xref: /linux/drivers/hwmon/dell-smm-hwmon.c (revision 71dfa617ea9f18e4585fe78364217cd32b1fc382)
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/acpi.h>
16 #include <linux/capability.h>
17 #include <linux/cpu.h>
18 #include <linux/ctype.h>
19 #include <linux/delay.h>
20 #include <linux/dmi.h>
21 #include <linux/err.h>
22 #include <linux/errno.h>
23 #include <linux/hwmon.h>
24 #include <linux/init.h>
25 #include <linux/kconfig.h>
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/mutex.h>
29 #include <linux/platform_device.h>
30 #include <linux/proc_fs.h>
31 #include <linux/seq_file.h>
32 #include <linux/slab.h>
33 #include <linux/smp.h>
34 #include <linux/string.h>
35 #include <linux/thermal.h>
36 #include <linux/types.h>
37 #include <linux/uaccess.h>
38 #include <linux/wmi.h>
39 
40 #include <linux/i8k.h>
41 #include <asm/unaligned.h>
42 
43 #define I8K_SMM_FN_STATUS	0x0025
44 #define I8K_SMM_POWER_STATUS	0x0069
45 #define I8K_SMM_SET_FAN		0x01a3
46 #define I8K_SMM_GET_FAN		0x00a3
47 #define I8K_SMM_GET_SPEED	0x02a3
48 #define I8K_SMM_GET_FAN_TYPE	0x03a3
49 #define I8K_SMM_GET_NOM_SPEED	0x04a3
50 #define I8K_SMM_GET_TEMP	0x10a3
51 #define I8K_SMM_GET_TEMP_TYPE	0x11a3
52 #define I8K_SMM_GET_DELL_SIG1	0xfea3
53 #define I8K_SMM_GET_DELL_SIG2	0xffa3
54 
55 /* in usecs */
56 #define DELL_SMM_MAX_DURATION  250000
57 
58 #define I8K_FAN_MULT		30
59 #define I8K_FAN_RPM_THRESHOLD	1000
60 #define I8K_MAX_TEMP		127
61 
62 #define I8K_FN_NONE		0x00
63 #define I8K_FN_UP		0x01
64 #define I8K_FN_DOWN		0x02
65 #define I8K_FN_MUTE		0x04
66 #define I8K_FN_MASK		0x07
67 #define I8K_FN_SHIFT		8
68 
69 #define I8K_POWER_AC		0x05
70 #define I8K_POWER_BATTERY	0x01
71 
72 #define DELL_SMM_WMI_GUID	"F1DDEE52-063C-4784-A11E-8A06684B9B01"
73 #define DELL_SMM_LEGACY_EXECUTE	0x1
74 
75 #define DELL_SMM_NO_TEMP	10
76 #define DELL_SMM_NO_FANS	3
77 
78 struct smm_regs {
79 	unsigned int eax;
80 	unsigned int ebx;
81 	unsigned int ecx;
82 	unsigned int edx;
83 	unsigned int esi;
84 	unsigned int edi;
85 };
86 
87 struct dell_smm_ops {
88 	struct device *smm_dev;
89 	int (*smm_call)(struct device *smm_dev, struct smm_regs *regs);
90 };
91 
92 struct dell_smm_data {
93 	struct mutex i8k_mutex; /* lock for sensors writes */
94 	char bios_version[4];
95 	char bios_machineid[16];
96 	uint i8k_fan_mult;
97 	uint i8k_pwm_mult;
98 	uint i8k_fan_max;
99 	int temp_type[DELL_SMM_NO_TEMP];
100 	bool fan[DELL_SMM_NO_FANS];
101 	int fan_type[DELL_SMM_NO_FANS];
102 	int *fan_nominal_speed[DELL_SMM_NO_FANS];
103 	const struct dell_smm_ops *ops;
104 };
105 
106 struct dell_smm_cooling_data {
107 	u8 fan_num;
108 	struct dell_smm_data *data;
109 };
110 
111 MODULE_AUTHOR("Massimo Dal Zotto <dz@debian.org>");
112 MODULE_AUTHOR("Pali Rohár <pali@kernel.org>");
113 MODULE_DESCRIPTION("Dell laptop SMM BIOS hwmon driver");
114 MODULE_LICENSE("GPL");
115 MODULE_ALIAS("i8k");
116 
117 static bool force;
118 module_param_unsafe(force, bool, 0);
119 MODULE_PARM_DESC(force, "Force loading without checking for supported models and features");
120 
121 static bool ignore_dmi;
122 module_param(ignore_dmi, bool, 0);
123 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
124 
125 #if IS_ENABLED(CONFIG_I8K)
126 static bool restricted = true;
127 module_param(restricted, bool, 0);
128 MODULE_PARM_DESC(restricted, "Restrict fan control and serial number to CAP_SYS_ADMIN (default: 1)");
129 
130 static bool power_status;
131 module_param(power_status, bool, 0600);
132 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k (default: 0)");
133 #endif
134 
135 static uint fan_mult;
136 module_param(fan_mult, uint, 0);
137 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with (default: autodetect)");
138 
139 static uint fan_max;
140 module_param(fan_max, uint, 0);
141 MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autodetect)");
142 
143 static bool disallow_fan_type_call, disallow_fan_support;
144 
145 static unsigned int manual_fan, auto_fan;
146 
147 static const char * const temp_labels[] = {
148 	"CPU",
149 	"GPU",
150 	"SODIMM",
151 	"Other",
152 	"Ambient",
153 	"Other",
154 };
155 
156 static const char * const fan_labels[] = {
157 	"Processor Fan",
158 	"Motherboard Fan",
159 	"Video Fan",
160 	"Power Supply Fan",
161 	"Chipset Fan",
162 	"Other Fan",
163 };
164 
165 static const char * const docking_labels[] = {
166 	"Docking Processor Fan",
167 	"Docking Motherboard Fan",
168 	"Docking Video Fan",
169 	"Docking Power Supply Fan",
170 	"Docking Chipset Fan",
171 	"Docking Other Fan",
172 };
173 
174 static inline const char __init *i8k_get_dmi_data(int field)
175 {
176 	const char *dmi_data = dmi_get_system_info(field);
177 
178 	return dmi_data && *dmi_data ? dmi_data : "?";
179 }
180 
181 /*
182  * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
183  */
184 static int i8k_smm_func(void *par)
185 {
186 	struct smm_regs *regs = par;
187 	unsigned char carry;
188 
189 	/* SMM requires CPU 0 */
190 	if (smp_processor_id() != 0)
191 		return -EBUSY;
192 
193 	asm volatile("out %%al,$0xb2\n\t"
194 		     "out %%al,$0x84\n\t"
195 		     "setc %0\n"
196 		     : "=mr" (carry),
197 		       "+a" (regs->eax),
198 		       "+b" (regs->ebx),
199 		       "+c" (regs->ecx),
200 		       "+d" (regs->edx),
201 		       "+S" (regs->esi),
202 		       "+D" (regs->edi));
203 
204 	if (carry)
205 		return -EINVAL;
206 
207 	return 0;
208 }
209 
210 /*
211  * Call the System Management Mode BIOS.
