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1 /*
2  * dell-smm-hwmon.c -- Linux driver for accessing the SMM BIOS on Dell laptops.
3  *
4  * Copyright (C) 2001  Massimo Dal Zotto <dz@debian.org>
5  *
6  * Hwmon integration:
7  * Copyright (C) 2011  Jean Delvare <jdelvare@suse.de>
8  * Copyright (C) 2013, 2014  Guenter Roeck <linux@roeck-us.net>
9  * Copyright (C) 2014, 2015  Pali Rohár <pali.rohar@gmail.com>
10  *
11  * This program is free software; you can redistribute it and/or modify it
12  * under the terms of the GNU General Public License as published by the
13  * Free Software Foundation; either version 2, or (at your option) any
14  * later version.
15  *
16  * This program is distributed in the hope that it will be useful, but
17  * WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  * General Public License for more details.
20  */
21 
22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23 
24 #include <linux/delay.h>
25 #include <linux/module.h>
26 #include <linux/types.h>
27 #include <linux/init.h>
28 #include <linux/proc_fs.h>
29 #include <linux/seq_file.h>
30 #include <linux/dmi.h>
31 #include <linux/capability.h>
32 #include <linux/mutex.h>
33 #include <linux/hwmon.h>
34 #include <linux/hwmon-sysfs.h>
35 #include <linux/uaccess.h>
36 #include <linux/io.h>
37 #include <linux/sched.h>
38 
39 #include <linux/i8k.h>
40 
41 #define I8K_SMM_FN_STATUS	0x0025
42 #define I8K_SMM_POWER_STATUS	0x0069
43 #define I8K_SMM_SET_FAN		0x01a3
44 #define I8K_SMM_GET_FAN		0x00a3
45 #define I8K_SMM_GET_SPEED	0x02a3
46 #define I8K_SMM_GET_FAN_TYPE	0x03a3
47 #define I8K_SMM_GET_NOM_SPEED	0x04a3
48 #define I8K_SMM_GET_TEMP	0x10a3
49 #define I8K_SMM_GET_TEMP_TYPE	0x11a3
50 #define I8K_SMM_GET_DELL_SIG1	0xfea3
51 #define I8K_SMM_GET_DELL_SIG2	0xffa3
52 
53 #define I8K_FAN_MULT		30
54 #define I8K_FAN_MAX_RPM		30000
55 #define I8K_MAX_TEMP		127
56 
57 #define I8K_FN_NONE		0x00
58 #define I8K_FN_UP		0x01
59 #define I8K_FN_DOWN		0x02
60 #define I8K_FN_MUTE		0x04
61 #define I8K_FN_MASK		0x07
62 #define I8K_FN_SHIFT		8
63 
64 #define I8K_POWER_AC		0x05
65 #define I8K_POWER_BATTERY	0x01
66 
67 static DEFINE_MUTEX(i8k_mutex);
68 static char bios_version[4];
69 static char bios_machineid[16];
70 static struct device *i8k_hwmon_dev;
71 static u32 i8k_hwmon_flags;
72 static uint i8k_fan_mult = I8K_FAN_MULT;
73 static uint i8k_pwm_mult;
74 static uint i8k_fan_max = I8K_FAN_HIGH;
75 static bool disallow_fan_type_call;
76 
77 #define I8K_HWMON_HAVE_TEMP1	(1 << 0)
78 #define I8K_HWMON_HAVE_TEMP2	(1 << 1)
79 #define I8K_HWMON_HAVE_TEMP3	(1 << 2)
80 #define I8K_HWMON_HAVE_TEMP4	(1 << 3)
81 #define I8K_HWMON_HAVE_FAN1	(1 << 4)
82 #define I8K_HWMON_HAVE_FAN2	(1 << 5)
83 
84 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
85 MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
86 MODULE_DESCRIPTION("Dell laptop SMM BIOS hwmon driver");
87 MODULE_LICENSE("GPL");
88 MODULE_ALIAS("i8k");
89 
90 static bool force;
91 module_param(force, bool, 0);
92 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
93 
94 static bool ignore_dmi;
95 module_param(ignore_dmi, bool, 0);
96 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
97 
98 #if IS_ENABLED(CONFIG_I8K)
99 static bool restricted = true;
100 module_param(restricted, bool, 0);
101 MODULE_PARM_DESC(restricted, "Restrict fan control and serial number to CAP_SYS_ADMIN (default: 1)");
102 
103 static bool power_status;
104 module_param(power_status, bool, 0600);
105 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k (default: 0)");
106 #endif
107 
108 static uint fan_mult;
109 module_param(fan_mult, uint, 0);
