}
818 		break;
819 	default:
820 		break;
821 	}
822 
823 	return -EOPNOTSUPP;
824 }
825 
826 static int dell_smm_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
827 			  long val)
828 {
829 	struct dell_smm_data *data = dev_get_drvdata(dev);
830 	unsigned long pwm;
831 	bool enable;
832 	int err;
833 
834 	switch (type) {
835 	case hwmon_pwm:
836 		switch (attr) {
837 		case hwmon_pwm_input:
838 			pwm = clamp_val(DIV_ROUND_CLOSEST(val, data->i8k_pwm_mult), 0,
839 					data->i8k_fan_max);
840 
841 			mutex_lock(&data->i8k_mutex);
842 			err = i8k_set_fan(data, channel, pwm);
843 			mutex_unlock(&data->i8k_mutex);
844 
845 			if (err < 0)
846 				return err;
847 
848 			return 0;
849 		case hwmon_pwm_enable:
850 			if (!val)
851 				return -EINVAL;
852 
853 			if (val == 1)
854 				enable = false;
855 			else
856 				enable = true;
857 
858 			mutex_lock(&data->i8k_mutex);
859 			err = i8k_enable_fan_auto_mode(data, enable);
860 			mutex_unlock(&data->i8k_mutex);
861 
862 			if (err < 0)
863 				return err;
864 
865 			return 0;
866 		default:
867 			break;
868 		}
869 		break;
870 	default:
871 		break;
872 	}
873 
874 	return -EOPNOTSUPP;
875 }
876 
877 static const struct hwmon_ops dell_smm_ops = {
878 	.is_visible = dell_smm_is_visible,
879 	.read = dell_smm_read,
880 	.read_string = dell_smm_read_string,
881 	.write = dell_smm_write,
882 };
883 
884 static const struct hwmon_channel_info *dell_smm_info[] = {
885 	HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
886 	HWMON_CHANNEL_INFO(temp,
887 			   HWMON_T_INPUT | HWMON_T_LABEL,
888 			   HWMON_T_INPUT | HWMON_T_LABEL,
889 			   HWMON_T_INPUT | HWMON_T_LABEL,
890 			   HWMON_T_INPUT | HWMON_T_LABEL,
891 			   HWMON_T_INPUT | HWMON_T_LABEL,
892 			   HWMON_T_INPUT | HWMON_T_LABEL,
893 			   HWMON_T_INPUT | HWMON_T_LABEL,
894 			   HWMON_T_INPUT | HWMON_T_LABEL,
895 			   HWMON_T_INPUT | HWMON_T_LABEL,
896 			   HWMON_T_INPUT | HWMON_T_LABEL
897 			   ),
898 	HWMON_CHANNEL_INFO(fan,
899 			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
900 			   HWMON_F_TARGET,
901 			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
902 			   HWMON_F_TARGET,
903 			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
904 			   HWMON_F_TARGET
905 			   ),
906 	HWMON_CHANNEL_INFO(pwm,
907 			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
908 			   HWMON_PWM_INPUT,
909 			   HWMON_PWM_INPUT
910 			   ),
911 	NULL
912 };
913 
914 static const struct hwmon_chip_info dell_smm_chip_info = {
915 	.ops = &dell_smm_ops,
916 	.info = dell_smm_info,
917 };
918 
919 static int __init dell_smm_init_hwmon(struct device *dev)
920 {
921 	struct dell_smm_data *data = dev_get_drvdata(dev);
922 	struct device *dell_smm_hwmon_dev;
923 	int i, state, err;
924 
925 	for (i = 0; i < DELL_SMM_NO_TEMP; i++) {
926 		data->temp_type[i] = i8k_get_temp_type(i);
927 		if (data->temp_type[i] < 0)
928 			continue;
929 
930 		if (data->temp_type[i] >= ARRAY_SIZE(temp_labels))
931 			data->temp_type[i] = ARRAY_SIZE(temp_labels) - 1;
932 	}
933 
934 	for (i = 0; i < DELL_SMM_NO_FANS; i++) {
935 		data->fan_type[i] = INT_MIN;
936 		err = i8k_get_fan_status(data, i);
937 		if (err < 0)
938 			err = i8k_get_fan_type(data, i);
939 
940 		if (err < 0)
941 			continue;
942 
943 		data->fan[i] = true;
944 		data->fan_nominal_speed[i] = devm_kmalloc_array(dev, data->i8k_fan_max + 1,
945 								sizeof(*data->fan_nominal_speed[i]),
946 								GFP_KERNEL);
947 		if (!data->fan_nominal_speed[i])
948 			continue;
949 
950 		for (state = 0; state <= data->i8k_fan_max; state++) {
951 			err = i8k_get_fan_nominal_speed(data, i, state);
952 			if (err < 0) {
953 				/* Mark nominal speed table as invalid in case of error */
954 				devm_kfree(dev, data->fan_nominal_speed[i]);
955 				data->fan_nominal_speed[i] = NULL;
956 				break;
957 			}
958 			data->fan_nominal_speed[i][state] = err;
959 		}
960 	}
961 
962 	dell_smm_hwmon_dev = devm_hwmon_device_register_with_info(dev, "dell_smm", data,
963 								  &dell_smm_chip_info, NULL);
964 
965 	return PTR_ERR_OR_ZERO(dell_smm_hwmon_dev);
966 }
967 
968 struct i8k_config_data {
969 	uint fan_mult;
970 	uint fan_max;
971 };
972 
973 enum i8k_configs {
974 	DELL_LATITUDE_D520,
975 	DELL_PRECISION_490,
976 	DELL_STUDIO,
977 	DELL_XPS,
978 };
979 
980 /*
981  * Only use for machines which need some special configuration
982  * in order to work correctly (e.g. if autoconfig fails on this machines).