212  */
213 static int i8k_smm_call(struct device *dummy, struct smm_regs *regs)
214 {
215 	int ret;
216 
217 	cpus_read_lock();
218 	ret = smp_call_on_cpu(0, i8k_smm_func, regs, true);
219 	cpus_read_unlock();
220 
221 	return ret;
222 }
223 
224 static const struct dell_smm_ops i8k_smm_ops = {
225 	.smm_call = i8k_smm_call,
226 };
227 
228 /*
229  * Call the System Management Mode BIOS over WMI.
230  */
231 static ssize_t wmi_parse_register(u8 *buffer, u32 length, unsigned int *reg)
232 {
233 	__le32 value;
234 	u32 reg_size;
235 
236 	if (length <= sizeof(reg_size))
237 		return -ENODATA;
238 
239 	reg_size = get_unaligned_le32(buffer);
240 	if (!reg_size || reg_size > sizeof(value))
241 		return -ENOMSG;
242 
243 	if (length < sizeof(reg_size) + reg_size)
244 		return -ENODATA;
245 
246 	memcpy_and_pad(&value, sizeof(value), buffer + sizeof(reg_size), reg_size, 0);
247 	*reg = le32_to_cpu(value);
248 
249 	return reg_size + sizeof(reg_size);
250 }
251 
252 static int wmi_parse_response(u8 *buffer, u32 length, struct smm_regs *regs)
253 {
254 	unsigned int *registers[] = {
255 		&regs->eax,
256 		&regs->ebx,
257 		&regs->ecx,
258 		&regs->edx
259 	};
260 	u32 offset = 0;
261 	ssize_t ret;
262 	int i;
263 
264 	for (i = 0; i < ARRAY_SIZE(registers); i++) {
265 		if (offset >= length)
266 			return -ENODATA;
267 
268 		ret = wmi_parse_register(buffer + offset, length - offset, registers[i]);
269 		if (ret < 0)
270 			return ret;
271 
272 		offset += ret;
273 	}
274 
275 	if (offset != length)
276 		return -ENOMSG;
277 
278 	return 0;
279 }
280 
281 static int wmi_smm_call(struct device *dev, struct smm_regs *regs)
282 {
283 	struct wmi_device *wdev = container_of(dev, struct wmi_device, dev);
284 	struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
285 	u32 wmi_payload[] = {
286 		sizeof(regs->eax),
287 		regs->eax,
288 		sizeof(regs->ebx),
289 		regs->ebx,
290 		sizeof(regs->ecx),
291 		regs->ecx,
292 		sizeof(regs->edx),
293 		regs->edx
294 	};
295 	const struct acpi_buffer in = {
296 		.length = sizeof(wmi_payload),
297 		.pointer = &wmi_payload,
298 	};
299 	union acpi_object *obj;
300 	acpi_status status;
301 	int ret;
302 
303 	status = wmidev_evaluate_method(wdev, 0x0, DELL_SMM_LEGACY_EXECUTE, &in, &out);
304 	if (ACPI_FAILURE(status))
305 		return -EIO;
306 
307 	obj = out.pointer;
308 	if (!obj)
309 		return -ENODATA;
310 
311 	if (obj->type != ACPI_TYPE_BUFFER) {
312 		ret = -ENOMSG;
313 
314 		goto err_free;
315 	}
316 
317 	ret = wmi_parse_response(obj->buffer.pointer, obj->buffer.length, regs);
318 
319 err_free:
320 	kfree(obj);
321 
322 	return ret;
323 }
324 
325 static int dell_smm_call(const struct dell_smm_ops *ops, struct smm_regs *regs)
326 {
327 	unsigned int eax = regs->eax;
328 	unsigned int ebx = regs->ebx;
329 	long long duration;
330 	ktime_t calltime;
331 	int ret;
332 
333 	calltime = ktime_get();
334 	ret = ops->smm_call(ops->smm_dev, regs);
335 	duration = ktime_us_delta(ktime_get(), calltime);
336 
337 	pr_debug("SMM(0x%.4x 0x%.4x) = 0x%.4x status: %d (took %7lld usecs)\n",
338 		 eax, ebx, regs->eax & 0xffff, ret, duration);
339 
340 	if (duration > DELL_SMM_MAX_DURATION)
341 		pr_warn_once("SMM call took %lld usecs!\n", duration);
342 
343 	if (ret < 0)
344 		return ret;
345 
346 	if ((regs->eax & 0xffff) == 0xffff || regs->eax == eax)
347 		return -EINVAL;
348 
349 	return 0;
350 }
351 
352 /*
353  * Read the fan status.
354  */
355 static int i8k_get_fan_status(const struct dell_smm_data *data, u8 fan)
356 {
357 	struct smm_regs regs = {
358 		.eax = I8K_SMM_GET_FAN,
359 		.ebx = fan,
360 	};
361 
362 	if (disallow_fan_support)
363 		return -EINVAL;
364 
365 	return dell_smm_call(data->ops, &regs) ? : regs.eax & 0xff;
366 }
367 
368 /*
369  * Read the fan speed in RPM.
370  */
371 static int i8k_get_fan_speed(const struct dell_smm_data *data, u8 fan)
372 {
373 	struct smm_regs regs = {
374 		.eax = I8K_SMM_GET_SPEED,
375 		.ebx = fan,
376 	};
377 
378 	if (disallow_fan_support)
379 		return -EINVAL;
380 
381 	return dell_smm_call(data->ops, &regs) ? : (regs.eax & 0xffff) * data->i8k_fan_mult;
382 }
383 
384 /*
385  * Read the fan type.
386  */
387 static int _i8k_get_fan_type(const struct dell_smm_data *data, u8 fan)
388 {
389 	struct smm_regs regs = {
390 		.eax = I8K_SMM_GET_FAN_TYPE,
391 		.ebx = fan,
392 	};
393 
394 	if (disallow_fan_support || disallow_fan_type_call)
395 		return -EINVAL;
396 
397 	return dell_smm_call(data->ops, &regs) ? : regs.eax & 0xff;
398 }
399 
400 static int i8k_get_fan_type(struct dell_smm_data *data, u8 fan)
401 {
402 	/* I8K_SMM_GET_FAN_TYPE SMM call is expensive, so cache values */
403 	if (data->fan_type[fan] == INT_MIN)
404 		data->fan_type[fan] = _i8k_get_fan_type(data, fan);
405 
406 	return data->fan_type[fan];
407 }
408 
409 /*
410  * Read the fan nominal rpm for specific fan speed.
