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/cpu.h>
16 #include <linux/delay.h>
17 #include <linux/err.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/types.h>
21 #include <linux/init.h>
22 #include <linux/proc_fs.h>
23 #include <linux/seq_file.h>
24 #include <linux/dmi.h>
25 #include <linux/capability.h>
26 #include <linux/mutex.h>
27 #include <linux/hwmon.h>
28 #include <linux/uaccess.h>
29 #include <linux/io.h>
30 #include <linux/sched.h>
31 #include <linux/ctype.h>
32 #include <linux/smp.h>
33
34 #include <linux/i8k.h>
35
36 #define I8K_SMM_FN_STATUS 0x0025
37 #define I8K_SMM_POWER_STATUS 0x0069
38 #define I8K_SMM_SET_FAN 0x01a3
39 #define I8K_SMM_GET_FAN 0x00a3
40 #define I8K_SMM_GET_SPEED 0x02a3
41 #define I8K_SMM_GET_FAN_TYPE 0x03a3
42 #define I8K_SMM_GET_NOM_SPEED 0x04a3
43 #define I8K_SMM_GET_TEMP 0x10a3
44 #define I8K_SMM_GET_TEMP_TYPE 0x11a3
45 #define I8K_SMM_GET_DELL_SIG1 0xfea3
46 #define I8K_SMM_GET_DELL_SIG2 0xffa3
47
48 #define I8K_FAN_MULT 30
49 #define I8K_FAN_MAX_RPM 30000
50 #define I8K_MAX_TEMP 127
51
52 #define I8K_FN_NONE 0x00
53 #define I8K_FN_UP 0x01
54 #define I8K_FN_DOWN 0x02
55 #define I8K_FN_MUTE 0x04
56 #define I8K_FN_MASK 0x07
57 #define I8K_FN_SHIFT 8
58
59 #define I8K_POWER_AC 0x05
60 #define I8K_POWER_BATTERY 0x01
61
62 #define DELL_SMM_NO_TEMP 10
63 #define DELL_SMM_NO_FANS 3
64
65 struct dell_smm_data {
66 struct mutex i8k_mutex; /* lock for sensors writes */
67 char bios_version[4];
68 char bios_machineid[16];
69 uint i8k_fan_mult;
70 uint i8k_pwm_mult;
71 uint i8k_fan_max;
72 bool disallow_fan_type_call;
73 bool disallow_fan_support;
74 unsigned int manual_fan;
75 unsigned int auto_fan;
76 int temp_type[DELL_SMM_NO_TEMP];
77 bool fan[DELL_SMM_NO_FANS];
78 int fan_type[DELL_SMM_NO_FANS];
79 };
80
81 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
82 MODULE_AUTHOR("Pali Rohár <pali@kernel.org>");
83 MODULE_DESCRIPTION("Dell laptop SMM BIOS hwmon driver");
84 MODULE_LICENSE("GPL");
85 MODULE_ALIAS("i8k");
86
87 static bool force;
88 module_param(force, bool, 0);
89 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
90
91 static bool ignore_dmi;
92 module_param(ignore_dmi, bool, 0);
93 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
94
95 #if IS_ENABLED(CONFIG_I8K)
96 static bool restricted = true;
97 module_param(restricted, bool, 0);
98 MODULE_PARM_DESC(restricted, "Restrict fan control and serial number to CAP_SYS_ADMIN (default: 1)");
99
100 static bool power_status;
101 module_param(power_status, bool, 0600);
102 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k (default: 0)");
103 #endif
104
105 static uint fan_mult;
106 module_param(fan_mult, uint, 0);
107 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with (default: autodetect)");
108
109 static uint fan_max;
110 module_param(fan_max, uint, 0);
111 MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autodetect)");
112
113 struct smm_regs {
114 unsigned int eax;
115 unsigned int ebx __packed;
116 unsigned int ecx __packed;
117 unsigned int edx __packed;
118 unsigned int esi __packed;
119 unsigned int edi __packed;
120 };
121
122 static const char * const temp_labels[] = {