983  */
984 
985 static const struct i8k_config_data i8k_config_data[] __initconst = {
986 	[DELL_LATITUDE_D520] = {
987 		.fan_mult = 1,
988 		.fan_max = I8K_FAN_TURBO,
989 	},
990 	[DELL_PRECISION_490] = {
991 		.fan_mult = 1,
992 		.fan_max = I8K_FAN_TURBO,
993 	},
994 	[DELL_STUDIO] = {
995 		.fan_mult = 1,
996 		.fan_max = I8K_FAN_HIGH,
997 	},
998 	[DELL_XPS] = {
999 		.fan_mult = 1,
1000 		.fan_max = I8K_FAN_HIGH,
1001 	},
1002 };
1003 
1004 static const struct dmi_system_id i8k_dmi_table[] __initconst = {
1005 	{
1006 		.ident = "Dell Inspiron",
1007 		.matches = {
1008 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
1009 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
1010 		},
1011 	},
1012 	{
1013 		.ident = "Dell Latitude",
1014 		.matches = {
1015 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
1016 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
1017 		},
1018 	},
1019 	{
1020 		.ident = "Dell Inspiron 2",
1021 		.matches = {
1022 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1023 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
1024 		},
1025 	},
1026 	{
1027 		.ident = "Dell Latitude D520",
1028 		.matches = {
1029 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1030 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
1031 		},
1032 		.driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
1033 	},
1034 	{
1035 		.ident = "Dell Latitude 2",
1036 		.matches = {
1037 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1038 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
1039 		},
1040 	},
1041 	{	/* UK Inspiron 6400  */
1042 		.ident = "Dell Inspiron 3",
1043 		.matches = {
1044 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1045 			DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
1046 		},
1047 	},
1048 	{
1049 		.ident = "Dell Inspiron 3",
1050 		.matches = {
1051 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1052 			DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
1053 		},
1054 	},
1055 	{
1056 		.ident = "Dell Precision 490",
1057 		.matches = {
1058 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1059 			DMI_MATCH(DMI_PRODUCT_NAME,
1060 				  "Precision WorkStation 490"),
1061 		},
1062 		.driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
1063 	},
1064 	{
1065 		.ident = "Dell Precision",
1066 		.matches = {
1067 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1068 			DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
1069 		},
1070 	},
1071 	{
1072 		.ident = "Dell Vostro",
1073 		.matches = {
1074 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1075 			DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
1076 		},
1077 	},
1078 	{
1079 		.ident = "Dell Studio",
1080 		.matches = {
1081 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1082 			DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
1083 		},
1084 		.driver_data = (void *)&i8k_config_data[DELL_STUDIO],
1085 	},
1086 	{
1087 		.ident = "Dell XPS M140",
1088 		.matches = {
1089 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1090 			DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
1091 		},
1092 		.driver_data = (void *)&i8k_config_data[DELL_XPS],
1093 	},
1094 	{
1095 		.ident = "Dell XPS",
1096 		.matches = {
1097 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1098 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS"),
1099 		},
1100 	},
1101 	{ }
1102 };
1103 
1104 MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
1105 
1106 /*
1107  * On some machines once I8K_SMM_GET_FAN_TYPE is issued then CPU fan speed
1108  * randomly going up and down due to bug in Dell SMM or BIOS. Here is blacklist
1109  * of affected Dell machines for which we disallow I8K_SMM_GET_FAN_TYPE call.