110 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with (default: autodetect)");
111 
112 static uint fan_max;
113 module_param(fan_max, uint, 0);
114 MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autodetect)");
115 
116 struct smm_regs {
117 	unsigned int eax;
118 	unsigned int ebx __packed;
119 	unsigned int ecx __packed;
120 	unsigned int edx __packed;
121 	unsigned int esi __packed;
122 	unsigned int edi __packed;
123 };
124 
i8k_get_dmi_data(int field)125 static inline const char *i8k_get_dmi_data(int field)
126 {
127 	const char *dmi_data = dmi_get_system_info(field);
128 
129 	return dmi_data && *dmi_data ? dmi_data : "?";
130 }
131 
132 /*
133  * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
134  */
i8k_smm(struct smm_regs * regs)135 static int i8k_smm(struct smm_regs *regs)
136 {
137 	int rc;
138 	int eax = regs->eax;
139 	cpumask_var_t old_mask;
140 
141 	/* SMM requires CPU 0 */
142 	if (!alloc_cpumask_var(&old_mask, GFP_KERNEL))
143 		return -ENOMEM;
144 	cpumask_copy(old_mask, &current->cpus_allowed);
145 	rc = set_cpus_allowed_ptr(current, cpumask_of(0));
146 	if (rc)
147 		goto out;
148 	if (smp_processor_id() != 0) {
149 		rc = -EBUSY;
150 		goto out;
151 	}
152 
153 #if defined(CONFIG_X86_64)
154 	asm volatile("pushq %%rax\n\t"
155 		"movl 0(%%rax),%%edx\n\t"
156 		"pushq %%rdx\n\t"
157 		"movl 4(%%rax),%%ebx\n\t"
158 		"movl 8(%%rax),%%ecx\n\t"
159 		"movl 12(%%rax),%%edx\n\t"
160 		"movl 16(%%rax),%%esi\n\t"
161 		"movl 20(%%rax),%%edi\n\t"
162 		"popq %%rax\n\t"
163 		"out %%al,$0xb2\n\t"
164 		"out %%al,$0x84\n\t"
165 		"xchgq %%rax,(%%rsp)\n\t"
166 		"movl %%ebx,4(%%rax)\n\t"
167 		"movl %%ecx,8(%%rax)\n\t"
168 		"movl %%edx,12(%%rax)\n\t"
169 		"movl %%esi,16(%%rax)\n\t"
170 		"movl %%edi,20(%%rax)\n\t"
171 		"popq %%rdx\n\t"
172 		"movl %%edx,0(%%rax)\n\t"
173 		"pushfq\n\t"
174 		"popq %%rax\n\t"
175 		"andl $1,%%eax\n"
176 		: "=a"(rc)
177 		:    "a"(regs)
178 		:    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
179 #else
180 	asm volatile("pushl %%eax\n\t"
181 	    "movl 0(%%eax),%%edx\n\t"
182 	    "push %%edx\n\t"
183 	    "movl 4(%%eax),%%ebx\n\t"
184 	    "movl 8(%%eax),%%ecx\n\t"
185 	    "movl 12(%%eax),%%edx\n\t"
186 	    "movl 16(%%eax),%%esi\n\t"
187 	    "movl 20(%%eax),%%edi\n\t"
188 	    "popl %%eax\n\t"
189 	    "out %%al,$0xb2\n\t"
190 	    "out %%al,$0x84\n\t"
191 	    "xchgl %%eax,(%%esp)\n\t"
192 	    "movl %%ebx,4(%%eax)\n\t"
193 	    "movl %%ecx,8(%%eax)\n\t"
194 	    "movl %%edx,12(%%eax)\n\t"
195 	    "movl %%esi,16(%%eax)\n\t"
196 	    "movl %%edi,20(%%eax)\n\t"
197 	    "popl %%edx\n\t"
198 	    "movl %%edx,0(%%eax)\n\t"
199 	    "lahf\n\t"
200 	    "shrl $8,%%eax\n\t"
201 	    "andl $1,%%eax\n"
202 	    : "=a"(rc)
203 	    :    "a"(regs)
204 	    :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
205 #endif
206 	if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
207 		rc = -EINVAL;
208 
209 out:
210 	set_cpus_allowed_ptr(current, old_mask);
211 	free_cpumask_var(old_mask);
212 	return rc;
213 }
214 
215 /*
216  * Read the fan status.
217  */
i8k_get_fan_status(int fan)218 static int i8k_get_fan_status(int fan)
219 {
220 	struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
221 
222 	regs.ebx = fan & 0xff;
223 	return i8k_smm(&regs) ? : regs.eax & 0xff;
224 }
225 
226 /*
227  * Read the fan speed in RPM.
228  */
i8k_get_fan_speed(int fan)229 static int i8k_get_fan_speed(int fan)
230 {
231 	struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
232 
233 	regs.ebx = fan & 0xff;
234 	return i8k_smm(&regs) ? : (regs.eax & 0xffff) * i8k_fan_mult;
235 }
236 
237 /*
238  * Read the fan type.
