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 __packed;
117 	unsigned int ecx __packed;
118 	unsigned int edx __packed;
119 	unsigned int esi __packed;
120 	unsigned int edi __packed;
121 };
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 int
453 i8k_ioctl_unlocked(struct file *fp, struct dell_smm_data *data, unsigned int cmd, unsigned long arg)
454 {
455 	int val = 0;
456 	int speed, err;
457 	unsigned char buff[16];
458 	int __user *argp = (int __user *)arg;
459 
460 	if (!argp)
461 		return -EINVAL;
462 
463 	switch (cmd) {
464 	case I8K_BIOS_VERSION:
465 		if (!isdigit(data->bios_version[0]) || !isdigit(data->bios_version[1]) ||
466 		    !isdigit(data->bios_version[2]))
467 			return -EINVAL;
468 
469 		val = (data->bios_version[0] << 16) |
470 				(data->bios_version[1] << 8) | data->bios_version[2];
471 		break;
472 
473 	case I8K_MACHINE_ID:
474 		if (restricted && !capable(CAP_SYS_ADMIN))
475 			return -EPERM;
476 
477 		strscpy_pad(buff, data->bios_machineid, sizeof(buff));
478 		break;
479 
480 	case I8K_FN_STATUS:
481 		val = i8k_get_fn_status();
482 		break;
483 
484 	case I8K_POWER_STATUS:
485 		val = i8k_get_power_status();
486 		break;
487 
488 	case I8K_GET_TEMP:
489 		val = i8k_get_temp(0);
490 		break;
491 
492 	case I8K_GET_SPEED:
493 		if (copy_from_user(&val, argp, sizeof(int)))
494 			return -EFAULT;
495 
496 		val = i8k_get_fan_speed(data, val);
497 		break;
498 
499 	case I8K_GET_FAN:
500 		if (copy_from_user(&val, argp, sizeof(int)))
501 			return -EFAULT;
502 
503 		val = i8k_get_fan_status(data, val);
504 		break;
505 
506 	case I8K_SET_FAN:
507 		if (restricted && !capable(CAP_SYS_ADMIN))
508 			return -EPERM;
509 
510 		if (copy_from_user(&val, argp, sizeof(int)))
511 			return -EFAULT;
512 
513 		if (copy_from_user(&speed, argp + 1, sizeof(int)))
514 			return -EFAULT;
515 
516 		err = i8k_set_fan(data, val, speed);
517 		if (err < 0)
518 			return err;
519 
520 		val = i8k_get_fan_status(data, val);
521 		break;
522 
523 	default:
524 		return -ENOIOCTLCMD;
525 	}
526 
527 	if (val < 0)
528 		return val;
529 
530 	switch (cmd) {
531 	case I8K_BIOS_VERSION:
532 		if (copy_to_user(argp, &val, 4))
533 			return -EFAULT;
534 
535 		break;
536 	case I8K_MACHINE_ID:
537 		if (copy_to_user(argp, buff, 16))
538 			return -EFAULT;
539 
540 		break;
541 	default:
542 		if (copy_to_user(argp, &val, sizeof(int)))
543 			return -EFAULT;
544 
545 		break;
546 	}
547 
548 	return 0;
549 }
550 
551 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
552 {
553 	struct dell_smm_data *data = PDE_DATA(file_inode(fp));
554 	long ret;
555 
556 	mutex_lock(&data->i8k_mutex);
557 	ret = i8k_ioctl_unlocked(fp, data, cmd, arg);
558 	mutex_unlock(&data->i8k_mutex);
559 
560 	return ret;
561 }
562 
563 /*
564  * Print the information for /proc/i8k.