123 "CPU",
124 "GPU",
125 "SODIMM",
126 "Other",
127 "Ambient",
128 "Other",
129 };
130
131 static const char * const fan_labels[] = {
132 "Processor Fan",
133 "Motherboard Fan",
134 "Video Fan",
135 "Power Supply Fan",
136 "Chipset Fan",
137 "Other Fan",
138 };
139
140 static const char * const docking_labels[] = {
141 "Docking Processor Fan",
142 "Docking Motherboard Fan",
143 "Docking Video Fan",
144 "Docking Power Supply Fan",
145 "Docking Chipset Fan",
146 "Docking Other Fan",
147 };
148
i8k_get_dmi_data(int field)149 static inline const char __init *i8k_get_dmi_data(int field)
150 {
151 const char *dmi_data = dmi_get_system_info(field);
152
153 return dmi_data && *dmi_data ? dmi_data : "?";
154 }
155
156 /*
157 * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
158 */
i8k_smm_func(void * par)159 static int i8k_smm_func(void *par)
160 {
161 ktime_t calltime = ktime_get();
162 struct smm_regs *regs = par;
163 int eax = regs->eax;
164 int ebx = regs->ebx;
165 long long duration;
166 int rc;
167
168 /* SMM requires CPU 0 */
169 if (smp_processor_id() != 0)
170 return -EBUSY;
171
172 #if defined(CONFIG_X86_64)
173 asm volatile("pushq %%rax\n\t"
174 "movl 0(%%rax),%%edx\n\t"
175 "pushq %%rdx\n\t"
176 "movl 4(%%rax),%%ebx\n\t"
177 "movl 8(%%rax),%%ecx\n\t"
178 "movl 12(%%rax),%%edx\n\t"
179 "movl 16(%%rax),%%esi\n\t"
180 "movl 20(%%rax),%%edi\n\t"
181 "popq %%rax\n\t"
182 "out %%al,$0xb2\n\t"
183 "out %%al,$0x84\n\t"
184 "xchgq %%rax,(%%rsp)\n\t"
185 "movl %%ebx,4(%%rax)\n\t"
186 "movl %%ecx,8(%%rax)\n\t"
187 "movl %%edx,12(%%rax)\n\t"
188 "movl %%esi,16(%%rax)\n\t"
189 "movl %%edi,20(%%rax)\n\t"
190 "popq %%rdx\n\t"
191 "movl %%edx,0(%%rax)\n\t"
192 "pushfq\n\t"
193 "popq %%rax\n\t"
194 "andl $1,%%eax\n"
195 : "=a"(rc)
196 : "a"(regs)
197 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
198 #else
199 asm volatile("pushl %%eax\n\t"
200 "movl 0(%%eax),%%edx\n\t"
201 "push %%edx\n\t"
202 "movl 4(%%eax),%%ebx\n\t"
203 "movl 8(%%eax),%%ecx\n\t"
204 "movl 12(%%eax),%%edx\n\t"
205 "movl 16(%%eax),%%esi\n\t"
206 "movl 20(%%eax),%%edi\n\t"
207 "popl %%eax\n\t"
208 "out %%al,$0xb2\n\t"
209 "out %%al,$0x84\n\t"
210 "xchgl %%eax,(%%esp)\n\t"
211 "movl %%ebx,4(%%eax)\n\t"
212 "movl %%ecx,8(%%eax)\n\t"
213 "movl %%edx,12(%%eax)\n\t"
214 "movl %%esi,16(%%eax)\n\t"
215 "movl %%edi,20(%%eax)\n\t"
216 "popl %%edx\n\t"
217 "movl %%edx,0(%%eax)\n\t"
218 "lahf\n\t"
219 "shrl $8,%%eax\n\t"
220 "andl $1,%%eax\n"
221 : "=a"(rc)
222 : "a"(regs)
223 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
224 #endif
225 if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
226 rc = -EINVAL;
227
228 duration = ktime_us_delta(ktime_get(), calltime);
229 pr_debug("smm(0x%.4x 0x%.4x) = 0x%.4x (took %7lld usecs)\n", eax, ebx,
230 (rc ? 0xffff : regs->eax & 0xffff), duration);
231
232 return rc;
233 }
234
235 /*
236 * Call the System Management Mode BIOS.
237 */
i8k_smm(struct smm_regs * regs)238 static int i8k_smm(struct smm_regs *regs)
239 {
240 int ret;
241
242 cpus_read_lock();
243 ret = smp_call_on_cpu(0, i8k_smm_func, regs, true);
244 cpus_read_unlock();
245
246 return ret;
247 }
248
249 /*
250 * Read the fan status.