239  */
_i8k_get_fan_type(int fan)240 static int _i8k_get_fan_type(int fan)
241 {
242 	struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_TYPE, };
243 
244 	if (disallow_fan_type_call)
245 		return -EINVAL;
246 
247 	regs.ebx = fan & 0xff;
248 	return i8k_smm(&regs) ? : regs.eax & 0xff;
249 }
250 
i8k_get_fan_type(int fan)251 static int i8k_get_fan_type(int fan)
252 {
253 	/* I8K_SMM_GET_FAN_TYPE SMM call is expensive, so cache values */
254 	static int types[2] = { INT_MIN, INT_MIN };
255 
256 	if (types[fan] == INT_MIN)
257 		types[fan] = _i8k_get_fan_type(fan);
258 
259 	return types[fan];
260 }
261 
262 /*
263  * Read the fan nominal rpm for specific fan speed.
264  */
i8k_get_fan_nominal_speed(int fan,int speed)265 static int i8k_get_fan_nominal_speed(int fan, int speed)
266 {
267 	struct smm_regs regs = { .eax = I8K_SMM_GET_NOM_SPEED, };
268 
269 	regs.ebx = (fan & 0xff) | (speed << 8);
270 	return i8k_smm(&regs) ? : (regs.eax & 0xffff) * i8k_fan_mult;
271 }
272 
273 /*
274  * Set the fan speed (off, low, high). Returns the new fan status.
275  */
i8k_set_fan(int fan,int speed)276 static int i8k_set_fan(int fan, int speed)
277 {
278 	struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
279 
280 	speed = (speed < 0) ? 0 : ((speed > i8k_fan_max) ? i8k_fan_max : speed);
281 	regs.ebx = (fan & 0xff) | (speed << 8);
282 
283 	return i8k_smm(&regs) ? : i8k_get_fan_status(fan);
284 }
285 
i8k_get_temp_type(int sensor)286 static int i8k_get_temp_type(int sensor)
287 {
288 	struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP_TYPE, };
289 
290 	regs.ebx = sensor & 0xff;
291 	return i8k_smm(&regs) ? : regs.eax & 0xff;
292 }
293 
294 /*
295  * Read the cpu temperature.
296  */
_i8k_get_temp(int sensor)297 static int _i8k_get_temp(int sensor)
298 {
299 	struct smm_regs regs = {
300 		.eax = I8K_SMM_GET_TEMP,
301 		.ebx = sensor & 0xff,
302 	};
303 
304 	return i8k_smm(&regs) ? : regs.eax & 0xff;
305 }
306 
i8k_get_temp(int sensor)307 static int i8k_get_temp(int sensor)
308 {
309 	int temp = _i8k_get_temp(sensor);
310 
311 	/*
312 	 * Sometimes the temperature sensor returns 0x99, which is out of range.
313 	 * In this case we retry (once) before returning an error.
314 	 # 1003655137 00000058 00005a4b
315 	 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
316 	 # 1003655139 00000054 00005c52
317 	 */
318 	if (temp == 0x99) {
319 		msleep(100);
320 		temp = _i8k_get_temp(sensor);
321 	}
322 	/*
323 	 * Return -ENODATA for all invalid temperatures.
324 	 *
325 	 * Known instances are the 0x99 value as seen above as well as
326 	 * 0xc1 (193), which may be returned when trying to read the GPU
327 	 * temperature if the system supports a GPU and it is currently
328 	 * turned off.
329 	 */
330 	if (temp > I8K_MAX_TEMP)
331 		return -ENODATA;
332 
333 	return temp;
334 }
335 
i8k_get_dell_signature(int req_fn)336 static int i8k_get_dell_signature(int req_fn)
337 {
338 	struct smm_regs regs = { .eax = req_fn, };
339 	int rc;
340 
341 	rc = i8k_smm(&regs);
342 	if (rc < 0)
343 		return rc;
344 
345 	return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
346 }
347 
348 #if IS_ENABLED(CONFIG_I8K)
349 
350 /*
351  * Read the Fn key status.
352  */
i8k_get_fn_status(void)353 static int i8k_get_fn_status(void)
354 {
355 	struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
356 	int rc;
357 
358 	rc = i8k_smm(&regs);
359 	if (rc < 0)
360 		return rc;
361 
362 	switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
363 	case I8K_FN_UP:
364 		return I8K_VOL_UP;
365 	case I8K_FN_DOWN:
366 		return I8K_VOL_DOWN;
367 	case I8K_FN_MUTE:
368 		return I8K_VOL_MUTE;
369 	default:
370 		return 0;
371 	}
372 }
373 
374 /*
375  * Read the power status.