411  */
412 static int i8k_get_fan_nominal_speed(const struct dell_smm_data *data, u8 fan, int speed)
413 {
414 	struct smm_regs regs = {
415 		.eax = I8K_SMM_GET_NOM_SPEED,
416 		.ebx = fan | (speed << 8),
417 	};
418 
419 	if (disallow_fan_support)
420 		return -EINVAL;
421 
422 	return dell_smm_call(data->ops, &regs) ? : (regs.eax & 0xffff);
423 }
424 
425 /*
426  * Enable or disable automatic BIOS fan control support
427  */
428 static int i8k_enable_fan_auto_mode(const struct dell_smm_data *data, bool enable)
429 {
430 	struct smm_regs regs = { };
431 
432 	if (disallow_fan_support)
433 		return -EINVAL;
434 
435 	regs.eax = enable ? auto_fan : manual_fan;
436 	return dell_smm_call(data->ops, &regs);
437 }
438 
439 /*
440  * Set the fan speed (off, low, high, ...).
441  */
442 static int i8k_set_fan(const struct dell_smm_data *data, u8 fan, int speed)
443 {
444 	struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
445 
446 	if (disallow_fan_support)
447 		return -EINVAL;
448 
449 	speed = (speed < 0) ? 0 : ((speed > data->i8k_fan_max) ? data->i8k_fan_max : speed);
450 	regs.ebx = fan | (speed << 8);
451 
452 	return dell_smm_call(data->ops, &regs);
453 }
454 
455 static int i8k_get_temp_type(const struct dell_smm_data *data, u8 sensor)
456 {
457 	struct smm_regs regs = {
458 		.eax = I8K_SMM_GET_TEMP_TYPE,
459 		.ebx = sensor,
460 	};
461 
462 	return dell_smm_call(data->ops, &regs) ? : regs.eax & 0xff;
463 }
464 
465 /*
466  * Read the cpu temperature.
467  */
468 static int _i8k_get_temp(const struct dell_smm_data *data, u8 sensor)
469 {
470 	struct smm_regs regs = {
471 		.eax = I8K_SMM_GET_TEMP,
472 		.ebx = sensor,
473 	};
474 
475 	return dell_smm_call(data->ops, &regs) ? : regs.eax & 0xff;
476 }
477 
478 static int i8k_get_temp(const struct dell_smm_data *data, u8 sensor)
479 {
480 	int temp = _i8k_get_temp(data, sensor);
481 
482 	/*
483 	 * Sometimes the temperature sensor returns 0x99, which is out of range.
484 	 * In this case we retry (once) before returning an error.
485 	 # 1003655137 00000058 00005a4b
486 	 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
487 	 # 1003655139 00000054 00005c52
488 	 */
489 	if (temp == 0x99) {
490 		msleep(100);
491 		temp = _i8k_get_temp(data, sensor);
492 	}
493 	/*
494 	 * Return -ENODATA for all invalid temperatures.
495 	 *
496 	 * Known instances are the 0x99 value as seen above as well as
497 	 * 0xc1 (193), which may be returned when trying to read the GPU
498 	 * temperature if the system supports a GPU and it is currently
499 	 * turned off.
500 	 */
501 	if (temp > I8K_MAX_TEMP)
502 		return -ENODATA;
503 
504 	return temp;
505 }
506 
507 static int dell_smm_get_signature(const struct dell_smm_ops *ops, int req_fn)
508 {
509 	struct smm_regs regs = { .eax = req_fn, };
510 	int rc;
511 
512 	rc = dell_smm_call(ops, &regs);
513 	if (rc < 0)
514 		return rc;
515 
516 	return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
517 }
518 
519 #if IS_ENABLED(CONFIG_I8K)
520 
521 /*
522  * Read the Fn key status.
523  */
524 static int i8k_get_fn_status(const struct dell_smm_data *data)
525 {
526 	struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
527 	int rc;
528 
529 	rc = dell_smm_call(data->ops, &regs);
530 	if (rc < 0)
531 		return rc;
532 
533 	switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
534 	case I8K_FN_UP:
535 		return I8K_VOL_UP;
536 	case I8K_FN_DOWN:
537 		return I8K_VOL_DOWN;
538 	case I8K_FN_MUTE:
539 		return I8K_VOL_MUTE;
540 	default:
541 		return 0;
542 	}
543 }
544 
545 /*
546  * Read the power status.
547  */
548 static int i8k_get_power_status(const struct dell_smm_data *data)
549 {
550 	struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
551 	int rc;
552 
553 	rc = dell_smm_call(data->ops, &regs);
554 	if (rc < 0)
555 		return rc;
556 
557 	return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
558 }
559 
560 /*
561  * Procfs interface
562  */
563 
564 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
565 {
566 	struct dell_smm_data *data = pde_data(file_inode(fp));
567 	int __user *argp = (int __user *)arg;
568 	int speed, err;
569 	int val = 0;
570 
571 	if (!argp)
572 		return -EINVAL;
573 
574 	switch (cmd) {
575 	case I8K_BIOS_VERSION:
576 		if (!isdigit(data->bios_version[0]) || !isdigit(data->bios_version[1]) ||
577 		    !isdigit(data->bios_version[2]))
578 			return -EINVAL;
579 
580 		val = (data->bios_version[0] << 16) |
581 				(data->bios_version[1] << 8) | data->bios_version[2];
582 
583 		if (copy_to_user(argp, &val, sizeof(val)))
584 			return -EFAULT;
585 
586 		return 0;
587 	case I8K_MACHINE_ID:
588 		if (restricted && !capable(CAP_SYS_ADMIN))
589 			return -EPERM;
590 
591 		if (copy_to_user(argp, data->bios_machineid, sizeof(data->bios_machineid)))
592 			return -EFAULT;
593 
594 		return 0;
595 	case I8K_FN_STATUS:
596 		val = i8k_get_fn_status(data);
597 		break;
598 
599 	case I8K_POWER_STATUS:
600 		val = i8k_get_power_status(data);
601 		break;
602 
603 	case I8K_GET_TEMP:
604 		val = i8k_get_temp(data, 0);
605 		break;
606 
607 	case I8K_GET_SPEED:
608 		if (copy_from_user(&val, argp, sizeof(int)))
609 			return -EFAULT;
610 
611 		if (val > U8_MAX || val < 0)
612 			return -EINVAL;
613 
614 		val = i8k_get_fan_speed(data, val);
615 		break;
616 
617 	case I8K_GET_FAN:
618 		if (copy_from_user(&val, argp, sizeof(int)))
619 			return -EFAULT;
620 
621 		if (val > U8_MAX || val < 0)
622 			return -EINVAL;
623 
624 		val = i8k_get_fan_status(data, val);
625 		break;
626 
627 	case I8K_SET_FAN:
628 		if (restricted && !capable(CAP_SYS_ADMIN))
629 			return -EPERM;
630 
631 		if (copy_from_user(&val, argp, sizeof(int)))
632 			return -EFAULT;
633 
634 		if (val > U8_MAX || val < 0)
635 			return -EINVAL;
636 
637 		if (copy_from_user(&speed, argp + 1, sizeof(int)))
638 			return -EFAULT;
639 
640 		mutex_lock(&data->i8k_mutex);
641 		err = i8k_set_fan(data, val, speed);
642 		if (err < 0)
643 			val = err;
644 		else
645 			val = i8k_get_fan_status(data, val);
646 		mutex_unlock(&data->i8k_mutex);
647 		break;
648 
649 	default:
650 		return -ENOIOCTLCMD;
651 	}
652 
653 	if (val < 0)
654 		return val;
655 
656 	if (copy_to_user(argp, &val, sizeof(int)))
657 		return -EFAULT;
658 
659 	return 0;
660 }
661 
662 /*
663  * Print the information for /proc/i8k.
