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/kconfig.h>
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/mutex.h>
28 #include <linux/platform_device.h>
29 #include <linux/proc_fs.h>
30 #include <linux/seq_file.h>
31 #include <linux/slab.h>
32 #include <linux/smp.h>
33 #include <linux/string.h>
34 #include <linux/thermal.h>
35 #include <linux/types.h>
36 #include <linux/uaccess.h>
37 
38 #include <linux/i8k.h>
39 
40 #define I8K_SMM_FN_STATUS	0x0025
41 #define I8K_SMM_POWER_STATUS	0x0069
42 #define I8K_SMM_SET_FAN		0x01a3
43 #define I8K_SMM_GET_FAN		0x00a3
44 #define I8K_SMM_GET_SPEED	0x02a3
45 #define I8K_SMM_GET_FAN_TYPE	0x03a3
46 #define I8K_SMM_GET_NOM_SPEED	0x04a3
47 #define I8K_SMM_GET_TEMP	0x10a3
48 #define I8K_SMM_GET_TEMP_TYPE	0x11a3
49 #define I8K_SMM_GET_DELL_SIG1	0xfea3
50 #define I8K_SMM_GET_DELL_SIG2	0xffa3
51 
52 /* in usecs */
53 #define DELL_SMM_MAX_DURATION  250000
54 
55 #define I8K_FAN_MULT		30
56 #define I8K_FAN_RPM_THRESHOLD	1000
57 #define I8K_MAX_TEMP		127
58 
59 #define I8K_FN_NONE		0x00
60 #define I8K_FN_UP		0x01
61 #define I8K_FN_DOWN		0x02
62 #define I8K_FN_MUTE		0x04
63 #define I8K_FN_MASK		0x07
64 #define I8K_FN_SHIFT		8
65 
66 #define I8K_POWER_AC		0x05
67 #define I8K_POWER_BATTERY	0x01
68 
69 #define DELL_SMM_NO_TEMP	10
70 #define DELL_SMM_NO_FANS	3
71 
72 struct dell_smm_data {
73 	struct mutex i8k_mutex; /* lock for sensors writes */
74 	char bios_version[4];
75 	char bios_machineid[16];
76 	uint i8k_fan_mult;
77 	uint i8k_pwm_mult;
78 	uint i8k_fan_max;
79 	bool disallow_fan_type_call;
80 	bool disallow_fan_support;
81 	unsigned int manual_fan;
82 	unsigned int auto_fan;
83 	int temp_type[DELL_SMM_NO_TEMP];
84 	bool fan[DELL_SMM_NO_FANS];
85 	int fan_type[DELL_SMM_NO_FANS];
86 	int *fan_nominal_speed[DELL_SMM_NO_FANS];
87 };
88 
89 struct dell_smm_cooling_data {
90 	u8 fan_num;
91 	struct dell_smm_data *data;
92 };
93 
94 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
95 MODULE_AUTHOR("Pali Rohár <pali@kernel.org>");
96 MODULE_DESCRIPTION("Dell laptop SMM BIOS hwmon driver");
97 MODULE_LICENSE("GPL");
98 MODULE_ALIAS("i8k");
99 
100 static bool force;
101 module_param_unsafe(force, bool, 0);
102 MODULE_PARM_DESC(force, "Force loading without checking for supported models and features");
103 
104 static bool ignore_dmi;
105 module_param(ignore_dmi, bool, 0);
106 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
107 
108 #if IS_ENABLED(CONFIG_I8K)
109 static bool restricted = true;
110 module_param(restricted, bool, 0);
111 MODULE_PARM_DESC(restricted, "Restrict fan control and serial number to CAP_SYS_ADMIN (default: 1)");
112 
113 static bool power_status;
114 module_param(power_status, bool, 0600);
115 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k (default: 0)");
116 #endif
117 
118 static uint fan_mult;
119 module_param(fan_mult, uint, 0);
120 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with (default: autodetect)");
121 
122 static uint fan_max;
123 module_param(fan_max, uint, 0);
124 MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autodetect)");
125 
126 struct smm_regs {
127 	unsigned int eax;
128 	unsigned int ebx;
129 	unsigned int ecx;
130 	unsigned int edx;
131 	unsigned int esi;
132 	unsigned int edi;
133 };
134 
135 static const char * const temp_labels[] = {
136 	"CPU",
137 	"GPU",
138 	"SODIMM",
139 	"Other",
140 	"Ambient",
141 	"Other",
142 };
143 
144 static const char * const fan_labels[] = {
145 	"Processor Fan",
146 	"Motherboard Fan",
147 	"Video Fan",
148 	"Power Supply Fan",
149 	"Chipset Fan",
150 	"Other Fan",
151 };
152 
153 static const char * const docking_labels[] = {
154 	"Docking Processor Fan",
155 	"Docking Motherboard Fan",
156 	"Docking Video Fan",
157 	"Docking Power Supply Fan",
158 	"Docking Chipset Fan",
159 	"Docking Other Fan",
160 };
161 
162 static inline const char __init *i8k_get_dmi_data(int field)
163 {
164 	const char *dmi_data = dmi_get_system_info(field);
165 
166 	return dmi_data && *dmi_data ? dmi_data : "?";
167 }
168 
169 /*
170  * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
171  */
172 static int i8k_smm_func(void *par)
173 {
174 	ktime_t calltime = ktime_get();
175 	struct smm_regs *regs = par;
176 	int eax = regs->eax;
177 	int ebx = regs->ebx;
178 	unsigned char carry;
179 	long long duration;
180 
181 	/* SMM requires CPU 0 */
182 	if (smp_processor_id() != 0)
183 		return -EBUSY;
184 
185 	asm volatile("out %%al,$0xb2\n\t"
186 		     "out %%al,$0x84\n\t"
187 		     "setc %0\n"
188 		     : "=mr" (carry),
189 		       "+a" (regs->eax),
190 		       "+b" (regs->ebx),
191 		       "+c" (regs->ecx),
192 		       "+d" (regs->edx),
193 		       "+S" (regs->esi),
194 		       "+D" (regs->edi));
195 
196 	duration = ktime_us_delta(ktime_get(), calltime);
197 	pr_debug("smm(0x%.4x 0x%.4x) = 0x%.4x carry: %d (took %7lld usecs)\n",
198 		 eax, ebx, regs->eax & 0xffff, carry, duration);
199 
200 	if (duration > DELL_SMM_MAX_DURATION)
201 		pr_warn_once("SMM call took %lld usecs!\n", duration);
202 
203 	if (carry || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
204 		return -EINVAL;
205 
206 	return 0;
207 }
208 
209 /*
210  * Call the System Management Mode BIOS.