251 */
i8k_get_fan_status(const struct dell_smm_data * data,int fan)252 static int i8k_get_fan_status(const struct dell_smm_data *data, int fan)
253 {
254 struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
255
256 if (data->disallow_fan_support)
257 return -EINVAL;
258
259 regs.ebx = fan & 0xff;
260 return i8k_smm(®s) ? : regs.eax & 0xff;
261 }
262
263 /*
264 * Read the fan speed in RPM.
265 */
i8k_get_fan_speed(const struct dell_smm_data * data,int fan)266 static int i8k_get_fan_speed(const struct dell_smm_data *data, int fan)
267 {
268 struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
269
270 if (data->disallow_fan_support)
271 return -EINVAL;
272
273 regs.ebx = fan & 0xff;
274 return i8k_smm(®s) ? : (regs.eax & 0xffff) * data->i8k_fan_mult;
275 }
276
277 /*
278 * Read the fan type.
279 */
_i8k_get_fan_type(const struct dell_smm_data * data,int fan)280 static int _i8k_get_fan_type(const struct dell_smm_data *data, int fan)
281 {
282 struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_TYPE, };
283
284 if (data->disallow_fan_support || data->disallow_fan_type_call)
285 return -EINVAL;
286
287 regs.ebx = fan & 0xff;
288 return i8k_smm(®s) ? : regs.eax & 0xff;
289 }
290
i8k_get_fan_type(struct dell_smm_data * data,int fan)291 static int i8k_get_fan_type(struct dell_smm_data *data, int fan)
292 {
293 /* I8K_SMM_GET_FAN_TYPE SMM call is expensive, so cache values */
294 if (data->fan_type[fan] == INT_MIN)
295 data->fan_type[fan] = _i8k_get_fan_type(data, fan);
296
297 return data->fan_type[fan];
298 }
299
300 /*
301 * Read the fan nominal rpm for specific fan speed.
302 */
i8k_get_fan_nominal_speed(const struct dell_smm_data * data,int fan,int speed)303 static int __init i8k_get_fan_nominal_speed(const struct dell_smm_data *data, int fan, int speed)
304 {
305 struct smm_regs regs = { .eax = I8K_SMM_GET_NOM_SPEED, };
306
307 if (data->disallow_fan_support)
308 return -EINVAL;
309
310 regs.ebx = (fan & 0xff) | (speed << 8);
311 return i8k_smm(®s) ? : (regs.eax & 0xffff) * data->i8k_fan_mult;
312 }
313
314 /*
315 * Enable or disable automatic BIOS fan control support
316 */
i8k_enable_fan_auto_mode(const struct dell_smm_data * data,bool enable)317 static int i8k_enable_fan_auto_mode(const struct dell_smm_data *data, bool enable)
318 {
319 struct smm_regs regs = { };
320
321 if (data->disallow_fan_support)
322 return -EINVAL;
323
324 regs.eax = enable ? data->auto_fan : data->manual_fan;
325 return i8k_smm(®s);
326 }
327
328 /*
329 * Set the fan speed (off, low, high, ...).
330 */
i8k_set_fan(const struct dell_smm_data * data,int fan,int speed)331 static int i8k_set_fan(const struct dell_smm_data *data, int fan, int speed)
332 {
333 struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
334
335 if (data->disallow_fan_support)
336 return -EINVAL;
337
338 speed = (speed < 0) ? 0 : ((speed > data->i8k_fan_max) ? data->i8k_fan_max : speed);
339 regs.ebx = (fan & 0xff) | (speed << 8);
340
341 return i8k_smm(®s);
342 }
343
i8k_get_temp_type(int sensor)344 static int __init i8k_get_temp_type(int sensor)
345 {
346 struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP_TYPE, };
347
348 regs.ebx = sensor & 0xff;
349 return i8k_smm(®s) ? : regs.eax & 0xff;
350 }
351
352 /*
353 * Read the cpu temperature.
354 */
_i8k_get_temp(int sensor)355 static int _i8k_get_temp(int sensor)
356 {
357 struct smm_regs regs = {
358 .eax = I8K_SMM_GET_TEMP,
359 .ebx = sensor & 0xff,
360 };
361
362 return i8k_smm(®s) ? : regs.eax & 0xff;
363 }
364
i8k_get_temp(int sensor)365 static int i8k_get_temp(int sensor)
366 {
367 int temp = _i8k_get_temp(sensor);
368
369 /*
370 * Sometimes the temperature sensor returns 0x99, which is out of range.