1110  * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=100121
1111  */
1112 static const struct dmi_system_id i8k_blacklist_fan_type_dmi_table[] __initconst = {
1113 	{
1114 		.ident = "Dell Studio XPS 8000",
1115 		.matches = {
1116 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1117 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8000"),
1118 		},
1119 	},
1120 	{
1121 		.ident = "Dell Studio XPS 8100",
1122 		.matches = {
1123 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1124 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8100"),
1125 		},
1126 	},
1127 	{
1128 		.ident = "Dell Inspiron 580",
1129 		.matches = {
1130 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1131 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 580 "),
1132 		},
1133 	},
1134 	{ }
1135 };
1136 
1137 /*
1138  * On some machines all fan related SMM functions implemented by Dell BIOS
1139  * firmware freeze kernel for about 500ms. Until Dell fixes these problems fan
1140  * support for affected blacklisted Dell machines stay disabled.
1141  * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=195751
1142  */
1143 static const struct dmi_system_id i8k_blacklist_fan_support_dmi_table[] __initconst = {
1144 	{
1145 		.ident = "Dell Inspiron 7720",
1146 		.matches = {
1147 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1148 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 7720"),
1149 		},
1150 	},
1151 	{
1152 		.ident = "Dell Vostro 3360",
1153 		.matches = {
1154 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1155 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Vostro 3360"),
1156 		},
1157 	},
1158 	{
1159 		.ident = "Dell XPS13 9333",
1160 		.matches = {
1161 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1162 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS13 9333"),
1163 		},
1164 	},
1165 	{
1166 		.ident = "Dell XPS 15 L502X",
1167 		.matches = {
1168 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1169 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L502X"),
1170 		},
1171 	},
1172 	{ }
1173 };
1174 
1175 struct i8k_fan_control_data {
1176 	unsigned int manual_fan;
1177 	unsigned int auto_fan;
1178 };
1179 
1180 enum i8k_fan_controls {
1181 	I8K_FAN_34A3_35A3,
1182 };
1183 
1184 static const struct i8k_fan_control_data i8k_fan_control_data[] __initconst = {
1185 	[I8K_FAN_34A3_35A3] = {
1186 		.manual_fan = 0x34a3,
1187 		.auto_fan = 0x35a3,
1188 	},
1189 };
1190 
1191 static const struct dmi_system_id i8k_whitelist_fan_control[] __initconst = {
1192 	{
1193 		.ident = "Dell Latitude 5480",
1194 		.matches = {
1195 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1196 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude 5480"),
1197 		},
1198 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1199 	},
1200 	{
1201 		.ident = "Dell Latitude E6440",
1202 		.matches = {
1203 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1204 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E6440"),
1205 		},
1206 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1207 	},
1208 	{
1209 		.ident = "Dell Latitude E7440",
1210 		.matches = {
1211 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1212 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E7440"),
1213 		},
1214 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1215 	},
1216 	{
1217 		.ident = "Dell Precision 5530",
1218 		.matches = {
1219 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1220 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 5530"),
1221 		},
1222 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1223 	},
1224 	{
1225 		.ident = "Dell Precision 7510",
1226 		.matches = {
1227 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1228 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
1229 		},
1230 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1231 	},
1232 	{ }
1233 };
1234 
1235 static int __init dell_smm_probe(struct platform_device *pdev)
1236 {
1237 	struct dell_smm_data *data;
1238 	const struct dmi_system_id *id, *fan_control;
1239 	int fan, ret;
1240 