211  */
212 static int i8k_smm(struct smm_regs *regs)
213 {
214 	int ret;
215 
216 	cpus_read_lock();
217 	ret = smp_call_on_cpu(0, i8k_smm_func, regs, true);
218 	cpus_read_unlock();
219 
220 	return ret;
221 }
222 
223 /*
224  * Read the fan status.
225  */
226 static int i8k_get_fan_status(const struct dell_smm_data *data, u8 fan)
227 {
228 	struct smm_regs regs = {
229 		.eax = I8K_SMM_GET_FAN,
230 		.ebx = fan,
231 	};
232 
233 	if (data->disallow_fan_support)
234 		return -EINVAL;
235 
236 	return i8k_smm(&regs) ? : regs.eax & 0xff;
237 }
238 
239 /*
240  * Read the fan speed in RPM.
241  */
242 static int i8k_get_fan_speed(const struct dell_smm_data *data, u8 fan)
243 {
244 	struct smm_regs regs = {
245 		.eax = I8K_SMM_GET_SPEED,
246 		.ebx = fan,
247 	};
248 
249 	if (data->disallow_fan_support)
250 		return -EINVAL;
251 
252 	return i8k_smm(&regs) ? : (regs.eax & 0xffff) * data->i8k_fan_mult;
253 }
254 
255 /*
256  * Read the fan type.
257  */
258 static int _i8k_get_fan_type(const struct dell_smm_data *data, u8 fan)
259 {
260 	struct smm_regs regs = {
261 		.eax = I8K_SMM_GET_FAN_TYPE,
262 		.ebx = fan,
263 	};
264 
265 	if (data->disallow_fan_support || data->disallow_fan_type_call)
266 		return -EINVAL;
267 
268 	return i8k_smm(&regs) ? : regs.eax & 0xff;
269 }
270 
271 static int i8k_get_fan_type(struct dell_smm_data *data, u8 fan)
272 {
273 	/* I8K_SMM_GET_FAN_TYPE SMM call is expensive, so cache values */
274 	if (data->fan_type[fan] == INT_MIN)
275 		data->fan_type[fan] = _i8k_get_fan_type(data, fan);
276 
277 	return data->fan_type[fan];
278 }
279 
280 /*
281  * Read the fan nominal rpm for specific fan speed.
282  */
283 static int __init i8k_get_fan_nominal_speed(const struct dell_smm_data *data, u8 fan, int speed)
284 {
285 	struct smm_regs regs = {
286 		.eax = I8K_SMM_GET_NOM_SPEED,
287 		.ebx = fan | (speed << 8),
288 	};
289 
290 	if (data->disallow_fan_support)
291 		return -EINVAL;
292 
293 	return i8k_smm(&regs) ? : (regs.eax & 0xffff);
294 }
295 
296 /*
297  * Enable or disable automatic BIOS fan control support
298  */
299 static int i8k_enable_fan_auto_mode(const struct dell_smm_data *data, bool enable)
300 {
301 	struct smm_regs regs = { };
302 
303 	if (data->disallow_fan_support)
304 		return -EINVAL;
305 
306 	regs.eax = enable ? data->auto_fan : data->manual_fan;
307 	return i8k_smm(&regs);
308 }
309 
310 /*
311  * Set the fan speed (off, low, high, ...).
312  */
313 static int i8k_set_fan(const struct dell_smm_data *data, u8 fan, int speed)
314 {
315 	struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
316 
317 	if (data->disallow_fan_support)
318 		return -EINVAL;
319 
320 	speed = (speed < 0) ? 0 : ((speed > data->i8k_fan_max) ? data->i8k_fan_max : speed);
321 	regs.ebx = fan | (speed << 8);
322 
323 	return i8k_smm(&regs);
324 }
325 
326 static int __init i8k_get_temp_type(u8 sensor)
327 {
328 	struct smm_regs regs = {
329 		.eax = I8K_SMM_GET_TEMP_TYPE,
330 		.ebx = sensor,
331 	};
332 
333 	return i8k_smm(&regs) ? : regs.eax & 0xff;
334 }
335 
336 /*
337  * Read the cpu temperature.
338  */
339 static int _i8k_get_temp(u8 sensor)
340 {
341 	struct smm_regs regs = {
342 		.eax = I8K_SMM_GET_TEMP,
343 		.ebx = sensor,
344 	};
345 
346 	return i8k_smm(&regs) ? : regs.eax & 0xff;
347 }
348 
349 static int i8k_get_temp(u8 sensor)
350 {
351 	int temp = _i8k_get_temp(sensor);
352 
353 	/*
354 	 * Sometimes the temperature sensor returns 0x99, which is out of range.
355 	 * In this case we retry (once) before returning an error.
356 	 # 1003655137 00000058 00005a4b
357 	 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
358 	 # 1003655139 00000054 00005c52
359 	 */
360 	if (temp == 0x99) {
361 		msleep(100);
362 		temp = _i8k_get_temp(sensor);
363 	}
364 	/*
365 	 * Return -ENODATA for all invalid temperatures.
