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
72struct 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
89struct dell_smm_cooling_data {
90	u8 fan_num;
91	struct dell_smm_data *data;
92};
93
94MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
95MODULE_AUTHOR("Pali Rohár <pali@kernel.org>");
96MODULE_DESCRIPTION("Dell laptop SMM BIOS hwmon driver");
97MODULE_LICENSE("GPL");
98MODULE_ALIAS("i8k");
99
100static bool force;
101module_param_unsafe(force, bool, 0);
102MODULE_PARM_DESC(force, "Force loading without checking for supported models and features");
103
104static bool ignore_dmi;
105module_param(ignore_dmi, bool, 0);
106MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
107
108#if IS_ENABLED(CONFIG_I8K)
109static bool restricted = true;
110module_param(restricted, bool, 0);
111MODULE_PARM_DESC(restricted, "Restrict fan control and serial number to CAP_SYS_ADMIN (default: 1)");
112
113static bool power_status;
114module_param(power_status, bool, 0600);
115MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k (default: 0)");
116#endif
117
118static uint fan_mult;
119module_param(fan_mult, uint, 0);
120MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with (default: autodetect)");
121
122static uint fan_max;
123module_param(fan_max, uint, 0);
124MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autodetect)");
125
126struct 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
135static const char * const temp_labels[] = {
136	"CPU",
137	"GPU",
138	"SODIMM",
139	"Other",
140	"Ambient",
141	"Other",
142};
143
144static 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
153static 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
162static 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 */
172static 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 */
212static 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 */
226static 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 */
242static 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 */
258static 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
271static 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 */
283static 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 */
299static 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 */
313static 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
326static 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 */
339static 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
349static 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
378static 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 */
395static 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 */
419static 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
435static 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 */
536static 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
578static int i8k_open_fs(struct inode *inode, struct file *file)
579{
580	return single_open(file, i8k_proc_show, pde_data(inode));
581}
582
583static 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
591static void i8k_exit_procfs(void *param)
592{
593	remove_proc_entry("i8k", NULL);
594}
595
596static 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
607static void __init i8k_init_procfs(struct device *dev)
608{
609}
610
611#endif
612
613static 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
622static 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
636static 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
652static 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
658static 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
739static 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
815static 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
834static 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
865static 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
916static 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
923static 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
953static const struct hwmon_chip_info dell_smm_chip_info = {
954	.ops = &dell_smm_ops,
955	.info = dell_smm_info,
956};
957
958static 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
989static 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
1055struct i8k_config_data {
1056	uint fan_mult;
1057	uint fan_max;
1058};
1059
1060enum 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
1072static 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
1091static 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
1198MODULE_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 */
1206static 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 */
1244static 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
1276struct i8k_fan_control_data {
1277	unsigned int manual_fan;
1278	unsigned int auto_fan;
1279};
1280
1281enum i8k_fan_controls {
1282	I8K_FAN_34A3_35A3,
1283};
1284
1285static 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
1292static 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
1344static 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
1418static struct platform_driver dell_smm_driver = {
1419	.driver		= {
1420		.name	= KBUILD_MODNAME,
1421	},
1422};
1423
1424static struct platform_device *dell_smm_device;
1425
1426/*
1427 * Probe for the presence of a supported laptop.
1428 */
1429static 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
1462static void __exit i8k_exit(void)
1463{
1464	platform_device_unregister(dell_smm_device);
1465	platform_driver_unregister(&dell_smm_driver);
1466}
1467
1468module_init(i8k_init);
1469module_exit(i8k_exit);
1470