664  */
665 static int i8k_proc_show(struct seq_file *seq, void *offset)
666 {
667 	struct dell_smm_data *data = seq->private;
668 	int fn_key, cpu_temp, ac_power;
669 	int left_fan, right_fan, left_speed, right_speed;
670 
671 	cpu_temp	= i8k_get_temp(data, 0);			/* 11100 µs */
672 	left_fan	= i8k_get_fan_status(data, I8K_FAN_LEFT);	/*   580 µs */
673 	right_fan	= i8k_get_fan_status(data, I8K_FAN_RIGHT);	/*   580 µs */
674 	left_speed	= i8k_get_fan_speed(data, I8K_FAN_LEFT);	/*   580 µs */
675 	right_speed	= i8k_get_fan_speed(data, I8K_FAN_RIGHT);	/*   580 µs */
676 	fn_key		= i8k_get_fn_status(data);			/*   750 µs */
677 	if (power_status)
678 		ac_power = i8k_get_power_status(data);			/* 14700 µs */
679 	else
680 		ac_power = -1;
681 
682 	/*
683 	 * Info:
684 	 *
685 	 * 1)  Format version (this will change if format changes)
686 	 * 2)  BIOS version
687 	 * 3)  BIOS machine ID
688 	 * 4)  Cpu temperature
689 	 * 5)  Left fan status
690 	 * 6)  Right fan status
691 	 * 7)  Left fan speed
692 	 * 8)  Right fan speed
693 	 * 9)  AC power
694 	 * 10) Fn Key status
695 	 */
696 	seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
697 		   I8K_PROC_FMT,
698 		   data->bios_version,
699 		   (restricted && !capable(CAP_SYS_ADMIN)) ? "-1" : data->bios_machineid,
700 		   cpu_temp,
701 		   left_fan, right_fan, left_speed, right_speed,
702 		   ac_power, fn_key);
703 
704 	return 0;
705 }
706 
707 static int i8k_open_fs(struct inode *inode, struct file *file)
708 {
709 	return single_open(file, i8k_proc_show, pde_data(inode));
710 }
711 
712 static const struct proc_ops i8k_proc_ops = {
713 	.proc_open	= i8k_open_fs,
714 	.proc_read	= seq_read,
715 	.proc_lseek	= seq_lseek,
716 	.proc_release	= single_release,
717 	.proc_ioctl	= i8k_ioctl,
718 };
719 
720 static void i8k_exit_procfs(void *param)
721 {
722 	remove_proc_entry("i8k", NULL);
723 }
724 
725 static void __init i8k_init_procfs(struct device *dev)
726 {
727 	struct dell_smm_data *data = dev_get_drvdata(dev);
728 
729 	strscpy(data->bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
730 		sizeof(data->bios_version));
731 	strscpy(data->bios_machineid, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
732 		sizeof(data->bios_machineid));
733 
734 	/* Only register exit function if creation was successful */
735 	if (proc_create_data("i8k", 0, NULL, &i8k_proc_ops, data))
736 		devm_add_action_or_reset(dev, i8k_exit_procfs, NULL);
737 }
738 
739 #else
740 
741 static void __init i8k_init_procfs(struct device *dev)
742 {
743 }
744 
745 #endif
746 
747 static int dell_smm_get_max_state(struct thermal_cooling_device *dev, unsigned long *state)
748 {
749 	struct dell_smm_cooling_data *cdata = dev->devdata;
750 
751 	*state = cdata->data->i8k_fan_max;
752 
753 	return 0;
754 }
755 
756 static int dell_smm_get_cur_state(struct thermal_cooling_device *dev, unsigned long *state)
757 {
758 	struct dell_smm_cooling_data *cdata = dev->devdata;
759 	int ret;
760 
761 	ret = i8k_get_fan_status(cdata->data, cdata->fan_num);
762 	if (ret < 0)
763 		return ret;
764 
765 	*state = ret;
766 
767 	return 0;
768 }
769 
770 static int dell_smm_set_cur_state(struct thermal_cooling_device *dev, unsigned long state)
771 {
772 	struct dell_smm_cooling_data *cdata = dev->devdata;
773 	struct dell_smm_data *data = cdata->data;
774 	int ret;
775 
776 	if (state > data->i8k_fan_max)
777 		return -EINVAL;
778 
779 	mutex_lock(&data->i8k_mutex);
780 	ret = i8k_set_fan(data, cdata->fan_num, (int)state);
781 	mutex_unlock(&data->i8k_mutex);
782 
783 	return ret;
784 }
785 
786 static const struct thermal_cooling_device_ops dell_smm_cooling_ops = {
787 	.get_max_state = dell_smm_get_max_state,
788 	.get_cur_state = dell_smm_get_cur_state,
789 	.set_cur_state = dell_smm_set_cur_state,
790 };
791 
792 static umode_t dell_smm_is_visible(const void *drvdata, enum hwmon_sensor_types type, u32 attr,
793 				   int channel)
794 {
795 	const struct dell_smm_data *data = drvdata;
796 
797 	switch (type) {
798 	case hwmon_temp:
799 		switch (attr) {
800 		case hwmon_temp_input:
801 			/* _i8k_get_temp() is fine since we do not care about the actual value */
802 			if (data->temp_type[channel] >= 0 || _i8k_get_temp(data, channel) >= 0)
803 				return 0444;
804 
805 			break;
806 		case hwmon_temp_label:
807 			if (data->temp_type[channel] >= 0)
808 				return 0444;
809 
810 			break;
811 		default:
812 			break;
813 		}
814 		break;
815 	case hwmon_fan:
816 		if (disallow_fan_support)
817 			break;
818 
819 		switch (attr) {
820 		case hwmon_fan_input:
821 			if (data->fan[channel])
822 				return 0444;
823 
824 			break;
825 		case hwmon_fan_label:
826 			if (data->fan[channel] && !disallow_fan_type_call)
827 				return 0444;
828 
829 			break;
830 		case hwmon_fan_min:
831 		case hwmon_fan_max:
832 		case hwmon_fan_target:
833 			if (data->fan_nominal_speed[channel])
834 				return 0444;
835 
836 			break;
837 		default:
838 			break;
839 		}
840 		break;
841 	case hwmon_pwm:
842 		if (disallow_fan_support)
843 			break;
844 
845 		switch (attr) {
846 		case hwmon_pwm_input:
847 			if (data->fan[channel])
848 				return 0644;
849 
850 			break;
851 		case hwmon_pwm_enable:
852 			if (auto_fan)
853 				/*
854 				 * There is no command for retrieve the current status
855 				 * from BIOS, and userspace/firmware itself can change
856 				 * it.