1241 	data = devm_kzalloc(&pdev->dev, sizeof(struct dell_smm_data), GFP_KERNEL);
1242 	if (!data)
1243 		return -ENOMEM;
1244 
1245 	mutex_init(&data->i8k_mutex);
1246 	data->i8k_fan_mult = I8K_FAN_MULT;
1247 	data->i8k_fan_max = I8K_FAN_HIGH;
1248 	platform_set_drvdata(pdev, data);
1249 
1250 	if (dmi_check_system(i8k_blacklist_fan_support_dmi_table)) {
1251 		dev_warn(&pdev->dev, "broken Dell BIOS detected, disallow fan support\n");
1252 		if (!force)
1253 			data->disallow_fan_support = true;
1254 	}
1255 
1256 	if (dmi_check_system(i8k_blacklist_fan_type_dmi_table)) {
1257 		dev_warn(&pdev->dev, "broken Dell BIOS detected, disallow fan type call\n");
1258 		if (!force)
1259 			data->disallow_fan_type_call = true;
1260 	}
1261 
1262 	strscpy(data->bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
1263 		sizeof(data->bios_version));
1264 	strscpy(data->bios_machineid, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
1265 		sizeof(data->bios_machineid));
1266 
1267 	/*
1268 	 * Set fan multiplier and maximal fan speed from dmi config
1269 	 * Values specified in module parameters override values from dmi
1270 	 */
1271 	id = dmi_first_match(i8k_dmi_table);
1272 	if (id && id->driver_data) {
1273 		const struct i8k_config_data *conf = id->driver_data;
1274 
1275 		if (!fan_mult && conf->fan_mult)
1276 			fan_mult = conf->fan_mult;
1277 
1278 		if (!fan_max && conf->fan_max)
1279 			fan_max = conf->fan_max;
1280 	}
1281 
1282 	data->i8k_fan_max = fan_max ? : I8K_FAN_HIGH;	/* Must not be 0 */
1283 	data->i8k_pwm_mult = DIV_ROUND_UP(255, data->i8k_fan_max);
1284 
1285 	fan_control = dmi_first_match(i8k_whitelist_fan_control);
1286 	if (fan_control && fan_control->driver_data) {
1287 		const struct i8k_fan_control_data *control = fan_control->driver_data;
1288 
1289 		data->manual_fan = control->manual_fan;
1290 		data->auto_fan = control->auto_fan;
1291 		dev_info(&pdev->dev, "enabling support for setting automatic/manual fan control\n");
1292 	}
1293 
1294 	if (!fan_mult) {
1295 		/*
1296 		 * Autodetect fan multiplier based on nominal rpm
1297 		 * If fan reports rpm value too high then set multiplier to 1
1298 		 */
1299 		for (fan = 0; fan < DELL_SMM_NO_FANS; ++fan) {
1300 			ret = i8k_get_fan_nominal_speed(data, fan, data->i8k_fan_max);
1301 			if (ret < 0)
1302 				continue;
1303 
1304 			if (ret > I8K_FAN_MAX_RPM)
1305 				data->i8k_fan_mult = 1;
1306 			break;
1307 		}
1308 	} else {
1309 		/* Fan multiplier was specified in module param or in dmi */
1310 		data->i8k_fan_mult = fan_mult;
1311 	}
1312 
1313 	ret = dell_smm_init_hwmon(&pdev->dev);
1314 	if (ret)
1315 		return ret;
1316 
1317 	i8k_init_procfs(&pdev->dev);
1318 
1319 	return 0;
1320 }
1321 
1322 static struct platform_driver dell_smm_driver = {
1323 	.driver		= {
1324 		.name	= KBUILD_MODNAME,
1325 	},
1326 };
1327 
1328 static struct platform_device *dell_smm_device;
1329 
1330 /*
1331  * Probe for the presence of a supported laptop.
1332  */
1333 static int __init i8k_init(void)
1334 {
1335 	/*
1336 	 * Get DMI information
1337 	 */
1338 	if (!dmi_check_system(i8k_dmi_table)) {
1339 		if (!ignore_dmi && !force)
1340 			return -ENODEV;
1341 
1342 		pr_info("not running on a supported Dell system.\n");
1343 		pr_info("vendor=%s, model=%s, version=%s\n",
1344 			i8k_get_dmi_data(DMI_SYS_VENDOR),
1345 			i8k_get_dmi_data(DMI_PRODUCT_NAME),
1346 			i8k_get_dmi_data(DMI_BIOS_VERSION));
1347 	}
1348 
1349 	/*
1350 	 * Get SMM Dell signature
1351 	 */
1352 	if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
1353 	    i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
1354 		pr_err("unable to get SMM Dell signature\n");
1355 		if (!force)
1356 			return -ENODEV;
1357 	}
1358 
1359 	dell_smm_device = platform_create_bundle(&dell_smm_driver, dell_smm_probe, NULL, 0, NULL,
1360 						 0);
1361 
1362 	return PTR_ERR_OR_ZERO(dell_smm_device);
1363 }
1364 
1365 static void __exit i8k_exit(void)
1366 {
1367 	platform_device_unregister(dell_smm_device);
1368 	platform_driver_unregister(&dell_smm_driver);
1369 }
1370 
1371 module_init(i8k_init);
1372 module_exit(i8k_exit);
1373