366 	 *
367 	 * Known instances are the 0x99 value as seen above as well as
368 	 * 0xc1 (193), which may be returned when trying to read the GPU
369 	 * temperature if the system supports a GPU and it is currently
370 	 * turned off.
371 	 */
372 	if (temp > I8K_MAX_TEMP)
373 		return -ENODATA;
374 
375 	return temp;
376 }
377 
378 static int __init i8k_get_dell_signature(int req_fn)
379 {
380 	struct smm_regs regs = { .eax = req_fn, };
381 	int rc;
382 
383 	rc = i8k_smm(&regs);
384 	if (rc < 0)
385 		return rc;
386 
387 	return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
388 }
389 
390 #if IS_ENABLED(CONFIG_I8K)
391 
392 /*
393  * Read the Fn key status.
394  */
395 static int i8k_get_fn_status(void)
396 {
397 	struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
398 	int rc;
399 
400 	rc = i8k_smm(&regs);
401 	if (rc < 0)
402 		return rc;
403 
404 	switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
405 	case I8K_FN_UP:
406 		return I8K_VOL_UP;
407 	case I8K_FN_DOWN:
408 		return I8K_VOL_DOWN;
409 	case I8K_FN_MUTE:
410 		return I8K_VOL_MUTE;
411 	default:
412 		return 0;
413 	}
414 }
415 
416 /*
417  * Read the power status.
418  */
419 static int i8k_get_power_status(void)
420 {
421 	struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
422 	int rc;
423 
424 	rc = i8k_smm(&regs);
425 	if (rc < 0)
426 		return rc;
427 
428 	return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
429 }
430 
431 /*
432  * Procfs interface
433  */
434 
435 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
436 {
437 	struct dell_smm_data *data = pde_data(file_inode(fp));
438 	int __user *argp = (int __user *)arg;
439 	int speed, err;
440 	int val = 0;
441 
442 	if (!argp)
443 		return -EINVAL;
444 
445 	switch (cmd) {
446 	case I8K_BIOS_VERSION:
447 		if (!isdigit(data->bios_version[0]) || !isdigit(data->bios_version[1]) ||
448 		    !isdigit(data->bios_version[2]))
449 			return -EINVAL;
450 
451 		val = (data->bios_version[0] << 16) |
452 				(data->bios_version[1] << 8) | data->bios_version[2];
453 
454 		if (copy_to_user(argp, &val, sizeof(val)))
455 			return -EFAULT;
456 
457 		return 0;
458 	case I8K_MACHINE_ID:
459 		if (restricted && !capable(CAP_SYS_ADMIN))
460 			return -EPERM;
461 
462 		if (copy_to_user(argp, data->bios_machineid, sizeof(data->bios_machineid)))
463 			return -EFAULT;
464 
465 		return 0;
466 	case I8K_FN_STATUS:
467 		val = i8k_get_fn_status();
468 		break;
469 
470 	case I8K_POWER_STATUS:
471 		val = i8k_get_power_status();
472 		break;
473 
474 	case I8K_GET_TEMP:
475 		val = i8k_get_temp(0);
476 		break;
477 
478 	case I8K_GET_SPEED:
479 		if (copy_from_user(&val, argp, sizeof(int)))
480 			return -EFAULT;
481 
482 		if (val > U8_MAX || val < 0)
483 			return -EINVAL;
484 
485 		val = i8k_get_fan_speed(data, val);
486 		break;
487 
488 	case I8K_GET_FAN:
489 		if (copy_from_user(&val, argp, sizeof(int)))
490 			return -EFAULT;
491 
492 		if (val > U8_MAX || val < 0)
493 			return -EINVAL;
494 
495 		val = i8k_get_fan_status(data, val);
496 		break;
497 
498 	case I8K_SET_FAN:
499 		if (restricted && !capable(CAP_SYS_ADMIN))
500 			return -EPERM;
501 
502 		if (copy_from_user(&val, argp, sizeof(int)))
503 			return -EFAULT;
504 
505 		if (val > U8_MAX || val < 0)
506 			return -EINVAL;
507 
508 		if (copy_from_user(&speed, argp + 1, sizeof(int)))
509 			return -EFAULT;
510 
511 		mutex_lock(&data->i8k_mutex);
512 		err = i8k_set_fan(data, val, speed);
513 		if (err < 0)
514 			val = err;
515 		else
516 			val = i8k_get_fan_status(data, val);
517 		mutex_unlock(&data->i8k_mutex);
518 		break;
519 
520 	default:
521 		return -ENOIOCTLCMD;
522 	}
523 
524 	if (val < 0)
525 		return val;
526 
527 	if (copy_to_user(argp, &val, sizeof(int)))
528 		return -EFAULT;
529 
530 	return 0;
531 }
532 
533 /*
534  * Print the information for /proc/i8k.