376  */
i8k_get_power_status(void)377 static int i8k_get_power_status(void)
378 {
379 	struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
380 	int rc;
381 
382 	rc = i8k_smm(&regs);
383 	if (rc < 0)
384 		return rc;
385 
386 	return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
387 }
388 
389 /*
390  * Procfs interface
391  */
392 
393 static int
i8k_ioctl_unlocked(struct file * fp,unsigned int cmd,unsigned long arg)394 i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
395 {
396 	int val = 0;
397 	int speed;
398 	unsigned char buff[16];
399 	int __user *argp = (int __user *)arg;
400 
401 	if (!argp)
402 		return -EINVAL;
403 
404 	switch (cmd) {
405 	case I8K_BIOS_VERSION:
406 		val = (bios_version[0] << 16) |
407 				(bios_version[1] << 8) | bios_version[2];
408 		break;
409 
410 	case I8K_MACHINE_ID:
411 		if (restricted && !capable(CAP_SYS_ADMIN))
412 			return -EPERM;
413 
414 		memset(buff, 0, sizeof(buff));
415 		strlcpy(buff, bios_machineid, sizeof(buff));
416 		break;
417 
418 	case I8K_FN_STATUS:
419 		val = i8k_get_fn_status();
420 		break;
421 
422 	case I8K_POWER_STATUS:
423 		val = i8k_get_power_status();
424 		break;
425 
426 	case I8K_GET_TEMP:
427 		val = i8k_get_temp(0);
428 		break;
429 
430 	case I8K_GET_SPEED:
431 		if (copy_from_user(&val, argp, sizeof(int)))
432 			return -EFAULT;
433 
434 		val = i8k_get_fan_speed(val);
435 		break;
436 
437 	case I8K_GET_FAN:
438 		if (copy_from_user(&val, argp, sizeof(int)))
439 			return -EFAULT;
440 
441 		val = i8k_get_fan_status(val);
442 		break;
443 
444 	case I8K_SET_FAN:
445 		if (restricted && !capable(CAP_SYS_ADMIN))
446 			return -EPERM;
447 
448 		if (copy_from_user(&val, argp, sizeof(int)))
449 			return -EFAULT;
450 
451 		if (copy_from_user(&speed, argp + 1, sizeof(int)))
452 			return -EFAULT;
453 
454 		val = i8k_set_fan(val, speed);
455 		break;
456 
457 	default:
458 		return -EINVAL;
459 	}
460 
461 	if (val < 0)
462 		return val;
463 
464 	switch (cmd) {
465 	case I8K_BIOS_VERSION:
466 		if (copy_to_user(argp, &val, 4))
467 			return -EFAULT;
468 
469 		break;
470 	case I8K_MACHINE_ID:
471 		if (copy_to_user(argp, buff, 16))
472 			return -EFAULT;
473 
474 		break;
475 	default:
476 		if (copy_to_user(argp, &val, sizeof(int)))
477 			return -EFAULT;
478 
479 		break;
480 	}
481 
482 	return 0;
483 }
484 
i8k_ioctl(struct file * fp,unsigned int cmd,unsigned long arg)485 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
486 {
487 	long ret;
488 
489 	mutex_lock(&i8k_mutex);
490 	ret = i8k_ioctl_unlocked(fp, cmd, arg);
491 	mutex_unlock(&i8k_mutex);
492 
493 	return ret;
494 }
495 
496 /*
497  * Print the information for /proc/i8k.