857 				 * Thus we can only provide write-only access for now.
858 				 */
859 				return 0200;
860 
861 			break;
862 		default:
863 			break;
864 		}
865 		break;
866 	default:
867 		break;
868 	}
869 
870 	return 0;
871 }
872 
873 static int dell_smm_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
874 			 long *val)
875 {
876 	struct dell_smm_data *data = dev_get_drvdata(dev);
877 	int mult = data->i8k_fan_mult;
878 	int ret;
879 
880 	switch (type) {
881 	case hwmon_temp:
882 		switch (attr) {
883 		case hwmon_temp_input:
884 			ret = i8k_get_temp(data, channel);
885 			if (ret < 0)
886 				return ret;
887 
888 			*val = ret * 1000;
889 
890 			return 0;
891 		default:
892 			break;
893 		}
894 		break;
895 	case hwmon_fan:
896 		switch (attr) {
897 		case hwmon_fan_input:
898 			ret = i8k_get_fan_speed(data, channel);
899 			if (ret < 0)
900 				return ret;
901 
902 			*val = ret;
903 
904 			return 0;
905 		case hwmon_fan_min:
906 			*val = data->fan_nominal_speed[channel][0] * mult;
907 
908 			return 0;
909 		case hwmon_fan_max:
910 			*val = data->fan_nominal_speed[channel][data->i8k_fan_max] * mult;
911 
912 			return 0;
913 		case hwmon_fan_target:
914 			ret = i8k_get_fan_status(data, channel);
915 			if (ret < 0)
916 				return ret;
917 
918 			if (ret > data->i8k_fan_max)
919 				ret = data->i8k_fan_max;
920 
921 			*val = data->fan_nominal_speed[channel][ret] * mult;
922 
923 			return 0;
924 		default:
925 			break;
926 		}
927 		break;
928 	case hwmon_pwm:
929 		switch (attr) {
930 		case hwmon_pwm_input:
931 			ret = i8k_get_fan_status(data, channel);
932 			if (ret < 0)
933 				return ret;
934 
935 			*val = clamp_val(ret * data->i8k_pwm_mult, 0, 255);
936 
937 			return 0;
938 		default:
939 			break;
940 		}
941 		break;
942 	default:
943 		break;
944 	}
945 
946 	return -EOPNOTSUPP;
947 }
948 
949 static const char *dell_smm_fan_label(struct dell_smm_data *data, int channel)
950 {
951 	bool dock = false;
952 	int type = i8k_get_fan_type(data, channel);
953 
954 	if (type < 0)
955 		return ERR_PTR(type);
956 
957 	if (type & 0x10) {
958 		dock = true;
959 		type &= 0x0F;
960 	}
961 
962 	if (type >= ARRAY_SIZE(fan_labels))
963 		type = ARRAY_SIZE(fan_labels) - 1;
964 
965 	return dock ? docking_labels[type] : fan_labels[type];
966 }
967 
968 static int dell_smm_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
969 				int channel, const char **str)
970 {
971 	struct dell_smm_data *data = dev_get_drvdata(dev);
972 
973 	switch (type) {
974 	case hwmon_temp:
975 		switch (attr) {
976 		case hwmon_temp_label:
977 			*str = temp_labels[data->temp_type[channel]];
978 			return 0;
979 		default:
980 			break;
981 		}
982 		break;
983 	case hwmon_fan:
984 		switch (attr) {
985 		case hwmon_fan_label:
986 			*str = dell_smm_fan_label(data, channel);
987 			return PTR_ERR_OR_ZERO(*str);
988 		default:
989 			break;
990 		}
991 		break;
992 	default:
993 		break;
994 	}
995 
996 	return -EOPNOTSUPP;
997 }
998 
999 static int dell_smm_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
1000 			  long val)
1001 {
1002 	struct dell_smm_data *data = dev_get_drvdata(dev);
1003 	unsigned long pwm;
1004 	bool enable;
1005 	int err;
1006 
1007 	switch (type) {
1008 	case hwmon_pwm:
1009 		switch (attr) {
1010 		case hwmon_pwm_input:
1011 			pwm = clamp_val(DIV_ROUND_CLOSEST(val, data->i8k_pwm_mult), 0,
1012 					data->i8k_fan_max);
1013 
1014 			mutex_lock(&data->i8k_mutex);
1015 			err = i8k_set_fan(data, channel, pwm);
1016 			mutex_unlock(&data->i8k_mutex);
1017 
1018 			if (err < 0)
1019 				return err;
1020 
1021 			return 0;
1022 		case hwmon_pwm_enable:
1023 			if (!val)
1024 				return -EINVAL;
1025 
1026 			if (val == 1)
1027 				enable = false;
1028 			else
1029 				enable = true;
1030 
1031 			mutex_lock(&data->i8k_mutex);
1032 			err = i8k_enable_fan_auto_mode(data, enable);
1033 			mutex_unlock(&data->i8k_mutex);
1034 
1035 			if (err < 0)
1036 				return err;
1037 
1038 			return 0;
1039 		default:
1040 			break;
1041 		}
1042 		break;
1043 	default:
1044 		break;
1045 	}
1046 
1047 	return -EOPNOTSUPP;
1048 }
1049 
1050 static const struct hwmon_ops dell_smm_ops = {
1051 	.is_visible = dell_smm_is_visible,
1052 	.read = dell_smm_read,
1053 	.read_string = dell_smm_read_string,
1054 	.write = dell_smm_write,
1055 };
1056 
1057 static const struct hwmon_channel_info * const dell_smm_info[] = {
1058 	HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
1059 	HWMON_CHANNEL_INFO(temp,
1060 			   HWMON_T_INPUT | HWMON_T_LABEL,
1061 			   HWMON_T_INPUT | HWMON_T_LABEL,
1062 			   HWMON_T_INPUT | HWMON_T_LABEL,
1063 			   HWMON_T_INPUT | HWMON_T_LABEL,
1064 			   HWMON_T_INPUT | HWMON_T_LABEL,
1065 			   HWMON_T_INPUT | HWMON_T_LABEL,
1066 			   HWMON_T_INPUT | HWMON_T_LABEL,
1067 			   HWMON_T_INPUT | HWMON_T_LABEL,
1068 			   HWMON_T_INPUT | HWMON_T_LABEL,
1069 			   HWMON_T_INPUT | HWMON_T_LABEL
1070 			   ),
1071 	HWMON_CHANNEL_INFO(fan,
1072 			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
1073 			   HWMON_F_TARGET,
1074 			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
1075 			   HWMON_F_TARGET,
1076 			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
1077 			   HWMON_F_TARGET
1078 			   ),
1079 	HWMON_CHANNEL_INFO(pwm,
1080 			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
1081 			   HWMON_PWM_INPUT,
1082 			   HWMON_PWM_INPUT
1083 			   ),
1084 	NULL
1085 };
1086 
1087 static const struct hwmon_chip_info dell_smm_chip_info = {
1088 	.ops = &dell_smm_ops,
1089 	.info = dell_smm_info,
1090 };
1091 
1092 static int dell_smm_init_cdev(struct device *dev, u8 fan_num)
1093 {
1094 	struct dell_smm_data *data = dev_get_drvdata(dev);
1095 	struct thermal_cooling_device *cdev;
1096 	struct dell_smm_cooling_data *cdata;
1097 	int ret = 0;
1098 	char *name;
1099 
1100 	name = kasprintf(GFP_KERNEL, "dell-smm-fan%u", fan_num + 1);
1101 	if (!name)
1102 		return -ENOMEM;
1103 