371 * In this case we retry (once) before returning an error.
372 # 1003655137 00000058 00005a4b
373 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
374 # 1003655139 00000054 00005c52
375 */
376 if (temp == 0x99) {
377 msleep(100);
378 temp = _i8k_get_temp(sensor);
379 }
380 /*
381 * Return -ENODATA for all invalid temperatures.
382 *
383 * Known instances are the 0x99 value as seen above as well as
384 * 0xc1 (193), which may be returned when trying to read the GPU
385 * temperature if the system supports a GPU and it is currently
386 * turned off.
387 */
388 if (temp > I8K_MAX_TEMP)
389 return -ENODATA;
390
391 return temp;
392 }
393
i8k_get_dell_signature(int req_fn)394 static int __init i8k_get_dell_signature(int req_fn)
395 {
396 struct smm_regs regs = { .eax = req_fn, };
397 int rc;
398
399 rc = i8k_smm(®s);
400 if (rc < 0)
401 return rc;
402
403 return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
404 }
405
406 #if IS_ENABLED(CONFIG_I8K)
407
408 /*
409 * Read the Fn key status.
410 */
i8k_get_fn_status(void)411 static int i8k_get_fn_status(void)
412 {
413 struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
414 int rc;
415
416 rc = i8k_smm(®s);
417 if (rc < 0)
418 return rc;
419
420 switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
421 case I8K_FN_UP:
422 return I8K_VOL_UP;
423 case I8K_FN_DOWN:
424 return I8K_VOL_DOWN;
425 case I8K_FN_MUTE:
426 return I8K_VOL_MUTE;
427 default:
428 return 0;
429 }
430 }
431
432 /*
433 * Read the power status.
434 */
i8k_get_power_status(void)435 static int i8k_get_power_status(void)
436 {
437 struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
438 int rc;
439
440 rc = i8k_smm(®s);
441 if (rc < 0)
442 return rc;
443
444 return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
445 }
446
447 /*
448 * Procfs interface
449 */
450
451 static int
i8k_ioctl_unlocked(struct file * fp,struct dell_smm_data * data,unsigned int cmd,unsigned long arg)452 i8k_ioctl_unlocked(struct file *fp, struct dell_smm_data *data, unsigned int cmd, unsigned long arg)
453 {
454 int val = 0;
455 int speed, err;
456 unsigned char buff[16];
457 int __user *argp = (int __user *)arg;
458
459 if (!argp)
460 return -EINVAL;
461
462 switch (cmd) {
463 case I8K_BIOS_VERSION:
464 if (!isdigit(data->bios_version[0]) || !isdigit(data->bios_version[1]) ||
465 !isdigit(data->bios_version[2]))
466 return -EINVAL;
467
468 val = (data->bios_version[0] << 16) |
469 (data->bios_version[1] << 8) | data->bios_version[2];
470 break;
471
472 case I8K_MACHINE_ID:
473 if (restricted && !capable(CAP_SYS_ADMIN))
474 return -EPERM;
475
476 memset(buff, 0, sizeof(buff));
477 strscpy(buff, data->bios_machineid, sizeof(buff));
478 break;
479
480 case I8K_FN_STATUS:
481 val = i8k_get_fn_status();
482 break;
483
484 case I8K_POWER_STATUS:
485 val = i8k_get_power_status();
486 break;
487
488 case I8K_GET_TEMP:
489 val = i8k_get_temp(0);
490 break;
491
492 case I8K_GET_SPEED:
493 if (copy_from_user(&val, argp, sizeof(int)))
494 return -EFAULT;
495
496 val = i8k_get_fan_speed(data, val);
497 break;
498
499 case I8K_GET_FAN:
500 if (copy_from_user(&val, argp, sizeof(int)))
501 return -EFAULT;
502
503 val = i8k_get_fan_status(data, val);
504 break;
505
506 case I8K_SET_FAN:
507 if (restricted && !capable(CAP_SYS_ADMIN))
508 return -EPERM;
509
510 if (copy_from_user(&val, argp, sizeof(int)))
511 return -EFAULT;
512
513 if (copy_from_user(&speed, argp + 1, sizeof(int)))
514 return -EFAULT;
515
516 err = i8k_set_fan(data, val, speed);
517 if (err < 0)
518 return err;
519
520 val = i8k_get_fan_status(data, val);
521 break;
522
523 default:
524 return -EINVAL;
525 }
526
527 if (val < 0)
528 return val;
529