565  */
566 static int i8k_proc_show(struct seq_file *seq, void *offset)
567 {
568 	struct dell_smm_data *data = seq->private;
569 	int fn_key, cpu_temp, ac_power;
570 	int left_fan, right_fan, left_speed, right_speed;
571 
572 	cpu_temp	= i8k_get_temp(0);				/* 11100 µs */
573 	left_fan	= i8k_get_fan_status(data, I8K_FAN_LEFT);	/*   580 µs */
574 	right_fan	= i8k_get_fan_status(data, I8K_FAN_RIGHT);	/*   580 µs */
575 	left_speed	= i8k_get_fan_speed(data, I8K_FAN_LEFT);	/*   580 µs */
576 	right_speed	= i8k_get_fan_speed(data, I8K_FAN_RIGHT);	/*   580 µs */
577 	fn_key		= i8k_get_fn_status();				/*   750 µs */
578 	if (power_status)
579 		ac_power = i8k_get_power_status();			/* 14700 µs */
580 	else
581 		ac_power = -1;
582 
583 	/*
584 	 * Info:
585 	 *
586 	 * 1)  Format version (this will change if format changes)
587 	 * 2)  BIOS version
588 	 * 3)  BIOS machine ID
589 	 * 4)  Cpu temperature
590 	 * 5)  Left fan status
591 	 * 6)  Right fan status
592 	 * 7)  Left fan speed
593 	 * 8)  Right fan speed
594 	 * 9)  AC power
595 	 * 10) Fn Key status
596 	 */
597 	seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
598 		   I8K_PROC_FMT,
599 		   data->bios_version,
600 		   (restricted && !capable(CAP_SYS_ADMIN)) ? "-1" : data->bios_machineid,
601 		   cpu_temp,
602 		   left_fan, right_fan, left_speed, right_speed,
603 		   ac_power, fn_key);
604 
605 	return 0;
606 }
607 
608 static int i8k_open_fs(struct inode *inode, struct file *file)
609 {
610 	return single_open(file, i8k_proc_show, PDE_DATA(inode));
611 }
612 
613 static const struct proc_ops i8k_proc_ops = {
614 	.proc_open	= i8k_open_fs,
615 	.proc_read	= seq_read,
616 	.proc_lseek	= seq_lseek,
617 	.proc_release	= single_release,
618 	.proc_ioctl	= i8k_ioctl,
619 };
620 
621 static void i8k_exit_procfs(void *param)
622 {
623 	remove_proc_entry("i8k", NULL);
624 }
625 
626 static void __init i8k_init_procfs(struct device *dev)
627 {
628 	struct dell_smm_data *data = dev_get_drvdata(dev);
629 
630 	/* Register the proc entry */
631 	proc_create_data("i8k", 0, NULL, &i8k_proc_ops, data);
632 
633 	devm_add_action_or_reset(dev, i8k_exit_procfs, NULL);
634 }
635 
636 #else
637 
638 static void __init i8k_init_procfs(struct device *dev)
639 {
640 }
641 
642 #endif
643 
644 /*
645  * Hwmon interface
646  */
647 
648 static umode_t dell_smm_is_visible(const void *drvdata, enum hwmon_sensor_types type, u32 attr,
649 				   int channel)
650 {
651 	const struct dell_smm_data *data = drvdata;
652 
653 	switch (type) {
654 	case hwmon_temp:
655 		switch (attr) {
656 		case hwmon_temp_input:
657 		case hwmon_temp_label:
658 			if (data->temp_type[channel] >= 0)
659 				return 0444;
660 
661 			break;
662 		default:
663 			break;
664 		}
665 		break;
666 	case hwmon_fan:
667 		if (data->disallow_fan_support)
668 			break;
669 
670 		switch (attr) {
671 		case hwmon_fan_input:
672 			if (data->fan[channel])
673 				return 0444;
674 
675 			break;
676 		case hwmon_fan_label:
677 			if (data->fan[channel] && !data->disallow_fan_type_call)
678 				return 0444;
679 
680 			break;
681 		case hwmon_fan_min:
682 		case hwmon_fan_max:
683 		case hwmon_fan_target:
684 			if (data->fan_nominal_speed[channel])
685 				return 0444;
686 
687 			break;
688 		default:
689 			break;
690 		}
691 		break;
692 	case hwmon_pwm:
693 		if (data->disallow_fan_support)
694 			break;
695 
696 		switch (attr) {
697 		case hwmon_pwm_input:
698 			if (data->fan[channel])
699 				return 0644;
700 
701 			break;
702 		case hwmon_pwm_enable:
703 			if (data->auto_fan)
704 				/*
705 				 * There is no command for retrieve the current status
706 				 * from BIOS, and userspace/firmware itself can change
707 				 * it.
708 				 * Thus we can only provide write-only access for now.