535  */
536 static int i8k_proc_show(struct seq_file *seq, void *offset)
537 {
538 	struct dell_smm_data *data = seq->private;
539 	int fn_key, cpu_temp, ac_power;
540 	int left_fan, right_fan, left_speed, right_speed;
541 
542 	cpu_temp	= i8k_get_temp(0);				/* 11100 µs */
543 	left_fan	= i8k_get_fan_status(data, I8K_FAN_LEFT);	/*   580 µs */
544 	right_fan	= i8k_get_fan_status(data, I8K_FAN_RIGHT);	/*   580 µs */
545 	left_speed	= i8k_get_fan_speed(data, I8K_FAN_LEFT);	/*   580 µs */
546 	right_speed	= i8k_get_fan_speed(data, I8K_FAN_RIGHT);	/*   580 µs */
547 	fn_key		= i8k_get_fn_status();				/*   750 µs */
548 	if (power_status)
549 		ac_power = i8k_get_power_status();			/* 14700 µs */
550 	else
551 		ac_power = -1;
552 
553 	/*
554 	 * Info:
555 	 *
556 	 * 1)  Format version (this will change if format changes)
557 	 * 2)  BIOS version
558 	 * 3)  BIOS machine ID
559 	 * 4)  Cpu temperature
560 	 * 5)  Left fan status
561 	 * 6)  Right fan status
562 	 * 7)  Left fan speed
563 	 * 8)  Right fan speed
564 	 * 9)  AC power
565 	 * 10) Fn Key status
566 	 */
567 	seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
568 		   I8K_PROC_FMT,
569 		   data->bios_version,
570 		   (restricted && !capable(CAP_SYS_ADMIN)) ? "-1" : data->bios_machineid,
571 		   cpu_temp,
572 		   left_fan, right_fan, left_speed, right_speed,
573 		   ac_power, fn_key);
574 
575 	return 0;
576 }
577 
578 static int i8k_open_fs(struct inode *inode, struct file *file)
579 {
580 	return single_open(file, i8k_proc_show, pde_data(inode));
581 }
582 
583 static const struct proc_ops i8k_proc_ops = {
584 	.proc_open	= i8k_open_fs,
585 	.proc_read	= seq_read,
586 	.proc_lseek	= seq_lseek,
587 	.proc_release	= single_release,
588 	.proc_ioctl	= i8k_ioctl,
589 };
590 
591 static void i8k_exit_procfs(void *param)
592 {
593 	remove_proc_entry("i8k", NULL);
594 }
595 
596 static void __init i8k_init_procfs(struct device *dev)
597 {
598 	struct dell_smm_data *data = dev_get_drvdata(dev);
599 
600 	/* Only register exit function if creation was successful */
601 	if (proc_create_data("i8k", 0, NULL, &i8k_proc_ops, data))
602 		devm_add_action_or_reset(dev, i8k_exit_procfs, NULL);
603 }
604 
605 #else
606 
607 static void __init i8k_init_procfs(struct device *dev)
608 {
609 }
610 
611 #endif
612 
613 static int dell_smm_get_max_state(struct thermal_cooling_device *dev, unsigned long *state)
614 {
615 	struct dell_smm_cooling_data *cdata = dev->devdata;
616 
617 	*state = cdata->data->i8k_fan_max;
618 
619 	return 0;
620 }
621 
622 static int dell_smm_get_cur_state(struct thermal_cooling_device *dev, unsigned long *state)
623 {
624 	struct dell_smm_cooling_data *cdata = dev->devdata;
625 	int ret;
626 
627 	ret = i8k_get_fan_status(cdata->data, cdata->fan_num);
628 	if (ret < 0)
629 		return ret;
630 
631 	*state = ret;
632 
633 	return 0;
634 }
635 
636 static int dell_smm_set_cur_state(struct thermal_cooling_device *dev, unsigned long state)
637 {
638 	struct dell_smm_cooling_data *cdata = dev->devdata;
639 	struct dell_smm_data *data = cdata->data;
640 	int ret;
641 
642 	if (state > data->i8k_fan_max)
643 		return -EINVAL;
644 
645 	mutex_lock(&data->i8k_mutex);
646 	ret = i8k_set_fan(data, cdata->fan_num, (int)state);
647 	mutex_unlock(&data->i8k_mutex);
648 
649 	return ret;
650 }
651 
652 static const struct thermal_cooling_device_ops dell_smm_cooling_ops = {
653 	.get_max_state = dell_smm_get_max_state,
654 	.get_cur_state = dell_smm_get_cur_state,
655 	.set_cur_state = dell_smm_set_cur_state,
656 };
657 
658 static umode_t dell_smm_is_visible(const void *drvdata, enum hwmon_sensor_types type, u32 attr,
659 				   int channel)
660 {
661 	const struct dell_smm_data *data = drvdata;
662 
663 	switch (type) {
664 	case hwmon_temp:
665 		switch (attr) {
666 		case hwmon_temp_input:
667 			/* _i8k_get_temp() is fine since we do not care about the actual value */
668 			if (data->temp_type[channel] >= 0 || _i8k_get_temp(channel) >= 0)
669 				return 0444;
670 
671 			break;
672 		case hwmon_temp_label:
673 			if (data->temp_type[channel] >= 0)
674 				return 0444;
675 
676 			break;
677 		default:
678 			break;
679 		}
680 		break;
681 	case hwmon_fan:
682 		if (data->disallow_fan_support)
683 			break;
684 
685 		switch (attr) {
686 		case hwmon_fan_input:
687 			if (data->fan[channel])
688 				return 0444;
689 
690 			break;
691 		case hwmon_fan_label:
692 			if (data->fan[channel] && !data->disallow_fan_type_call)
693 				return 0444;
694 
695 			break;
696 		case hwmon_fan_min:
697 		case hwmon_fan_max:
698 		case hwmon_fan_target:
699 			if (data->fan_nominal_speed[channel])
700 				return 0444;
701 
702 			break;
703 		default:
704 			break;
705 		}
706 		break;
707 	case hwmon_pwm:
708 		if (data->disallow_fan_support)
709 			break;
710 
711 		switch (attr) {
712 		case hwmon_pwm_input:
713 			if (data->fan[channel])
714 				return 0644;
715 
716 			break;
717 		case hwmon_pwm_enable:
718 			if (data->auto_fan)
719 				/*
720 				 * There is no command for retrieve the current status
721 				 * from BIOS, and userspace/firmware itself can change
722 				 * it.
723 				 * Thus we can only provide write-only access for now.