530 switch (cmd) {
531 case I8K_BIOS_VERSION:
532 if (copy_to_user(argp, &val, 4))
533 return -EFAULT;
534
535 break;
536 case I8K_MACHINE_ID:
537 if (copy_to_user(argp, buff, 16))
538 return -EFAULT;
539
540 break;
541 default:
542 if (copy_to_user(argp, &val, sizeof(int)))
543 return -EFAULT;
544
545 break;
546 }
547
548 return 0;
549 }
550
i8k_ioctl(struct file * fp,unsigned int cmd,unsigned long arg)551 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
552 {
553 struct dell_smm_data *data = PDE_DATA(file_inode(fp));
554 long ret;
555
556 mutex_lock(&data->i8k_mutex);
557 ret = i8k_ioctl_unlocked(fp, data, cmd, arg);
558 mutex_unlock(&data->i8k_mutex);
559
560 return ret;
561 }
562
563 /*
564 * Print the information for /proc/i8k.
565 */
i8k_proc_show(struct seq_file * seq,void * offset)566 static int i8k_proc_show(struct seq_file *seq, void *offset)
567 {
568 struct dell_smm_data *data = seq->private;
569 int fn_key, cpu_temp, ac_power;
570 int left_fan, right_fan, left_speed, right_speed;
571
572 cpu_temp = i8k_get_temp(0); /* 11100 µs */
573 left_fan = i8k_get_fan_status(data, I8K_FAN_LEFT); /* 580 µs */
574 right_fan = i8k_get_fan_status(data, I8K_FAN_RIGHT); /* 580 µs */
575 left_speed = i8k_get_fan_speed(data, I8K_FAN_LEFT); /* 580 µs */
576 right_speed = i8k_get_fan_speed(data, I8K_FAN_RIGHT); /* 580 µs */
577 fn_key = i8k_get_fn_status(); /* 750 µs */
578 if (power_status)
579 ac_power = i8k_get_power_status(); /* 14700 µs */
580 else
581 ac_power = -1;
582
583 /*
584 * Info:
585 *
586 * 1) Format version (this will change if format changes)
587 * 2) BIOS version
588 * 3) BIOS machine ID
589 * 4) Cpu temperature
590 * 5) Left fan status
591 * 6) Right fan status
592 * 7) Left fan speed
593 * 8) Right fan speed
594 * 9) AC power
595 * 10) Fn Key status
596 */
597 seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
598 I8K_PROC_FMT,
599 data->bios_version,
600 (restricted && !capable(CAP_SYS_ADMIN)) ? "-1" : data->bios_machineid,
601 cpu_temp,
602 left_fan, right_fan, left_speed, right_speed,
603 ac_power, fn_key);
604
605 return 0;
606 }
607
i8k_open_fs(struct inode * inode,struct file * file)608 static int i8k_open_fs(struct inode *inode, struct file *file)
609 {
610 return single_open(file, i8k_proc_show, PDE_DATA(inode));
611 }
612
613 static const struct proc_ops i8k_proc_ops = {
614 .proc_open = i8k_open_fs,
615 .proc_read = seq_read,
616 .proc_lseek = seq_lseek,
617 .proc_release = single_release,
618 .proc_ioctl = i8k_ioctl,
619 };
620
i8k_exit_procfs(void * param)621 static void i8k_exit_procfs(void *param)
622 {
623 remove_proc_entry("i8k", NULL);
624 }
625
i8k_init_procfs(struct device * dev)626 static void __init i8k_init_procfs(struct device *dev)
627 {
628 struct dell_smm_data *data = dev_get_drvdata(dev);
629
630 /* Only register exit function if creation was successful */
631 if (proc_create_data("i8k", 0, NULL, &i8k_proc_ops, data))
632 devm_add_action_or_reset(dev, i8k_exit_procfs, NULL);
633 }
634
635 #else
636
i8k_init_procfs(struct device * dev)637 static void __init i8k_init_procfs(struct device *dev)
638 {
639 }
640
641 #endif
642
643 /*
644 * Hwmon interface
645 */
646
dell_smm_is_visible(const void * drvdata,enum hwmon_sensor_types type,u32 attr,int channel)647 static umode_t dell_smm_is_visible(const void *drvdata, enum hwmon_sensor_types type, u32 attr,
648 int channel)
649 {
650 const struct dell_smm_data *data = drvdata;
651
652 switch (type) {
653 case hwmon_temp:
654 switch (attr) {
655 case hwmon_temp_input:
656 case hwmon_temp_label:
657 if (data->temp_type[channel] >= 0)
658 return 0444;
659
660 break;
661 default:
662 break;
663 }
664 break;
665 case hwmon_fan:
666 if (data->disallow_fan_support)
667 break;
668
669 switch (attr) {
670 case hwmon_fan_input:
671 if (data->fan[channel])
672 return 0444;
673
674 break;
675 case hwmon_fan_label:
676 if (data->fan[channel] && !data->disallow_fan_type_call)
677 return 0444;
678
679 break;
680 default:
681 break;
682 }
683 break;
684 case hwmon_pwm:
685 if (data->disallow_fan_support)
686 break;
687
688 switch (attr) {
689 case hwmon_pwm_input:
690 if (data->fan[channel])
691 return 0644;
692
693 break;
694 case hwmon_pwm_enable:
695 if (data->auto_fan)
696 /*
697 * There is no command for retrieve the current status
698 * from BIOS, and userspace/firmware itself can change
699 * it.
700 * Thus we can only provide write-only access for now.
701 */
702 return 0200;
703
704 break;
705 default:
706 break;
707 }
708 break;
709 default:
710 break;
711 }
712
713 return 0;
714 }
715
dell_smm_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)716 static int dell_smm_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
717 long *val)
718 {
719 struct dell_smm_data *data = dev_get_drvdata(dev);
720 int ret;
721
722 switch (type) {
723 case hwmon_temp:
724 switch (attr) {
725 case hwmon_temp_input:
726 ret = i8k_get_temp(channel);
727 if (ret < 0)
728 return ret;
729
730 *val = ret * 1000;
731
732 return 0;
733 default:
734 break;
735 }
736 break;
737 case hwmon_fan:
738 switch (attr) {
739 case hwmon_fan_input:
740 ret = i8k_get_fan_speed(data, channel);
741 if (ret < 0)
742 return ret;
743
744 *val = ret;
745
746 return 0;
747 default:
748 break;
749 }
750 break;
751 case hwmon_pwm:
752 switch (attr) {
753 case hwmon_pwm_input:
754 ret = i8k_get_fan_status(data, channel);
755 if (ret < 0)
756 return ret;
757
758 *val = clamp_val(ret * data->i8k_pwm_mult, 0, 255);
759
760 return 0;
761 default:
762 break;
763 }
764 break;
765 default:
766 break;
767 }
768
769 return -EOPNOTSUPP;
770 }
771
dell_smm_fan_label(struct dell_smm_data * data,int channel)772 static const char *dell_smm_fan_label(struct dell_smm_data *data, int channel)
773 {
774 bool dock = false;
775 int type = i8k_get_fan_type(data, channel);
776
777 if (type < 0)
778 return ERR_PTR(type);
779
780 if (type & 0x10) {
781 dock = true;
782 type &= 0x0F;
783 }
784
785 if (type >= ARRAY_SIZE(fan_labels))
786 type = ARRAY_SIZE(fan_labels) - 1;
787
788 return dock ? docking_labels[type] : fan_labels[type];
789 }
790
dell_smm_read_string(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,const char ** str)791 static int dell_smm_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
792 int channel, const char **str)
793 {
794 struct dell_smm_data *data = dev_get_drvdata(dev);
795
796 switch (type) {
797 case hwmon_temp:
798 switch (attr) {
799 case hwmon_temp_label:
800 *str = temp_labels[data->temp_type[channel]];
801 return 0;
802 default:
803 break;
804 }
805 break;
806 case hwmon_fan:
807 switch (attr) {
808 case hwmon_fan_label:
809 *str = dell_smm_fan_label(data, channel);
810 return PTR_ERR_OR_ZERO(*str);
811 default:
812 break;
813 }
814 break;
815 default:
816 break;
817 }
818
819 return -EOPNOTSUPP;
820 }
821
dell_smm_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)822 static int dell_smm_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
823 long val)
824 {
825 struct dell_smm_data *data = dev_get_drvdata(dev);
826 unsigned long pwm;
827 bool enable;
828 int err;
829
830 switch (type) {
831 case hwmon_pwm:
832 switch (attr) {
833 case hwmon_pwm_input:
834 pwm = clamp_val(DIV_ROUND_CLOSEST(val, data->i8k_pwm_mult), 0,
835 data->i8k_fan_max);
836
837 mutex_lock(&data->i8k_mutex);
838 err = i8k_set_fan(data, channel, pwm);
839 mutex_unlock(&data->i8k_mutex);
840