709 				 */
710 				return 0200;
711 
712 			break;
713 		default:
714 			break;
715 		}
716 		break;
717 	default:
718 		break;
719 	}
720 
721 	return 0;
722 }
723 
724 static int dell_smm_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
725 			 long *val)
726 {
727 	struct dell_smm_data *data = dev_get_drvdata(dev);
728 	int ret;
729 
730 	switch (type) {
731 	case hwmon_temp:
732 		switch (attr) {
733 		case hwmon_temp_input:
734 			ret = i8k_get_temp(channel);
735 			if (ret < 0)
736 				return ret;
737 
738 			*val = ret * 1000;
739 
740 			return 0;
741 		default:
742 			break;
743 		}
744 		break;
745 	case hwmon_fan:
746 		switch (attr) {
747 		case hwmon_fan_input:
748 			ret = i8k_get_fan_speed(data, channel);
749 			if (ret < 0)
750 				return ret;
751 
752 			*val = ret;
753 
754 			return 0;
755 		case hwmon_fan_min:
756 			*val = data->fan_nominal_speed[channel][0];
757 
758 			return 0;
759 		case hwmon_fan_max:
760 			*val = data->fan_nominal_speed[channel][data->i8k_fan_max];
761 
762 			return 0;
763 		case hwmon_fan_target:
764 			ret = i8k_get_fan_status(data, channel);
765 			if (ret < 0)
766 				return ret;
767 
768 			if (ret > data->i8k_fan_max)
769 				ret = data->i8k_fan_max;
770 
771 			*val = data->fan_nominal_speed[channel][ret];
772 
773 			return 0;
774 		default:
775 			break;
776 		}
777 		break;
778 	case hwmon_pwm:
779 		switch (attr) {
780 		case hwmon_pwm_input:
781 			ret = i8k_get_fan_status(data, channel);
782 			if (ret < 0)
783 				return ret;
784 
785 			*val = clamp_val(ret * data->i8k_pwm_mult, 0, 255);
786 
787 			return 0;
788 		default:
789 			break;
790 		}
791 		break;
792 	default:
793 		break;
794 	}
795 
796 	return -EOPNOTSUPP;
797 }
798 
799 static const char *dell_smm_fan_label(struct dell_smm_data *data, int channel)
800 {
801 	bool dock = false;
802 	int type = i8k_get_fan_type(data, channel);
803 
804 	if (type < 0)
805 		return ERR_PTR(type);
806 
807 	if (type & 0x10) {
808 		dock = true;
809 		type &= 0x0F;
810 	}
811 
812 	if (type >= ARRAY_SIZE(fan_labels))
813 		type = ARRAY_SIZE(fan_labels) - 1;
814 
815 	return dock ? docking_labels[type] : fan_labels[type];
816 }
817 
818 static int dell_smm_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
819 				int channel, const char **str)
820 {
821 	struct dell_smm_data *data = dev_get_drvdata(dev);
822 
823 	switch (type) {
824 	case hwmon_temp:
825 		switch (attr) {
826 		case hwmon_temp_label:
827 			*str = temp_labels[data->temp_type[channel]];
828 			return 0;
829 		default:
830 			break;
831 		}
832 		break;
833 	case hwmon_fan:
834 		switch (attr) {
835 		case hwmon_fan_label:
836 			*str = dell_smm_fan_label(data, channel);
837 			return PTR_ERR_OR_ZERO(*str);
838 		default:
839 			break;
840 		}
841 		break;
842 	default:
843 		break;
844 	}
845 
846 	return -EOPNOTSUPP;
847 }
848 
849 static int dell_smm_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
850 			  long val)
851 {
852 	struct dell_smm_data *data = dev_get_drvdata(dev);
853 	unsigned long pwm;
854 	bool enable;
855 	int err;
856 
857 	switch (type) {
858 	case hwmon_pwm:
859 		switch (attr) {
860 		case hwmon_pwm_input:
861 			pwm = clamp_val(DIV_ROUND_CLOSEST(val, data->i8k_pwm_mult), 0,
862 					data->i8k_fan_max);
863 
864 			mutex_lock(&data->i8k_mutex);
865 			err = i8k_set_fan(data, channel, pwm);
866 			mutex_unlock(&data->i8k_mutex);
867 
868 			if (err < 0)
869 				return err;
870 
871 			return 0;
872 		case hwmon_pwm_enable:
873 			if (!val)
874 				return -EINVAL;
875 
876 			if (val == 1)
877 				enable = false;
878 			else
879 				enable = true;