724 				 */
725 				return 0200;
726 
727 			break;
728 		default:
729 			break;
730 		}
731 		break;
732 	default:
733 		break;
734 	}
735 
736 	return 0;
737 }
738 
739 static int dell_smm_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
740 			 long *val)
741 {
742 	struct dell_smm_data *data = dev_get_drvdata(dev);
743 	int mult = data->i8k_fan_mult;
744 	int ret;
745 
746 	switch (type) {
747 	case hwmon_temp:
748 		switch (attr) {
749 		case hwmon_temp_input:
750 			ret = i8k_get_temp(channel);
751 			if (ret < 0)
752 				return ret;
753 
754 			*val = ret * 1000;
755 
756 			return 0;
757 		default:
758 			break;
759 		}
760 		break;
761 	case hwmon_fan:
762 		switch (attr) {
763 		case hwmon_fan_input:
764 			ret = i8k_get_fan_speed(data, channel);
765 			if (ret < 0)
766 				return ret;
767 
768 			*val = ret;
769 
770 			return 0;
771 		case hwmon_fan_min:
772 			*val = data->fan_nominal_speed[channel][0] * mult;
773 
774 			return 0;
775 		case hwmon_fan_max:
776 			*val = data->fan_nominal_speed[channel][data->i8k_fan_max] * mult;
777 
778 			return 0;
779 		case hwmon_fan_target:
780 			ret = i8k_get_fan_status(data, channel);
781 			if (ret < 0)
782 				return ret;
783 
784 			if (ret > data->i8k_fan_max)
785 				ret = data->i8k_fan_max;
786 
787 			*val = data->fan_nominal_speed[channel][ret] * mult;
788 
789 			return 0;
790 		default:
791 			break;
792 		}
793 		break;
794 	case hwmon_pwm:
795 		switch (attr) {
796 		case hwmon_pwm_input:
797 			ret = i8k_get_fan_status(data, channel);
798 			if (ret < 0)
799 				return ret;
800 
801 			*val = clamp_val(ret * data->i8k_pwm_mult, 0, 255);
802 
803 			return 0;
804 		default:
805 			break;
806 		}
807 		break;
808 	default:
809 		break;
810 	}
811 
812 	return -EOPNOTSUPP;
813 }
814 
815 static const char *dell_smm_fan_label(struct dell_smm_data *data, int channel)
816 {
817 	bool dock = false;
818 	int type = i8k_get_fan_type(data, channel);
819 
820 	if (type < 0)
821 		return ERR_PTR(type);
822 
823 	if (type & 0x10) {
824 		dock = true;
825 		type &= 0x0F;
826 	}
827 
828 	if (type >= ARRAY_SIZE(fan_labels))
829 		type = ARRAY_SIZE(fan_labels) - 1;
830 
831 	return dock ? docking_labels[type] : fan_labels[type];
832 }
833 
834 static int dell_smm_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
835 				int channel, const char **str)
836 {
837 	struct dell_smm_data *data = dev_get_drvdata(dev);
838 
839 	switch (type) {
840 	case hwmon_temp:
841 		switch (attr) {
842 		case hwmon_temp_label:
843 			*str = temp_labels[data->temp_type[channel]];
844 			return 0;
845 		default:
846 			break;
847 		}
848 		break;
849 	case hwmon_fan:
850 		switch (attr) {
851 		case hwmon_fan_label:
852 			*str = dell_smm_fan_label(data, channel);
853 			return PTR_ERR_OR_ZERO(*str);
854 		default:
855 			break;
856 		}
857 		break;
858 	default:
859 		break;
860 	}
861 
862 	return -EOPNOTSUPP;
863 }
864 
865 static int dell_smm_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
866 			  long val)
867 {
868 	struct dell_smm_data *data = dev_get_drvdata(dev);
869 	unsigned long pwm;
870 	bool enable;
871 	int err;
872 
873 	switch (type) {
874 	case hwmon_pwm:
875 		switch (attr) {
876 		case hwmon_pwm_input:
877 			pwm = clamp_val(DIV_ROUND_CLOSEST(val, data->i8k_pwm_mult), 0,
878 					data->i8k_fan_max);
879 
880 			mutex_lock(&data->i8k_mutex);
881 			err = i8k_set_fan(data, channel, pwm);
882 			mutex_unlock(&data->i8k_mutex);
883 
884 			if (err < 0)
885 				return err;
886 
887 			return 0;
888 		case hwmon_pwm_enable:
889 			if (!val)
890 				return -EINVAL;
891 
892 			if (val == 1)
893 				enable = false;
894 			else
895 				enable = true;
896 
897 			mutex_lock(&data->i8k_mutex);
898 			err = i8k_enable_fan_auto_mode(data, enable);
899 			mutex_unlock(&data->i8k_mutex);
900 
901 			if (err < 0)
902 				return err;
903 
904 			return 0;
905 		default:
906 			break;
907 		}
908 		break;
909 	default:
910 		break;
911 	}
912 
913 	return -EOPNOTSUPP;
914 }
915 
916 static const struct hwmon_ops dell_smm_ops = {
917 	.is_visible = dell_smm_is_visible,
918 	.read = dell_smm_read,
919 	.read_string = dell_smm_read_string,
920 	.write = dell_smm_write,
921 };
922 
923 static const struct hwmon_channel_info * const dell_smm_info[] = {
924 	HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
925 	HWMON_CHANNEL_INFO(temp,