1104 	cdata = devm_kmalloc(dev, sizeof(*cdata), GFP_KERNEL);
1105 	if (cdata) {
1106 		cdata->fan_num = fan_num;
1107 		cdata->data = data;
1108 		cdev = devm_thermal_of_cooling_device_register(dev, NULL, name, cdata,
1109 							       &dell_smm_cooling_ops);
1110 		if (IS_ERR(cdev)) {
1111 			devm_kfree(dev, cdata);
1112 			ret = PTR_ERR(cdev);
1113 		}
1114 	} else {
1115 		ret = -ENOMEM;
1116 	}
1117 
1118 	kfree(name);
1119 
1120 	return ret;
1121 }
1122 
1123 static int dell_smm_init_hwmon(struct device *dev)
1124 {
1125 	struct dell_smm_data *data = dev_get_drvdata(dev);
1126 	struct device *dell_smm_hwmon_dev;
1127 	int state, err;
1128 	u8 i;
1129 
1130 	for (i = 0; i < DELL_SMM_NO_TEMP; i++) {
1131 		data->temp_type[i] = i8k_get_temp_type(data, i);
1132 		if (data->temp_type[i] < 0)
1133 			continue;
1134 
1135 		if (data->temp_type[i] >= ARRAY_SIZE(temp_labels))
1136 			data->temp_type[i] = ARRAY_SIZE(temp_labels) - 1;
1137 	}
1138 
1139 	for (i = 0; i < DELL_SMM_NO_FANS; i++) {
1140 		data->fan_type[i] = INT_MIN;
1141 		err = i8k_get_fan_status(data, i);
1142 		if (err < 0)
1143 			err = i8k_get_fan_type(data, i);
1144 
1145 		if (err < 0)
1146 			continue;
1147 
1148 		data->fan[i] = true;
1149 
1150 		/* the cooling device is not critical, ignore failures */
1151 		if (IS_REACHABLE(CONFIG_THERMAL)) {
1152 			err = dell_smm_init_cdev(dev, i);
1153 			if (err < 0)
1154 				dev_warn(dev, "Failed to register cooling device for fan %u\n",
1155 					 i + 1);
1156 		}
1157 
1158 		data->fan_nominal_speed[i] = devm_kmalloc_array(dev, data->i8k_fan_max + 1,
1159 								sizeof(*data->fan_nominal_speed[i]),
1160 								GFP_KERNEL);
1161 		if (!data->fan_nominal_speed[i])
1162 			continue;
1163 
1164 		for (state = 0; state <= data->i8k_fan_max; state++) {
1165 			err = i8k_get_fan_nominal_speed(data, i, state);
1166 			if (err < 0) {
1167 				/* Mark nominal speed table as invalid in case of error */
1168 				devm_kfree(dev, data->fan_nominal_speed[i]);
1169 				data->fan_nominal_speed[i] = NULL;
1170 				break;
1171 			}
1172 			data->fan_nominal_speed[i][state] = err;
1173 			/*
1174 			 * Autodetect fan multiplier based on nominal rpm if multiplier
1175 			 * was not specified as module param or in DMI. If fan reports
1176 			 * rpm value too high then set multiplier to 1.
1177 			 */
1178 			if (!fan_mult && err > I8K_FAN_RPM_THRESHOLD)
1179 				data->i8k_fan_mult = 1;
1180 		}
1181 	}
1182 
1183 	dell_smm_hwmon_dev = devm_hwmon_device_register_with_info(dev, "dell_smm", data,
1184 								  &dell_smm_chip_info, NULL);
1185 
1186 	return PTR_ERR_OR_ZERO(dell_smm_hwmon_dev);
1187 }
1188 
1189 static int dell_smm_init_data(struct device *dev, const struct dell_smm_ops *ops)
1190 {
1191 	struct dell_smm_data *data;
1192 
1193 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
1194 	if (!data)
1195 		return -ENOMEM;
1196 
1197 	mutex_init(&data->i8k_mutex);
1198 	dev_set_drvdata(dev, data);
1199 
1200 	data->ops = ops;
1201 	/* All options must not be 0 */
1202 	data->i8k_fan_mult = fan_mult ? : I8K_FAN_MULT;
1203 	data->i8k_fan_max = fan_max ? : I8K_FAN_HIGH;
1204 	data->i8k_pwm_mult = DIV_ROUND_UP(255, data->i8k_fan_max);
1205 
1206 	return 0;
1207 }
1208 
1209 static const struct dmi_system_id i8k_dmi_table[] __initconst = {
1210 	{
1211 		.ident = "Dell G5 5590",
1212 		.matches = {
1213 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1214 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "G5 5590"),
1215 		},
1216 	},
1217 	{
1218 		.ident = "Dell Inspiron",
1219 		.matches = {
1220 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
1221 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
1222 		},
1223 	},
1224 	{
1225 		.ident = "Dell Latitude",
1226 		.matches = {
1227 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
1228 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
1229 		},
1230 	},
1231 	{
1232 		.ident = "Dell Inspiron 2",
1233 		.matches = {
1234 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1235 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
1236 		},
1237 	},
1238 	{
1239 		.ident = "Dell Latitude 2",
1240 		.matches = {
1241 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1242 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
1243 		},
1244 	},
1245 	{	/* UK Inspiron 6400  */
1246 		.ident = "Dell Inspiron 3",
1247 		.matches = {
1248 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1249 			DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
1250 		},
1251 	},
1252 	{
1253 		.ident = "Dell Inspiron 3",
1254 		.matches = {
1255 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1256 			DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
1257 		},
1258 	},
1259 	{
1260 		.ident = "Dell Precision",
1261 		.matches = {
1262 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1263 			DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
1264 		},
1265 	},
1266 	{
1267 		.ident = "Dell Vostro",
1268 		.matches = {
1269 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1270 			DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
1271 		},
1272 	},
1273 	{
1274 		.ident = "Dell Studio",
1275 		.matches = {
1276 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1277 			DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
1278 		},
1279 	},
1280 	{
1281 		.ident = "Dell XPS M140",
1282 		.matches = {
1283 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1284 			DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
1285 		},
1286 	},
1287 	{
1288 		.ident = "Dell XPS",
1289 		.matches = {
1290 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1291 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS"),
1292 		},
1293 	},
1294 	{ }
1295 };
1296 
1297 MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
1298 
1299 /*
1300  * Only use for machines which need some special configuration
1301  * in order to work correctly (e.g. if autoconfig fails on this machines).