880 
881 			mutex_lock(&data->i8k_mutex);
882 			err = i8k_enable_fan_auto_mode(data, enable);
883 			mutex_unlock(&data->i8k_mutex);
884 
885 			if (err < 0)
886 				return err;
887 
888 			return 0;
889 		default:
890 			break;
891 		}
892 		break;
893 	default:
894 		break;
895 	}
896 
897 	return -EOPNOTSUPP;
898 }
899 
900 static const struct hwmon_ops dell_smm_ops = {
901 	.is_visible = dell_smm_is_visible,
902 	.read = dell_smm_read,
903 	.read_string = dell_smm_read_string,
904 	.write = dell_smm_write,
905 };
906 
907 static const struct hwmon_channel_info *dell_smm_info[] = {
908 	HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
909 	HWMON_CHANNEL_INFO(temp,
910 			   HWMON_T_INPUT | HWMON_T_LABEL,
911 			   HWMON_T_INPUT | HWMON_T_LABEL,
912 			   HWMON_T_INPUT | HWMON_T_LABEL,
913 			   HWMON_T_INPUT | HWMON_T_LABEL,
914 			   HWMON_T_INPUT | HWMON_T_LABEL,
915 			   HWMON_T_INPUT | HWMON_T_LABEL,
916 			   HWMON_T_INPUT | HWMON_T_LABEL,
917 			   HWMON_T_INPUT | HWMON_T_LABEL,
918 			   HWMON_T_INPUT | HWMON_T_LABEL,
919 			   HWMON_T_INPUT | HWMON_T_LABEL
920 			   ),
921 	HWMON_CHANNEL_INFO(fan,
922 			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
923 			   HWMON_F_TARGET,
924 			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
925 			   HWMON_F_TARGET,
926 			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
927 			   HWMON_F_TARGET
928 			   ),
929 	HWMON_CHANNEL_INFO(pwm,
930 			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
931 			   HWMON_PWM_INPUT,
932 			   HWMON_PWM_INPUT
933 			   ),
934 	NULL
935 };
936 
937 static const struct hwmon_chip_info dell_smm_chip_info = {
938 	.ops = &dell_smm_ops,
939 	.info = dell_smm_info,
940 };
941 
942 static int __init dell_smm_init_hwmon(struct device *dev)
943 {
944 	struct dell_smm_data *data = dev_get_drvdata(dev);
945 	struct device *dell_smm_hwmon_dev;
946 	int i, state, err;
947 
948 	for (i = 0; i < DELL_SMM_NO_TEMP; i++) {
949 		data->temp_type[i] = i8k_get_temp_type(i);
950 		if (data->temp_type[i] < 0)
951 			continue;
952 
953 		if (data->temp_type[i] >= ARRAY_SIZE(temp_labels))
954 			data->temp_type[i] = ARRAY_SIZE(temp_labels) - 1;
955 	}
956 
957 	for (i = 0; i < DELL_SMM_NO_FANS; i++) {
958 		data->fan_type[i] = INT_MIN;
959 		err = i8k_get_fan_status(data, i);
960 		if (err < 0)
961 			err = i8k_get_fan_type(data, i);
962 
963 		if (err < 0)
964 			continue;
965 
966 		data->fan[i] = true;
967 		data->fan_nominal_speed[i] = devm_kmalloc_array(dev, data->i8k_fan_max + 1,
968 								sizeof(*data->fan_nominal_speed[i]),
969 								GFP_KERNEL);
970 		if (!data->fan_nominal_speed[i])
971 			continue;
972 
973 		for (state = 0; state <= data->i8k_fan_max; state++) {
974 			err = i8k_get_fan_nominal_speed(data, i, state);
975 			if (err < 0) {
976 				/* Mark nominal speed table as invalid in case of error */
977 				devm_kfree(dev, data->fan_nominal_speed[i]);
978 				data->fan_nominal_speed[i] = NULL;
979 				break;
980 			}
981 			data->fan_nominal_speed[i][state] = err;
982 		}
983 	}
984 
985 	dell_smm_hwmon_dev = devm_hwmon_device_register_with_info(dev, "dell_smm", data,
986 								  &dell_smm_chip_info, NULL);
987 
988 	return PTR_ERR_OR_ZERO(dell_smm_hwmon_dev);
989 }
990 
991 struct i8k_config_data {
992 	uint fan_mult;
993 	uint fan_max;
994 };
995 
996 enum i8k_configs {
997 	DELL_LATITUDE_D520,
998 	DELL_PRECISION_490,
999 	DELL_STUDIO,
1000 	DELL_XPS,
1001 };
1002 
1003 /*
1004  * Only use for machines which need some special configuration
1005  * in order to work correctly (e.g. if autoconfig fails on this machines).