498  */
i8k_proc_show(struct seq_file * seq,void * offset)499 static int i8k_proc_show(struct seq_file *seq, void *offset)
500 {
501 	int fn_key, cpu_temp, ac_power;
502 	int left_fan, right_fan, left_speed, right_speed;
503 
504 	cpu_temp	= i8k_get_temp(0);			/* 11100 µs */
505 	left_fan	= i8k_get_fan_status(I8K_FAN_LEFT);	/*   580 µs */
506 	right_fan	= i8k_get_fan_status(I8K_FAN_RIGHT);	/*   580 µs */
507 	left_speed	= i8k_get_fan_speed(I8K_FAN_LEFT);	/*   580 µs */
508 	right_speed	= i8k_get_fan_speed(I8K_FAN_RIGHT);	/*   580 µs */
509 	fn_key		= i8k_get_fn_status();			/*   750 µs */
510 	if (power_status)
511 		ac_power = i8k_get_power_status();		/* 14700 µs */
512 	else
513 		ac_power = -1;
514 
515 	/*
516 	 * Info:
517 	 *
518 	 * 1)  Format version (this will change if format changes)
519 	 * 2)  BIOS version
520 	 * 3)  BIOS machine ID
521 	 * 4)  Cpu temperature
522 	 * 5)  Left fan status
523 	 * 6)  Right fan status
524 	 * 7)  Left fan speed
525 	 * 8)  Right fan speed
526 	 * 9)  AC power
527 	 * 10) Fn Key status
528 	 */
529 	seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
530 		   I8K_PROC_FMT,
531 		   bios_version,
532 		   (restricted && !capable(CAP_SYS_ADMIN)) ? "-1" : bios_machineid,
533 		   cpu_temp,
534 		   left_fan, right_fan, left_speed, right_speed,
535 		   ac_power, fn_key);
536 
537 	return 0;
538 }
539 
i8k_open_fs(struct inode * inode,struct file * file)540 static int i8k_open_fs(struct inode *inode, struct file *file)
541 {
542 	return single_open(file, i8k_proc_show, NULL);
543 }
544 
545 static const struct file_operations i8k_fops = {
546 	.owner		= THIS_MODULE,
547 	.open		= i8k_open_fs,
548 	.read		= seq_read,
549 	.llseek		= seq_lseek,
550 	.release	= single_release,
551 	.unlocked_ioctl	= i8k_ioctl,
552 };
553 
554 static struct proc_dir_entry *entry;
555 
i8k_init_procfs(void)556 static void __init i8k_init_procfs(void)
557 {
558 	/* Register the proc entry */
559 	entry = proc_create("i8k", 0, NULL, &i8k_fops);
560 }
561 
i8k_exit_procfs(void)562 static void __exit i8k_exit_procfs(void)
563 {
564 	if (entry)
565 		remove_proc_entry("i8k", NULL);
566 }
567 
568 #else
569 
i8k_init_procfs(void)570 static inline void __init i8k_init_procfs(void)
571 {
572 }
573 
i8k_exit_procfs(void)574 static inline void __exit i8k_exit_procfs(void)
575 {
576 }
577 
578 #endif
579 
580 /*
581  * Hwmon interface
582  */
583 
i8k_hwmon_show_temp_label(struct device * dev,struct device_attribute * devattr,char * buf)584 static ssize_t i8k_hwmon_show_temp_label(struct device *dev,
585 					 struct device_attribute *devattr,
586 					 char *buf)
587 {
588 	static const char * const labels[] = {
589 		"CPU",
590 		"GPU",
591 		"SODIMM",
592 		"Other",
593 		"Ambient",
594 		"Other",
595 	};
596 	int index = to_sensor_dev_attr(devattr)->index;
597 	int type;
598 
599 	type = i8k_get_temp_type(index);
600 	if (type < 0)
601 		return type;
602 	if (type >= ARRAY_SIZE(labels))
603 		type = ARRAY_SIZE(labels) - 1;
604 	return sprintf(buf, "%s\n", labels[type]);
605 }
606 
i8k_hwmon_show_temp(struct device * dev,struct device_attribute * devattr,char * buf)607 static ssize_t i8k_hwmon_show_temp(struct device *dev,
608 				   struct device_attribute *devattr,
609 				   char *buf)
610 {
611 	int index = to_sensor_dev_attr(devattr)->index;
612 	int temp;
613 
614 	temp = i8k_get_temp(index);
615 	if (temp < 0)
616 		return temp;
617 	return sprintf(buf, "%d\n", temp * 1000);
618 }
619 
i8k_hwmon_show_fan_label(struct device * dev,struct device_attribute * devattr,char * buf)620 static ssize_t i8k_hwmon_show_fan_label(struct device *dev,
621 					struct device_attribute *devattr,
622 					char *buf)
623 {
624 	static const char * const labels[] = {
625 		"Processor Fan",
626 		"Motherboard Fan",
627 		"Video Fan",
628 		"Power Supply Fan",
629 		"Chipset Fan",
630 		"Other Fan",
631 	};
632 	int index = to_sensor_dev_attr(devattr)->index;
633 	bool dock = false;
634 	int type;
635 
636 	type = i8k_get_fan_type(index);
637 	if (type < 0)
638 		return type;
639 
640 	if (type & 0x10) {
641 		dock = true;
642 		type &= 0x0F;
643 	}
644 
645 	if (type >= ARRAY_SIZE(labels))
646 		type = (ARRAY_SIZE(labels) - 1);
647 
648 	return sprintf(buf, "%s%s\n", (dock ? "Docking " : ""), labels[type]);
649 }
650 
i8k_hwmon_show_fan(struct device * dev,struct device_attribute * devattr,char * buf)651 static ssize_t i8k_hwmon_show_fan(struct device *dev,
652 				  struct device_attribute *devattr,
653 				  char *buf)
654 {
655 	int index = to_sensor_dev_attr(devattr)->index;
656 	int fan_speed;
657 
658 	fan_speed = i8k_get_fan_speed(index);
659 	if (fan_speed < 0)
660 		return fan_speed;
661 	return sprintf(buf, "%d\n", fan_speed);
662 }
663 
i8k_hwmon_show_pwm(struct device * dev,struct device_attribute * devattr,char * buf)664 static ssize_t i8k_hwmon_show_pwm(struct device *dev,