1302  */
1303 struct i8k_config_data {
1304 	uint fan_mult;
1305 	uint fan_max;
1306 };
1307 
1308 enum i8k_configs {
1309 	DELL_LATITUDE_D520,
1310 	DELL_PRECISION_490,
1311 	DELL_STUDIO,
1312 	DELL_XPS,
1313 };
1314 
1315 static const struct i8k_config_data i8k_config_data[] __initconst = {
1316 	[DELL_LATITUDE_D520] = {
1317 		.fan_mult = 1,
1318 		.fan_max = I8K_FAN_TURBO,
1319 	},
1320 	[DELL_PRECISION_490] = {
1321 		.fan_mult = 1,
1322 		.fan_max = I8K_FAN_TURBO,
1323 	},
1324 	[DELL_STUDIO] = {
1325 		.fan_mult = 1,
1326 		.fan_max = I8K_FAN_HIGH,
1327 	},
1328 	[DELL_XPS] = {
1329 		.fan_mult = 1,
1330 		.fan_max = I8K_FAN_HIGH,
1331 	},
1332 };
1333 
1334 static const struct dmi_system_id i8k_config_dmi_table[] __initconst = {
1335 	{
1336 		.ident = "Dell Latitude D520",
1337 		.matches = {
1338 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1339 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
1340 		},
1341 		.driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
1342 	},
1343 	{
1344 		.ident = "Dell Precision 490",
1345 		.matches = {
1346 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1347 			DMI_MATCH(DMI_PRODUCT_NAME,
1348 				  "Precision WorkStation 490"),
1349 		},
1350 		.driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
1351 	},
1352 	{
1353 		.ident = "Dell Studio",
1354 		.matches = {
1355 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1356 			DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
1357 		},
1358 		.driver_data = (void *)&i8k_config_data[DELL_STUDIO],
1359 	},
1360 	{
1361 		.ident = "Dell XPS M140",
1362 		.matches = {
1363 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1364 			DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
1365 		},
1366 		.driver_data = (void *)&i8k_config_data[DELL_XPS],
1367 	},
1368 	{ }
1369 };
1370 
1371 /*
1372  * On some machines once I8K_SMM_GET_FAN_TYPE is issued then CPU fan speed
1373  * randomly going up and down due to bug in Dell SMM or BIOS. Here is blacklist
1374  * of affected Dell machines for which we disallow I8K_SMM_GET_FAN_TYPE call.
1375  * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=100121
1376  */
1377 static const struct dmi_system_id i8k_blacklist_fan_type_dmi_table[] __initconst = {
1378 	{
1379 		.ident = "Dell Studio XPS 8000",
1380 		.matches = {
1381 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1382 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8000"),
1383 		},
1384 	},
1385 	{
1386 		.ident = "Dell Studio XPS 8100",
1387 		.matches = {
1388 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1389 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8100"),
1390 		},
1391 	},
1392 	{
1393 		.ident = "Dell Inspiron 580",
1394 		.matches = {
1395 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1396 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 580 "),
1397 		},
1398 	},
1399 	{
1400 		.ident = "Dell Inspiron 3505",
1401 		.matches = {
1402 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1403 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 3505"),
1404 		},
1405 	},
1406 	{ }
1407 };
1408 
1409 /*
1410  * On some machines all fan related SMM functions implemented by Dell BIOS
1411  * firmware freeze kernel for about 500ms. Until Dell fixes these problems fan
1412  * support for affected blacklisted Dell machines stay disabled.
1413  * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=195751
1414  */
1415 static const struct dmi_system_id i8k_blacklist_fan_support_dmi_table[] __initconst = {
1416 	{
1417 		.ident = "Dell Inspiron 7720",
1418 		.matches = {
1419 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1420 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 7720"),
1421 		},
1422 	},
1423 	{
1424 		.ident = "Dell Vostro 3360",
1425 		.matches = {
1426 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1427 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Vostro 3360"),
1428 		},
1429 	},
1430 	{
1431 		.ident = "Dell XPS13 9333",
1432 		.matches = {
1433 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1434 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS13 9333"),
1435 		},
1436 	},
1437 	{
1438 		.ident = "Dell XPS 15 L502X",
1439 		.matches = {
1440 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1441 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L502X"),
1442 		},
1443 	},
1444 	{ }
1445 };
1446 
1447 struct i8k_fan_control_data {
1448 	unsigned int manual_fan;
1449 	unsigned int auto_fan;
1450 };
1451 
1452 enum i8k_fan_controls {
1453 	I8K_FAN_30A3_31A3,
1454 	I8K_FAN_34A3_35A3,
1455 };
1456 
1457 static const struct i8k_fan_control_data i8k_fan_control_data[] __initconst = {
1458 	[I8K_FAN_30A3_31A3] = {
1459 		.manual_fan = 0x30a3,
1460 		.auto_fan = 0x31a3,
1461 	},
1462 	[I8K_FAN_34A3_35A3] = {
1463 		.manual_fan = 0x34a3,
1464 		.auto_fan = 0x35a3,
1465 	},
1466 };
1467 
1468 static const struct dmi_system_id i8k_whitelist_fan_control[] __initconst = {
1469 	{
1470 		.ident = "Dell Latitude 5480",
1471 		.matches = {
1472 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1473 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude 5480"),
1474 		},
1475 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1476 	},
1477 	{
1478 		.ident = "Dell Latitude E6440",
1479 		.matches = {
1480 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1481 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E6440"),
1482 		},
1483 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1484 	},
1485 	{
1486 		.ident = "Dell Latitude E7440",
1487 		.matches = {
1488 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1489 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E7440"),
1490 		},
1491 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1492 	},
1493 	{
1494 		.ident = "Dell Precision 5530",
1495 		.matches = {
1496 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1497 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 5530"),
1498 		},
1499 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1500 	},
1501 	{
1502 		.ident = "Dell Precision 7510",
1503 		.matches = {
1504 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1505 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
1506 		},
1507 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1508 	},
1509 	{
1510 		.ident = "Dell XPS 13 7390",
1511 		.matches = {
1512 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1513 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS 13 7390"),
1514 		},
1515 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1516 	},
1517 	{
1518 		.ident = "Dell Optiplex 7000",
1519 		.matches = {
1520 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1521 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7000"),
1522 		},
1523 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1524 	},
1525 	{
1526 		.ident = "Dell XPS 9315",
1527 		.matches = {
1528 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1529 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS 9315"),
1530 		},
1531 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_30A3_31A3],
1532 	},
1533 	{ }
1534 };
1535 
1536 /*
1537  * Legacy SMM backend driver.