1006  */
1007 
1008 static const struct i8k_config_data i8k_config_data[] __initconst = {
1009 	[DELL_LATITUDE_D520] = {
1010 		.fan_mult = 1,
1011 		.fan_max = I8K_FAN_TURBO,
1012 	},
1013 	[DELL_PRECISION_490] = {
1014 		.fan_mult = 1,
1015 		.fan_max = I8K_FAN_TURBO,
1016 	},
1017 	[DELL_STUDIO] = {
1018 		.fan_mult = 1,
1019 		.fan_max = I8K_FAN_HIGH,
1020 	},
1021 	[DELL_XPS] = {
1022 		.fan_mult = 1,
1023 		.fan_max = I8K_FAN_HIGH,
1024 	},
1025 };
1026 
1027 static const struct dmi_system_id i8k_dmi_table[] __initconst = {
1028 	{
1029 		.ident = "Dell Inspiron",
1030 		.matches = {
1031 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
1032 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
1033 		},
1034 	},
1035 	{
1036 		.ident = "Dell Latitude",
1037 		.matches = {
1038 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
1039 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
1040 		},
1041 	},
1042 	{
1043 		.ident = "Dell Inspiron 2",
1044 		.matches = {
1045 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1046 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
1047 		},
1048 	},
1049 	{
1050 		.ident = "Dell Latitude D520",
1051 		.matches = {
1052 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1053 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
1054 		},
1055 		.driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
1056 	},
1057 	{
1058 		.ident = "Dell Latitude 2",
1059 		.matches = {
1060 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1061 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
1062 		},
1063 	},
1064 	{	/* UK Inspiron 6400  */
1065 		.ident = "Dell Inspiron 3",
1066 		.matches = {
1067 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1068 			DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
1069 		},
1070 	},
1071 	{
1072 		.ident = "Dell Inspiron 3",
1073 		.matches = {
1074 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1075 			DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
1076 		},
1077 	},
1078 	{
1079 		.ident = "Dell Precision 490",
1080 		.matches = {
1081 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1082 			DMI_MATCH(DMI_PRODUCT_NAME,
1083 				  "Precision WorkStation 490"),
1084 		},
1085 		.driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
1086 	},
1087 	{
1088 		.ident = "Dell Precision",
1089 		.matches = {
1090 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1091 			DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
1092 		},
1093 	},
1094 	{
1095 		.ident = "Dell Vostro",
1096 		.matches = {
1097 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1098 			DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
1099 		},
1100 	},
1101 	{
1102 		.ident = "Dell Studio",
1103 		.matches = {
1104 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1105 			DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
1106 		},
1107 		.driver_data = (void *)&i8k_config_data[DELL_STUDIO],
1108 	},
1109 	{
1110 		.ident = "Dell XPS M140",
1111 		.matches = {
1112 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1113 			DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
1114 		},
1115 		.driver_data = (void *)&i8k_config_data[DELL_XPS],
1116 	},
1117 	{
1118 		.ident = "Dell XPS",
1119 		.matches = {
1120 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1121 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS"),
1122 		},
1123 	},
1124 	{ }
1125 };
1126 
1127 MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
1128 
1129 /*
1130  * On some machines once I8K_SMM_GET_FAN_TYPE is issued then CPU fan speed
1131  * randomly going up and down due to bug in Dell SMM or BIOS. Here is blacklist
1132  * of affected Dell machines for which we disallow I8K_SMM_GET_FAN_TYPE call.