926 			   HWMON_T_INPUT | HWMON_T_LABEL,
927 			   HWMON_T_INPUT | HWMON_T_LABEL,
928 			   HWMON_T_INPUT | HWMON_T_LABEL,
929 			   HWMON_T_INPUT | HWMON_T_LABEL,
930 			   HWMON_T_INPUT | HWMON_T_LABEL,
931 			   HWMON_T_INPUT | HWMON_T_LABEL,
932 			   HWMON_T_INPUT | HWMON_T_LABEL,
933 			   HWMON_T_INPUT | HWMON_T_LABEL,
934 			   HWMON_T_INPUT | HWMON_T_LABEL,
935 			   HWMON_T_INPUT | HWMON_T_LABEL
936 			   ),
937 	HWMON_CHANNEL_INFO(fan,
938 			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
939 			   HWMON_F_TARGET,
940 			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
941 			   HWMON_F_TARGET,
942 			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
943 			   HWMON_F_TARGET
944 			   ),
945 	HWMON_CHANNEL_INFO(pwm,
946 			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
947 			   HWMON_PWM_INPUT,
948 			   HWMON_PWM_INPUT
949 			   ),
950 	NULL
951 };
952 
953 static const struct hwmon_chip_info dell_smm_chip_info = {
954 	.ops = &dell_smm_ops,
955 	.info = dell_smm_info,
956 };
957 
958 static int __init dell_smm_init_cdev(struct device *dev, u8 fan_num)
959 {
960 	struct dell_smm_data *data = dev_get_drvdata(dev);
961 	struct thermal_cooling_device *cdev;
962 	struct dell_smm_cooling_data *cdata;
963 	int ret = 0;
964 	char *name;
965 
966 	name = kasprintf(GFP_KERNEL, "dell-smm-fan%u", fan_num + 1);
967 	if (!name)
968 		return -ENOMEM;
969 
970 	cdata = devm_kmalloc(dev, sizeof(*cdata), GFP_KERNEL);
971 	if (cdata) {
972 		cdata->fan_num = fan_num;
973 		cdata->data = data;
974 		cdev = devm_thermal_of_cooling_device_register(dev, NULL, name, cdata,
975 							       &dell_smm_cooling_ops);
976 		if (IS_ERR(cdev)) {
977 			devm_kfree(dev, cdata);
978 			ret = PTR_ERR(cdev);
979 		}
980 	} else {
981 		ret = -ENOMEM;
982 	}
983 
984 	kfree(name);
985 
986 	return ret;
987 }
988 
989 static int __init dell_smm_init_hwmon(struct device *dev)
990 {
991 	struct dell_smm_data *data = dev_get_drvdata(dev);
992 	struct device *dell_smm_hwmon_dev;
993 	int state, err;
994 	u8 i;
995 
996 	for (i = 0; i < DELL_SMM_NO_TEMP; i++) {
997 		data->temp_type[i] = i8k_get_temp_type(i);
998 		if (data->temp_type[i] < 0)
999 			continue;
1000 
1001 		if (data->temp_type[i] >= ARRAY_SIZE(temp_labels))
1002 			data->temp_type[i] = ARRAY_SIZE(temp_labels) - 1;
1003 	}
1004 
1005 	for (i = 0; i < DELL_SMM_NO_FANS; i++) {
1006 		data->fan_type[i] = INT_MIN;
1007 		err = i8k_get_fan_status(data, i);
1008 		if (err < 0)
1009 			err = i8k_get_fan_type(data, i);
1010 
1011 		if (err < 0)
1012 			continue;
1013 
1014 		data->fan[i] = true;
1015 
1016 		/* the cooling device is not critical, ignore failures */
1017 		if (IS_REACHABLE(CONFIG_THERMAL)) {
1018 			err = dell_smm_init_cdev(dev, i);
1019 			if (err < 0)
1020 				dev_warn(dev, "Failed to register cooling device for fan %u\n",
1021 					 i + 1);
1022 		}
1023 
1024 		data->fan_nominal_speed[i] = devm_kmalloc_array(dev, data->i8k_fan_max + 1,
1025 								sizeof(*data->fan_nominal_speed[i]),
1026 								GFP_KERNEL);
1027 		if (!data->fan_nominal_speed[i])
1028 			continue;
1029 
1030 		for (state = 0; state <= data->i8k_fan_max; state++) {
1031 			err = i8k_get_fan_nominal_speed(data, i, state);
1032 			if (err < 0) {
1033 				/* Mark nominal speed table as invalid in case of error */
1034 				devm_kfree(dev, data->fan_nominal_speed[i]);
1035 				data->fan_nominal_speed[i] = NULL;
1036 				break;
1037 			}
1038 			data->fan_nominal_speed[i][state] = err;
1039 			/*
1040 			 * Autodetect fan multiplier based on nominal rpm if multiplier
1041 			 * was not specified as module param or in DMI. If fan reports
1042 			 * rpm value too high then set multiplier to 1.
1043 			 */
1044 			if (!fan_mult && err > I8K_FAN_RPM_THRESHOLD)
1045 				data->i8k_fan_mult = 1;
1046 		}
1047 	}
1048 
1049 	dell_smm_hwmon_dev = devm_hwmon_device_register_with_info(dev, "dell_smm", data,
1050 								  &dell_smm_chip_info, NULL);
1051 
1052 	return PTR_ERR_OR_ZERO(dell_smm_hwmon_dev);
1053 }
1054 
1055 struct i8k_config_data {
1056 	uint fan_mult;
1057 	uint fan_max;
1058 };
1059 
1060 enum i8k_configs {
1061 	DELL_LATITUDE_D520,
1062 	DELL_PRECISION_490,
1063 	DELL_STUDIO,
1064 	DELL_XPS,
1065 };
1066 
1067 /*
1068  * Only use for machines which need some special configuration
1069  * in order to work correctly (e.g. if autoconfig fails on this machines).