841 if (err < 0)
842 return err;
843
844 return 0;
845 case hwmon_pwm_enable:
846 if (!val)
847 return -EINVAL;
848
849 if (val == 1)
850 enable = false;
851 else
852 enable = true;
853
854 mutex_lock(&data->i8k_mutex);
855 err = i8k_enable_fan_auto_mode(data, enable);
856 mutex_unlock(&data->i8k_mutex);
857
858 if (err < 0)
859 return err;
860
861 return 0;
862 default:
863 break;
864 }
865 break;
866 default:
867 break;
868 }
869
870 return -EOPNOTSUPP;
871 }
872
873 static const struct hwmon_ops dell_smm_ops = {
874 .is_visible = dell_smm_is_visible,
875 .read = dell_smm_read,
876 .read_string = dell_smm_read_string,
877 .write = dell_smm_write,
878 };
879
880 static const struct hwmon_channel_info *dell_smm_info[] = {
881 HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
882 HWMON_CHANNEL_INFO(temp,
883 HWMON_T_INPUT | HWMON_T_LABEL,
884 HWMON_T_INPUT | HWMON_T_LABEL,
885 HWMON_T_INPUT | HWMON_T_LABEL,
886 HWMON_T_INPUT | HWMON_T_LABEL,
887 HWMON_T_INPUT | HWMON_T_LABEL,
888 HWMON_T_INPUT | HWMON_T_LABEL,
889 HWMON_T_INPUT | HWMON_T_LABEL,
890 HWMON_T_INPUT | HWMON_T_LABEL,
891 HWMON_T_INPUT | HWMON_T_LABEL,
892 HWMON_T_INPUT | HWMON_T_LABEL
893 ),
894 HWMON_CHANNEL_INFO(fan,
895 HWMON_F_INPUT | HWMON_F_LABEL,
896 HWMON_F_INPUT | HWMON_F_LABEL,
897 HWMON_F_INPUT | HWMON_F_LABEL
898 ),
899 HWMON_CHANNEL_INFO(pwm,
900 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
901 HWMON_PWM_INPUT,
902 HWMON_PWM_INPUT
903 ),
904 NULL
905 };
906
907 static const struct hwmon_chip_info dell_smm_chip_info = {
908 .ops = &dell_smm_ops,
909 .info = dell_smm_info,
910 };
911
dell_smm_init_hwmon(struct device * dev)912 static int __init dell_smm_init_hwmon(struct device *dev)
913 {
914 struct dell_smm_data *data = dev_get_drvdata(dev);
915 struct device *dell_smm_hwmon_dev;
916 int i, err;
917
918 for (i = 0; i < DELL_SMM_NO_TEMP; i++) {
919 data->temp_type[i] = i8k_get_temp_type(i);
920 if (data->temp_type[i] < 0)
921 continue;
922
923 if (data->temp_type[i] >= ARRAY_SIZE(temp_labels))
924 data->temp_type[i] = ARRAY_SIZE(temp_labels) - 1;
925 }
926
927 for (i = 0; i < DELL_SMM_NO_FANS; i++) {
928 data->fan_type[i] = INT_MIN;
929 err = i8k_get_fan_status(data, i);
930 if (err < 0)
931 err = i8k_get_fan_type(data, i);
932 if (err >= 0)
933 data->fan[i] = true;
934 }
935
936 dell_smm_hwmon_dev = devm_hwmon_device_register_with_info(dev, "dell_smm", data,
937 &dell_smm_chip_info, NULL);
938
939 return PTR_ERR_OR_ZERO(dell_smm_hwmon_dev);
940 }
941
942 struct i8k_config_data {
943 uint fan_mult;
944 uint fan_max;
945 };
946
947 enum i8k_configs {
948 DELL_LATITUDE_D520,
949 DELL_PRECISION_490,
950 DELL_STUDIO,
951 DELL_XPS,
952 };
953
954 static const struct i8k_config_data i8k_config_data[] __initconst = {
955 [DELL_LATITUDE_D520] = {
956 .fan_mult = 1,
957 .fan_max = I8K_FAN_TURBO,
958 },
959 [DELL_PRECISION_490] = {
960 .fan_mult = 1,
961 .fan_max = I8K_FAN_TURBO,
962 },
963 [DELL_STUDIO] = {
964 .fan_mult = 1,
965 .fan_max = I8K_FAN_HIGH,
966 },
967 [DELL_XPS] = {
968 .fan_mult = 1,
969 .fan_max = I8K_FAN_HIGH,
970 },
971 };
972
973 static const struct dmi_system_id i8k_dmi_table[] __initconst = {
974 {
975 .ident = "Dell Inspiron",
976 .matches = {
977 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
978 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
979 },
980 },
981 {
982 .ident = "Dell Latitude",
983 .matches = {
984 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
985 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
986 },
987 },
988 {
989 .ident = "Dell Inspiron 2",
990 .matches = {
991 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
992 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