1133  * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=100121
1134  */
1135 static const struct dmi_system_id i8k_blacklist_fan_type_dmi_table[] __initconst = {
1136 	{
1137 		.ident = "Dell Studio XPS 8000",
1138 		.matches = {
1139 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1140 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8000"),
1141 		},
1142 	},
1143 	{
1144 		.ident = "Dell Studio XPS 8100",
1145 		.matches = {
1146 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1147 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8100"),
1148 		},
1149 	},
1150 	{
1151 		.ident = "Dell Inspiron 580",
1152 		.matches = {
1153 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1154 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 580 "),
1155 		},
1156 	},
1157 	{ }
1158 };
1159 
1160 /*
1161  * On some machines all fan related SMM functions implemented by Dell BIOS
1162  * firmware freeze kernel for about 500ms. Until Dell fixes these problems fan
1163  * support for affected blacklisted Dell machines stay disabled.
1164  * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=195751
1165  */
1166 static const struct dmi_system_id i8k_blacklist_fan_support_dmi_table[] __initconst = {
1167 	{
1168 		.ident = "Dell Inspiron 7720",
1169 		.matches = {
1170 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1171 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 7720"),
1172 		},
1173 	},
1174 	{
1175 		.ident = "Dell Vostro 3360",
1176 		.matches = {
1177 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1178 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Vostro 3360"),
1179 		},
1180 	},
1181 	{
1182 		.ident = "Dell XPS13 9333",
1183 		.matches = {
1184 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1185 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS13 9333"),
1186 		},
1187 	},
1188 	{
1189 		.ident = "Dell XPS 15 L502X",
1190 		.matches = {
1191 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1192 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L502X"),
1193 		},
1194 	},
1195 	{ }
1196 };
1197 
1198 struct i8k_fan_control_data {
1199 	unsigned int manual_fan;
1200 	unsigned int auto_fan;
1201 };
1202 
1203 enum i8k_fan_controls {
1204 	I8K_FAN_34A3_35A3,
1205 };
1206 
1207 static const struct i8k_fan_control_data i8k_fan_control_data[] __initconst = {
1208 	[I8K_FAN_34A3_35A3] = {
1209 		.manual_fan = 0x34a3,
1210 		.auto_fan = 0x35a3,
1211 	},
1212 };
1213 
1214 static const struct dmi_system_id i8k_whitelist_fan_control[] __initconst = {
1215 	{
1216 		.ident = "Dell Latitude 5480",
1217 		.matches = {
1218 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1219 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude 5480"),
1220 		},
1221 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1222 	},
1223 	{
1224 		.ident = "Dell Latitude E6440",
1225 		.matches = {
1226 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1227 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E6440"),
1228 		},
1229 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1230 	},
1231 	{
1232 		.ident = "Dell Latitude E7440",
1233 		.matches = {
1234 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1235 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E7440"),
1236 		},
1237 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1238 	},
1239 	{
1240 		.ident = "Dell Precision 5530",
1241 		.matches = {
1242 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1243 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 5530"),
1244 		},
1245 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1246 	},
1247 	{
1248 		.ident = "Dell Precision 7510",
1249 		.matches = {
1250 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1251 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
1252 		},
1253 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1254 	},
1255 	{ }
1256 };
1257 
1258 static int __init dell_smm_probe(struct platform_device *pdev)
1259 {
1260 	struct dell_smm_data *data;
1261 	const struct dmi_system_id *id, *fan_control;
1262 	int fan, ret;
1263 