1070  */
1071 
1072 static const struct i8k_config_data i8k_config_data[] __initconst = {
1073 	[DELL_LATITUDE_D520] = {
1074 		.fan_mult = 1,
1075 		.fan_max = I8K_FAN_TURBO,
1076 	},
1077 	[DELL_PRECISION_490] = {
1078 		.fan_mult = 1,
1079 		.fan_max = I8K_FAN_TURBO,
1080 	},
1081 	[DELL_STUDIO] = {
1082 		.fan_mult = 1,
1083 		.fan_max = I8K_FAN_HIGH,
1084 	},
1085 	[DELL_XPS] = {
1086 		.fan_mult = 1,
1087 		.fan_max = I8K_FAN_HIGH,
1088 	},
1089 };
1090 
1091 static const struct dmi_system_id i8k_dmi_table[] __initconst = {
1092 	{
1093 		.ident = "Dell G5 5590",
1094 		.matches = {
1095 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1096 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "G5 5590"),
1097 		},
1098 	},
1099 	{
1100 		.ident = "Dell Inspiron",
1101 		.matches = {
1102 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
1103 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
1104 		},
1105 	},
1106 	{
1107 		.ident = "Dell Latitude",
1108 		.matches = {
1109 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
1110 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
1111 		},
1112 	},
1113 	{
1114 		.ident = "Dell Inspiron 2",
1115 		.matches = {
1116 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1117 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
1118 		},
1119 	},
1120 	{
1121 		.ident = "Dell Latitude D520",
1122 		.matches = {
1123 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1124 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
1125 		},
1126 		.driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
1127 	},
1128 	{
1129 		.ident = "Dell Latitude 2",
1130 		.matches = {
1131 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1132 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
1133 		},
1134 	},
1135 	{	/* UK Inspiron 6400  */
1136 		.ident = "Dell Inspiron 3",
1137 		.matches = {
1138 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1139 			DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
1140 		},
1141 	},
1142 	{
1143 		.ident = "Dell Inspiron 3",
1144 		.matches = {
1145 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1146 			DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
1147 		},
1148 	},
1149 	{
1150 		.ident = "Dell Precision 490",
1151 		.matches = {
1152 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1153 			DMI_MATCH(DMI_PRODUCT_NAME,
1154 				  "Precision WorkStation 490"),
1155 		},
1156 		.driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
1157 	},
1158 	{
1159 		.ident = "Dell Precision",
1160 		.matches = {
1161 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1162 			DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
1163 		},
1164 	},
1165 	{
1166 		.ident = "Dell Vostro",
1167 		.matches = {
1168 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1169 			DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
1170 		},
1171 	},
1172 	{
1173 		.ident = "Dell Studio",
1174 		.matches = {
1175 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1176 			DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
1177 		},
1178 		.driver_data = (void *)&i8k_config_data[DELL_STUDIO],
1179 	},
1180 	{
1181 		.ident = "Dell XPS M140",
1182 		.matches = {
1183 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1184 			DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
1185 		},
1186 		.driver_data = (void *)&i8k_config_data[DELL_XPS],
1187 	},
1188 	{
1189 		.ident = "Dell XPS",
1190 		.matches = {
1191 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1192 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS"),
1193 		},
1194 	},
1195 	{ }
1196 };
1197 
1198 MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
1199 
1200 /*
1201  * On some machines once I8K_SMM_GET_FAN_TYPE is issued then CPU fan speed
1202  * randomly going up and down due to bug in Dell SMM or BIOS. Here is blacklist
1203  * of affected Dell machines for which we disallow I8K_SMM_GET_FAN_TYPE call.
1204  * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=100121
1205  */
1206 static const struct dmi_system_id i8k_blacklist_fan_type_dmi_table[] __initconst = {
1207 	{
1208 		.ident = "Dell Studio XPS 8000",
1209 		.matches = {
1210 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1211 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8000"),
1212 		},
1213 	},
1214 	{
1215 		.ident = "Dell Studio XPS 8100",
1216 		.matches = {
1217 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1218 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8100"),
1219 		},
1220 	},
1221 	{
1222 		.ident = "Dell Inspiron 580",
1223 		.matches = {
1224 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1225 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 580 "),
1226 		},
1227 	},
1228 	{
1229 		.ident = "Dell Inspiron 3505",
1230 		.matches = {
1231 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1232 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 3505"),
1233 		},
1234 	},
1235 	{ }
1236 };
1237 
1238 /*
1239  * On some machines all fan related SMM functions implemented by Dell BIOS
1240  * firmware freeze kernel for about 500ms. Until Dell fixes these problems fan
1241  * support for affected blacklisted Dell machines stay disabled.