665 				  struct device_attribute *devattr,
666 				  char *buf)
667 {
668 	int index = to_sensor_dev_attr(devattr)->index;
669 	int status;
670 
671 	status = i8k_get_fan_status(index);
672 	if (status < 0)
673 		return -EIO;
674 	return sprintf(buf, "%d\n", clamp_val(status * i8k_pwm_mult, 0, 255));
675 }
676 
i8k_hwmon_set_pwm(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)677 static ssize_t i8k_hwmon_set_pwm(struct device *dev,
678 				 struct device_attribute *attr,
679 				 const char *buf, size_t count)
680 {
681 	int index = to_sensor_dev_attr(attr)->index;
682 	unsigned long val;
683 	int err;
684 
685 	err = kstrtoul(buf, 10, &val);
686 	if (err)
687 		return err;
688 	val = clamp_val(DIV_ROUND_CLOSEST(val, i8k_pwm_mult), 0, i8k_fan_max);
689 
690 	mutex_lock(&i8k_mutex);
691 	err = i8k_set_fan(index, val);
692 	mutex_unlock(&i8k_mutex);
693 
694 	return err < 0 ? -EIO : count;
695 }
696 
697 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 0);
698 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
699 			  0);
700 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 1);
701 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
702 			  1);
703 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 2);
704 static SENSOR_DEVICE_ATTR(temp3_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
705 			  2);
706 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 3);
707 static SENSOR_DEVICE_ATTR(temp4_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
708 			  3);
709 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, i8k_hwmon_show_fan, NULL, 0);
710 static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, i8k_hwmon_show_fan_label, NULL,
711 			  0);
712 static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
713 			  i8k_hwmon_set_pwm, 0);
714 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
715 			  1);
716 static SENSOR_DEVICE_ATTR(fan2_label, S_IRUGO, i8k_hwmon_show_fan_label, NULL,
717 			  1);
718 static SENSOR_DEVICE_ATTR(pwm2, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
719 			  i8k_hwmon_set_pwm, 1);
720 
721 static struct attribute *i8k_attrs[] = {
722 	&sensor_dev_attr_temp1_input.dev_attr.attr,	/* 0 */
723 	&sensor_dev_attr_temp1_label.dev_attr.attr,	/* 1 */
724 	&sensor_dev_attr_temp2_input.dev_attr.attr,	/* 2 */
725 	&sensor_dev_attr_temp2_label.dev_attr.attr,	/* 3 */
726 	&sensor_dev_attr_temp3_input.dev_attr.attr,	/* 4 */
727 	&sensor_dev_attr_temp3_label.dev_attr.attr,	/* 5 */
728 	&sensor_dev_attr_temp4_input.dev_attr.attr,	/* 6 */
729 	&sensor_dev_attr_temp4_label.dev_attr.attr,	/* 7 */
730 	&sensor_dev_attr_fan1_input.dev_attr.attr,	/* 8 */
731 	&sensor_dev_attr_fan1_label.dev_attr.attr,	/* 9 */
732 	&sensor_dev_attr_pwm1.dev_attr.attr,		/* 10 */
733 	&sensor_dev_attr_fan2_input.dev_attr.attr,	/* 11 */
734 	&sensor_dev_attr_fan2_label.dev_attr.attr,	/* 12 */
735 	&sensor_dev_attr_pwm2.dev_attr.attr,		/* 13 */
736 	NULL
737 };
738 
i8k_is_visible(struct kobject * kobj,struct attribute * attr,int index)739 static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
740 			      int index)
741 {
742 	if (disallow_fan_type_call &&
743 	    (index == 9 || index == 12))
744 		return 0;
745 	if (index >= 0 && index <= 1 &&
746 	    !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP1))
747 		return 0;
748 	if (index >= 2 && index <= 3 &&
749 	    !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP2))
750 		return 0;
751 	if (index >= 4 && index <= 5 &&
752 	    !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP3))
753 		return 0;
754 	if (index >= 6 && index <= 7 &&
755 	    !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP4))
756 		return 0;
757 	if (index >= 8 && index <= 10 &&
758 	    !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN1))
759 		return 0;
760 	if (index >= 11 && index <= 13 &&
761 	    !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN2))
762 		return 0;
763 
764 	return attr->mode;
765 }
766 
767 static const struct attribute_group i8k_group = {
768 	.attrs = i8k_attrs,
769 	.is_visible = i8k_is_visible,
770 };
771 __ATTRIBUTE_GROUPS(i8k);
772 
i8k_init_hwmon(void)773 static int __init i8k_init_hwmon(void)
774 {
775 	int err;
776 
777 	i8k_hwmon_flags = 0;
778 
779 	/* CPU temperature attributes, if temperature type is OK */
780 	err = i8k_get_temp_type(0);
781 	if (err >= 0)
782 		i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1;
783 	/* check for additional temperature sensors */
784 	err = i8k_get_temp_type(1);
785 	if (err >= 0)
786 		i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP2;
787 	err = i8k_get_temp_type(2);
788 	if (err >= 0)
789 		i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP3;
790 	err = i8k_get_temp_type(3);
791 	if (err >= 0)
792 		i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4;