1264 	data = devm_kzalloc(&pdev->dev, sizeof(struct dell_smm_data), GFP_KERNEL);
1265 	if (!data)
1266 		return -ENOMEM;
1267 
1268 	mutex_init(&data->i8k_mutex);
1269 	data->i8k_fan_mult = I8K_FAN_MULT;
1270 	data->i8k_fan_max = I8K_FAN_HIGH;
1271 	platform_set_drvdata(pdev, data);
1272 
1273 	if (dmi_check_system(i8k_blacklist_fan_support_dmi_table)) {
1274 		dev_warn(&pdev->dev, "broken Dell BIOS detected, disallow fan support\n");
1275 		if (!force)
1276 			data->disallow_fan_support = true;
1277 	}
1278 
1279 	if (dmi_check_system(i8k_blacklist_fan_type_dmi_table)) {
1280 		dev_warn(&pdev->dev, "broken Dell BIOS detected, disallow fan type call\n");
1281 		if (!force)
1282 			data->disallow_fan_type_call = true;
1283 	}
1284 
1285 	strscpy(data->bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
1286 		sizeof(data->bios_version));
1287 	strscpy(data->bios_machineid, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
1288 		sizeof(data->bios_machineid));
1289 
1290 	/*
1291 	 * Set fan multiplier and maximal fan speed from dmi config
1292 	 * Values specified in module parameters override values from dmi
1293 	 */
1294 	id = dmi_first_match(i8k_dmi_table);
1295 	if (id && id->driver_data) {
1296 		const struct i8k_config_data *conf = id->driver_data;
1297 
1298 		if (!fan_mult && conf->fan_mult)
1299 			fan_mult = conf->fan_mult;
1300 
1301 		if (!fan_max && conf->fan_max)
1302 			fan_max = conf->fan_max;
1303 	}
1304 
1305 	data->i8k_fan_max = fan_max ? : I8K_FAN_HIGH;	/* Must not be 0 */
1306 	data->i8k_pwm_mult = DIV_ROUND_UP(255, data->i8k_fan_max);
1307 
1308 	fan_control = dmi_first_match(i8k_whitelist_fan_control);
1309 	if (fan_control && fan_control->driver_data) {
1310 		const struct i8k_fan_control_data *control = fan_control->driver_data;
1311 
1312 		data->manual_fan = control->manual_fan;
1313 		data->auto_fan = control->auto_fan;
1314 		dev_info(&pdev->dev, "enabling support for setting automatic/manual fan control\n");
1315 	}
1316 
1317 	if (!fan_mult) {
1318 		/*
1319 		 * Autodetect fan multiplier based on nominal rpm
1320 		 * If fan reports rpm value too high then set multiplier to 1
1321 		 */
1322 		for (fan = 0; fan < DELL_SMM_NO_FANS; ++fan) {
1323 			ret = i8k_get_fan_nominal_speed(data, fan, data->i8k_fan_max);
1324 			if (ret < 0)
1325 				continue;
1326 
1327 			if (ret > I8K_FAN_MAX_RPM)
1328 				data->i8k_fan_mult = 1;
1329 			break;
1330 		}
1331 	} else {
1332 		/* Fan multiplier was specified in module param or in dmi */
1333 		data->i8k_fan_mult = fan_mult;
1334 	}
1335 
1336 	ret = dell_smm_init_hwmon(&pdev->dev);
1337 	if (ret)
1338 		return ret;
1339 
1340 	i8k_init_procfs(&pdev->dev);
1341 
1342 	return 0;
1343 }
1344 
1345 static struct platform_driver dell_smm_driver = {
1346 	.driver		= {
1347 		.name	= KBUILD_MODNAME,
1348 	},
1349 };
1350 
1351 static struct platform_device *dell_smm_device;
1352 
1353 /*
1354  * Probe for the presence of a supported laptop.
1355  */
1356 static int __init i8k_init(void)
1357 {
1358 	/*
1359 	 * Get DMI information
1360 	 */
1361 	if (!dmi_check_system(i8k_dmi_table)) {
1362 		if (!ignore_dmi && !force)
1363 			return -ENODEV;
1364 
1365 		pr_info("not running on a supported Dell system.\n");
1366 		pr_info("vendor=%s, model=%s, version=%s\n",
1367 			i8k_get_dmi_data(DMI_SYS_VENDOR),
1368 			i8k_get_dmi_data(DMI_PRODUCT_NAME),
1369 			i8k_get_dmi_data(DMI_BIOS_VERSION));
1370 	}
1371 
1372 	/*
1373 	 * Get SMM Dell signature
1374 	 */
1375 	if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
1376 	    i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
1377 		pr_err("unable to get SMM Dell signature\n");
1378 		if (!force)
1379 			return -ENODEV;
1380 	}
1381 
1382 	dell_smm_device = platform_create_bundle(&dell_smm_driver, dell_smm_probe, NULL, 0, NULL,
1383 						 0);
1384 
1385 	return PTR_ERR_OR_ZERO(dell_smm_device);
1386 }
1387 
1388 static void __exit i8k_exit(void)
1389 {
1390 	platform_device_unregister(dell_smm_device);
1391 	platform_driver_unregister(&dell_smm_driver);
1392 }
1393 
1394 module_init(i8k_init);
1395 module_exit(i8k_exit);
1396