1538  */
1539 static int __init dell_smm_probe(struct platform_device *pdev)
1540 {
1541 	int ret;
1542 
1543 	ret = dell_smm_init_data(&pdev->dev, &i8k_smm_ops);
1544 	if (ret < 0)
1545 		return ret;
1546 
1547 	ret = dell_smm_init_hwmon(&pdev->dev);
1548 	if (ret)
1549 		return ret;
1550 
1551 	i8k_init_procfs(&pdev->dev);
1552 
1553 	return 0;
1554 }
1555 
1556 static struct platform_driver dell_smm_driver = {
1557 	.driver		= {
1558 		.name	= KBUILD_MODNAME,
1559 	},
1560 };
1561 
1562 static struct platform_device *dell_smm_device;
1563 
1564 /*
1565  * WMI SMM backend driver.
1566  */
1567 static int dell_smm_wmi_probe(struct wmi_device *wdev, const void *context)
1568 {
1569 	struct dell_smm_ops *ops;
1570 	int ret;
1571 
1572 	ops = devm_kzalloc(&wdev->dev, sizeof(*ops), GFP_KERNEL);
1573 	if (!ops)
1574 		return -ENOMEM;
1575 
1576 	ops->smm_call = wmi_smm_call;
1577 	ops->smm_dev = &wdev->dev;
1578 
1579 	if (dell_smm_get_signature(ops, I8K_SMM_GET_DELL_SIG1) &&
1580 	    dell_smm_get_signature(ops, I8K_SMM_GET_DELL_SIG2))
1581 		return -ENODEV;
1582 
1583 	ret = dell_smm_init_data(&wdev->dev, ops);
1584 	if (ret < 0)
1585 		return ret;
1586 
1587 	return dell_smm_init_hwmon(&wdev->dev);
1588 }
1589 
1590 static const struct wmi_device_id dell_smm_wmi_id_table[] = {
1591 	{ DELL_SMM_WMI_GUID, NULL },
1592 	{ }
1593 };
1594 MODULE_DEVICE_TABLE(wmi, dell_smm_wmi_id_table);
1595 
1596 static struct wmi_driver dell_smm_wmi_driver = {
1597 	.driver = {
1598 		.name = KBUILD_MODNAME,
1599 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1600 	},
1601 	.id_table = dell_smm_wmi_id_table,
1602 	.probe = dell_smm_wmi_probe,
1603 	.no_singleton = true,
1604 };
1605 
1606 /*
1607  * Probe for the presence of a supported laptop.
1608  */
1609 static void __init dell_smm_init_dmi(void)
1610 {
1611 	struct i8k_fan_control_data *control;
1612 	struct i8k_config_data *config;
1613 	const struct dmi_system_id *id;
1614 
1615 	if (dmi_check_system(i8k_blacklist_fan_support_dmi_table)) {
1616 		if (!force) {
1617 			pr_notice("Disabling fan support due to BIOS bugs\n");
1618 			disallow_fan_support = true;
1619 		} else {
1620 			pr_warn("Enabling fan support despite BIOS bugs\n");
1621 		}
1622 	}
1623 
1624 	if (dmi_check_system(i8k_blacklist_fan_type_dmi_table)) {
1625 		if (!force) {
1626 			pr_notice("Disabling fan type call due to BIOS bugs\n");
1627 			disallow_fan_type_call = true;
1628 		} else {
1629 			pr_warn("Enabling fan type call despite BIOS bugs\n");
1630 		}
1631 	}
1632 
1633 	/*
1634 	 * Set fan multiplier and maximal fan speed from DMI config.
1635 	 * Values specified in module parameters override values from DMI.
1636 	 */
1637 	id = dmi_first_match(i8k_config_dmi_table);
1638 	if (id && id->driver_data) {
1639 		config = id->driver_data;
1640 		if (!fan_mult && config->fan_mult)
1641 			fan_mult = config->fan_mult;
1642 
1643 		if (!fan_max && config->fan_max)
1644 			fan_max = config->fan_max;
1645 	}
1646 
1647 	id = dmi_first_match(i8k_whitelist_fan_control);
1648 	if (id && id->driver_data) {
1649 		control = id->driver_data;
1650 		manual_fan = control->manual_fan;
1651 		auto_fan = control->auto_fan;
1652 
1653 		pr_info("Enabling support for setting automatic/manual fan control\n");
1654 	}
1655 }
1656 
1657 static int __init dell_smm_legacy_check(void)
1658 {
1659 	if (!dmi_check_system(i8k_dmi_table)) {
1660 		if (!ignore_dmi && !force)
1661 			return -ENODEV;
1662 
1663 		pr_info("Probing for legacy SMM handler on unsupported machine\n");
1664 		pr_info("vendor=%s, model=%s, version=%s\n",
1665 			i8k_get_dmi_data(DMI_SYS_VENDOR),
1666 			i8k_get_dmi_data(DMI_PRODUCT_NAME),
1667 			i8k_get_dmi_data(DMI_BIOS_VERSION));
1668 	}
1669 
1670 	if (dell_smm_get_signature(&i8k_smm_ops, I8K_SMM_GET_DELL_SIG1) &&
1671 	    dell_smm_get_signature(&i8k_smm_ops, I8K_SMM_GET_DELL_SIG2)) {
1672 		if (!force)
1673 			return -ENODEV;
1674 
1675 		pr_warn("Forcing legacy SMM calls on a possibly incompatible machine\n");
1676 	}
1677 
1678 	return 0;
1679 }
1680 
1681 static int __init i8k_init(void)
1682 {
1683 	int ret;
1684 
1685 	dell_smm_init_dmi();
1686 
1687 	ret = dell_smm_legacy_check();
1688 	if (ret < 0) {
1689 		/*
1690 		 * On modern machines, SMM communication happens over WMI, meaning
1691 		 * the SMM handler might not react to legacy SMM calls.
1692 		 */
1693 		return wmi_driver_register(&dell_smm_wmi_driver);
1694 	}
1695 
1696 	dell_smm_device = platform_create_bundle(&dell_smm_driver, dell_smm_probe, NULL, 0, NULL,
1697 						 0);
1698 
1699 	return PTR_ERR_OR_ZERO(dell_smm_device);
1700 }
1701 
1702 static void __exit i8k_exit(void)
1703 {
1704 	if (dell_smm_device) {
1705 		platform_device_unregister(dell_smm_device);
1706 		platform_driver_unregister(&dell_smm_driver);
1707 	} else {
1708 		wmi_driver_unregister(&dell_smm_wmi_driver);
1709 	}
1710 }
1711 
1712 module_init(i8k_init);
1713 module_exit(i8k_exit);
1714