793 
794 	/* First fan attributes, if fan status or type is OK */
795 	err = i8k_get_fan_status(0);
796 	if (err < 0)
797 		err = i8k_get_fan_type(0);
798 	if (err >= 0)
799 		i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN1;
800 
801 	/* Second fan attributes, if fan status or type is OK */
802 	err = i8k_get_fan_status(1);
803 	if (err < 0)
804 		err = i8k_get_fan_type(1);
805 	if (err >= 0)
806 		i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;
807 
808 	i8k_hwmon_dev = hwmon_device_register_with_groups(NULL, "dell_smm",
809 							  NULL, i8k_groups);
810 	if (IS_ERR(i8k_hwmon_dev)) {
811 		err = PTR_ERR(i8k_hwmon_dev);
812 		i8k_hwmon_dev = NULL;
813 		pr_err("hwmon registration failed (%d)\n", err);
814 		return err;
815 	}
816 	return 0;
817 }
818 
819 struct i8k_config_data {
820 	uint fan_mult;
821 	uint fan_max;
822 };
823 
824 enum i8k_configs {
825 	DELL_LATITUDE_D520,
826 	DELL_PRECISION_490,
827 	DELL_STUDIO,
828 	DELL_XPS,
829 };
830 
831 static const struct i8k_config_data i8k_config_data[] = {
832 	[DELL_LATITUDE_D520] = {
833 		.fan_mult = 1,
834 		.fan_max = I8K_FAN_TURBO,
835 	},
836 	[DELL_PRECISION_490] = {
837 		.fan_mult = 1,
838 		.fan_max = I8K_FAN_TURBO,
839 	},
840 	[DELL_STUDIO] = {
841 		.fan_mult = 1,
842 		.fan_max = I8K_FAN_HIGH,
843 	},
844 	[DELL_XPS] = {
845 		.fan_mult = 1,
846 		.fan_max = I8K_FAN_HIGH,
847 	},
848 };
849 
850 static struct dmi_system_id i8k_dmi_table[] __initdata = {
851 	{
852 		.ident = "Dell Inspiron",
853 		.matches = {
854 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
855 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
856 		},
857 	},
858 	{
859 		.ident = "Dell Latitude",
860 		.matches = {
861 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
862 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
863 		},
864 	},
865 	{
866 		.ident = "Dell Inspiron 2",
867 		.matches = {
868 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
869 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
870 		},
871 	},
872 	{
873 		.ident = "Dell Latitude D520",
874 		.matches = {
875 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
876 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
877 		},
878 		.driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
879 	},
880 	{
881 		.ident = "Dell Latitude 2",
882 		.matches = {
883 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
884 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
885 		},
886 	},
887 	{	/* UK Inspiron 6400  */
888 		.ident = "Dell Inspiron 3",
889 		.matches = {
890 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
891 			DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
892 		},
893 	},
894 	{
895 		.ident = "Dell Inspiron 3",
896 		.matches = {
897 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
898 			DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
899 		},
900 	},
901 	{
902 		.ident = "Dell Precision 490",
903 		.matches = {
904 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
905 			DMI_MATCH(DMI_PRODUCT_NAME,
906 				  "Precision WorkStation 490"),
907 		},
908 		.driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
909 	},
910 	{
911 		.ident = "Dell Precision",
912 		.matches = {
913 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
914 			DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
915 		},
916 	},
917 	{
918 		.ident = "Dell Vostro",
919 		.matches = {
920 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
921 			DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
922 		},
923 	},
924 	{
925 		.ident = "Dell XPS421",
926 		.matches = {
927 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
928 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
929 		},
930 	},
931 	{
932 		.ident = "Dell Studio",
933 		.matches = {
934 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
935 			DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
936 		},
937 		.driver_data = (void *)&i8k_config_data[DELL_STUDIO],
938 	},
939 	{
940 		.ident = "Dell XPS 13",
941 		.matches = {
942 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
943 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS13"),
944 		},
945 		.driver_data = (void *)&i8k_config_data[DELL_XPS],
946 	},
947 	{
948 		.ident = "Dell XPS M140",
949 		.matches = {
950 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
951 			DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
952 		},
953 		.driver_data = (void *)&i8k_config_data[DELL_XPS],
954 	},
955 	{ }
956 };
957 
958 MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
959 
960 /*
961  * On some machines once I8K_SMM_GET_FAN_TYPE is issued then CPU fan speed
962  * randomly going up and down due to bug in Dell SMM or BIOS. Here is blacklist
963  * of affected Dell machines for which we disallow I8K_SMM_GET_FAN_TYPE call.