1242  * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=195751
1243  */
1244 static const struct dmi_system_id i8k_blacklist_fan_support_dmi_table[] __initconst = {
1245 	{
1246 		.ident = "Dell Inspiron 7720",
1247 		.matches = {
1248 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1249 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 7720"),
1250 		},
1251 	},
1252 	{
1253 		.ident = "Dell Vostro 3360",
1254 		.matches = {
1255 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1256 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Vostro 3360"),
1257 		},
1258 	},
1259 	{
1260 		.ident = "Dell XPS13 9333",
1261 		.matches = {
1262 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1263 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS13 9333"),
1264 		},
1265 	},
1266 	{
1267 		.ident = "Dell XPS 15 L502X",
1268 		.matches = {
1269 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1270 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L502X"),
1271 		},
1272 	},
1273 	{ }
1274 };
1275 
1276 struct i8k_fan_control_data {
1277 	unsigned int manual_fan;
1278 	unsigned int auto_fan;
1279 };
1280 
1281 enum i8k_fan_controls {
1282 	I8K_FAN_34A3_35A3,
1283 };
1284 
1285 static const struct i8k_fan_control_data i8k_fan_control_data[] __initconst = {
1286 	[I8K_FAN_34A3_35A3] = {
1287 		.manual_fan = 0x34a3,
1288 		.auto_fan = 0x35a3,
1289 	},
1290 };
1291 
1292 static const struct dmi_system_id i8k_whitelist_fan_control[] __initconst = {
1293 	{
1294 		.ident = "Dell Latitude 5480",
1295 		.matches = {
1296 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1297 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude 5480"),
1298 		},
1299 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1300 	},
1301 	{
1302 		.ident = "Dell Latitude E6440",
1303 		.matches = {
1304 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1305 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E6440"),
1306 		},
1307 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1308 	},
1309 	{
1310 		.ident = "Dell Latitude E7440",
1311 		.matches = {
1312 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1313 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E7440"),
1314 		},
1315 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1316 	},
1317 	{
1318 		.ident = "Dell Precision 5530",
1319 		.matches = {
1320 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1321 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 5530"),
1322 		},
1323 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1324 	},
1325 	{
1326 		.ident = "Dell Precision 7510",
1327 		.matches = {
1328 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1329 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
1330 		},
1331 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1332 	},
1333 	{
1334 		.ident = "Dell XPS 13 7390",
1335 		.matches = {
1336 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1337 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS 13 7390"),
1338 		},
1339 		.driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1340 	},
1341 	{ }
1342 };
1343 
1344 static int __init dell_smm_probe(struct platform_device *pdev)
1345 {
1346 	struct dell_smm_data *data;
1347 	const struct dmi_system_id *id, *fan_control;
1348 	int ret;
1349 
1350 	data = devm_kzalloc(&pdev->dev, sizeof(struct dell_smm_data), GFP_KERNEL);
1351 	if (!data)
1352 		return -ENOMEM;
1353 
1354 	mutex_init(&data->i8k_mutex);
1355 	platform_set_drvdata(pdev, data);
1356 
1357 	if (dmi_check_system(i8k_blacklist_fan_support_dmi_table)) {
1358 		if (!force) {
1359 			dev_notice(&pdev->dev, "Disabling fan support due to BIOS bugs\n");
1360 			data->disallow_fan_support = true;
1361 		} else {
1362 			dev_warn(&pdev->dev, "Enabling fan support despite BIOS bugs\n");
1363 		}
1364 	}
1365 
1366 	if (dmi_check_system(i8k_blacklist_fan_type_dmi_table)) {
1367 		if (!force) {
1368 			dev_notice(&pdev->dev, "Disabling fan type call due to BIOS bugs\n");
1369 			data->disallow_fan_type_call = true;
1370 		} else {
1371 			dev_warn(&pdev->dev, "Enabling fan type call despite BIOS bugs\n");
1372 		}
1373 	}
1374 
1375 	strscpy(data->bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
1376 		sizeof(data->bios_version));
1377 	strscpy(data->bios_machineid, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
1378 		sizeof(data->bios_machineid));
1379 
1380 	/*
1381 	 * Set fan multiplier and maximal fan speed from dmi config
1382 	 * Values specified in module parameters override values from dmi
1383 	 */
1384 	id = dmi_first_match(i8k_dmi_table);
1385 	if (id && id->driver_data) {
1386 		const struct i8k_config_data *conf = id->driver_data;
1387 
1388 		if (!fan_mult && conf->fan_mult)
1389 			fan_mult = conf->fan_mult;
1390 
1391 		if (!fan_max && conf->fan_max)
1392 			fan_max = conf->fan_max;
1393 	}
1394 
1395 	/* All options must not be 0 */
1396 	data->i8k_fan_mult = fan_mult ? : I8K_FAN_MULT;
1397 	data->i8k_fan_max = fan_max ? : I8K_FAN_HIGH;
1398 	data->i8k_pwm_mult = DIV_ROUND_UP(255, data->i8k_fan_max);
1399 
1400 	fan_control = dmi_first_match(i8k_whitelist_fan_control);
1401 	if (fan_control && fan_control->driver_data) {
1402 		const struct i8k_fan_control_data *control = fan_control->driver_data;
1403 
1404 		data->manual_fan = control->manual_fan;
1405 		data->auto_fan = control->auto_fan;
1406 		dev_info(&pdev->dev, "enabling support for setting automatic/manual fan control\n");
1407 	}
1408 
1409 	ret = dell_smm_init_hwmon(&pdev->dev);
1410 	if (ret)
1411 		return ret;
1412 
1413 	i8k_init_procfs(&pdev->dev);
1414 
1415 	return 0;
1416 }
1417 
1418 static struct platform_driver dell_smm_driver = {
1419 	.driver		= {
1420 		.name	= KBUILD_MODNAME,
1421 	},
1422 };
1423 
1424 static struct platform_device *dell_smm_device;
1425 
1426 /*
1427  * Probe for the presence of a supported laptop.
1428  */
1429 static int __init i8k_init(void)
1430 {
1431 	/*
1432 	 * Get DMI information
1433 	 */
1434 	if (!dmi_check_system(i8k_dmi_table)) {
1435 		if (!ignore_dmi && !force)
1436 			return -ENODEV;
1437 
1438 		pr_info("not running on a supported Dell system.\n");
1439 		pr_info("vendor=%s, model=%s, version=%s\n",
1440 			i8k_get_dmi_data(DMI_SYS_VENDOR),
1441 			i8k_get_dmi_data(DMI_PRODUCT_NAME),
1442 			i8k_get_dmi_data(DMI_BIOS_VERSION));
1443 	}
1444 
1445 	/*
1446 	 * Get SMM Dell signature
1447 	 */
1448 	if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
1449 	    i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
1450 		if (!force)
1451 			return -ENODEV;
1452 
1453 		pr_err("Unable to get Dell SMM signature\n");
1454 	}
1455 
1456 	dell_smm_device = platform_create_bundle(&dell_smm_driver, dell_smm_probe, NULL, 0, NULL,
1457 						 0);
1458 
1459 	return PTR_ERR_OR_ZERO(dell_smm_device);
1460 }
1461 
1462 static void __exit i8k_exit(void)
1463 {
1464 	platform_device_unregister(dell_smm_device);
1465 	platform_driver_unregister(&dell_smm_driver);
1466 }
1467 
1468 module_init(i8k_init);
1469 module_exit(i8k_exit);
1470