964  * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=100121
965  */
966 static struct dmi_system_id i8k_blacklist_fan_type_dmi_table[] __initdata = {
967 	{
968 		.ident = "Dell Studio XPS 8000",
969 		.matches = {
970 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
971 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8000"),
972 		},
973 	},
974 	{
975 		.ident = "Dell Studio XPS 8100",
976 		.matches = {
977 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
978 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8100"),
979 		},
980 	},
981 	{
982 		.ident = "Dell Inspiron 580",
983 		.matches = {
984 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
985 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 580 "),
986 		},
987 	},
988 	{ }
989 };
990 
991 /*
992  * Probe for the presence of a supported laptop.
993  */
i8k_probe(void)994 static int __init i8k_probe(void)
995 {
996 	const struct dmi_system_id *id;
997 	int fan, ret;
998 
999 	/*
1000 	 * Get DMI information
1001 	 */
1002 	if (!dmi_check_system(i8k_dmi_table)) {
1003 		if (!ignore_dmi && !force)
1004 			return -ENODEV;
1005 
1006 		pr_info("not running on a supported Dell system.\n");
1007 		pr_info("vendor=%s, model=%s, version=%s\n",
1008 			i8k_get_dmi_data(DMI_SYS_VENDOR),
1009 			i8k_get_dmi_data(DMI_PRODUCT_NAME),
1010 			i8k_get_dmi_data(DMI_BIOS_VERSION));
1011 	}
1012 
1013 	if (dmi_check_system(i8k_blacklist_fan_type_dmi_table))
1014 		disallow_fan_type_call = true;
1015 
1016 	strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
1017 		sizeof(bios_version));
1018 	strlcpy(bios_machineid, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
1019 		sizeof(bios_machineid));
1020 
1021 	/*
1022 	 * Get SMM Dell signature
1023 	 */
1024 	if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
1025 	    i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
1026 		pr_err("unable to get SMM Dell signature\n");
1027 		if (!force)
1028 			return -ENODEV;
1029 	}
1030 
1031 	/*
1032 	 * Set fan multiplier and maximal fan speed from dmi config
1033 	 * Values specified in module parameters override values from dmi
1034 	 */
1035 	id = dmi_first_match(i8k_dmi_table);
1036 	if (id && id->driver_data) {
1037 		const struct i8k_config_data *conf = id->driver_data;
1038 		if (!fan_mult && conf->fan_mult)
1039 			fan_mult = conf->fan_mult;
1040 		if (!fan_max && conf->fan_max)
1041 			fan_max = conf->fan_max;
1042 	}
1043 
1044 	i8k_fan_max = fan_max ? : I8K_FAN_HIGH;	/* Must not be 0 */
1045 	i8k_pwm_mult = DIV_ROUND_UP(255, i8k_fan_max);
1046 
1047 	if (!fan_mult) {
1048 		/*
1049 		 * Autodetect fan multiplier based on nominal rpm
1050 		 * If fan reports rpm value too high then set multiplier to 1
1051 		 */
1052 		for (fan = 0; fan < 2; ++fan) {
1053 			ret = i8k_get_fan_nominal_speed(fan, i8k_fan_max);
1054 			if (ret < 0)
1055 				continue;
1056 			if (ret > I8K_FAN_MAX_RPM)
1057 				i8k_fan_mult = 1;
1058 			break;
1059 		}
1060 	} else {
1061 		/* Fan multiplier was specified in module param or in dmi */
1062 		i8k_fan_mult = fan_mult;
1063 	}
1064 
1065 	return 0;
1066 }
1067 
i8k_init(void)1068 static int __init i8k_init(void)
1069 {
1070 	int err;
1071 
1072 	/* Are we running on an supported laptop? */
1073 	if (i8k_probe())
1074 		return -ENODEV;
1075 
1076 	err = i8k_init_hwmon();
1077 	if (err)
1078 		return err;
1079 
1080 	i8k_init_procfs();
1081 	return 0;
1082 }
1083 
i8k_exit(void)1084 static void __exit i8k_exit(void)
1085 {
1086 	hwmon_device_unregister(i8k_hwmon_dev);
1087 	i8k_exit_procfs();
1088 }
1089 
1090 module_init(i8k_init);
1091 module_exit(i8k_exit);
1092