993 },
994 },
995 {
996 .ident = "Dell Latitude D520",
997 .matches = {
998 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
999 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
1000 },
1001 .driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
1002 },
1003 {
1004 .ident = "Dell Latitude 2",
1005 .matches = {
1006 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1007 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
1008 },
1009 },
1010 { /* UK Inspiron 6400 */
1011 .ident = "Dell Inspiron 3",
1012 .matches = {
1013 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1014 DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
1015 },
1016 },
1017 {
1018 .ident = "Dell Inspiron 3",
1019 .matches = {
1020 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1021 DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
1022 },
1023 },
1024 {
1025 .ident = "Dell Precision 490",
1026 .matches = {
1027 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1028 DMI_MATCH(DMI_PRODUCT_NAME,
1029 "Precision WorkStation 490"),
1030 },
1031 .driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
1032 },
1033 {
1034 .ident = "Dell Precision",
1035 .matches = {
1036 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1037 DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
1038 },
1039 },
1040 {
1041 .ident = "Dell Vostro",
1042 .matches = {
1043 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1044 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
1045 },
1046 },
1047 {
1048 .ident = "Dell Studio",
1049 .matches = {
1050 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1051 DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
1052 },
1053 .driver_data = (void *)&i8k_config_data[DELL_STUDIO],
1054 },
1055 {
1056 .ident = "Dell XPS M140",
1057 .matches = {
1058 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1059 DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
1060 },
1061 .driver_data = (void *)&i8k_config_data[DELL_XPS],
1062 },
1063 {
1064 .ident = "Dell XPS",
1065 .matches = {
1066 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1067 DMI_MATCH(DMI_PRODUCT_NAME, "XPS"),
1068 },
1069 },
1070 { }
1071 };
1072
1073 MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
1074
1075 /*
1076 * On some machines once I8K_SMM_GET_FAN_TYPE is issued then CPU fan speed
1077 * randomly going up and down due to bug in Dell SMM or BIOS. Here is blacklist
1078 * of affected Dell machines for which we disallow I8K_SMM_GET_FAN_TYPE call.
1079 * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=100121
1080 */
1081 static const struct dmi_system_id i8k_blacklist_fan_type_dmi_table[] __initconst = {
1082 {
1083 .ident = "Dell Studio XPS 8000",
1084 .matches = {
1085 DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1086 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8000"),
1087 },
1088 },
1089 {
1090 .ident = "Dell Studio XPS 8100",
1091 .matches = {
1092 DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1093 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8100"),
1094 },
1095 },
1096 {
1097 .ident = "Dell Inspiron 580",
1098 .matches = {
1099 DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1100 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 580 "),
1101 },
1102 },
1103 { }
1104 };
1105
1106 /*
1107 * On some machines all fan related SMM functions implemented by Dell BIOS
1108 * firmware freeze kernel for about 500ms. Until Dell fixes these problems fan
1109 * support for affected blacklisted Dell machines stay disabled.
1110 * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=195751
1111 */
1112 static const struct dmi_system_id i8k_blacklist_fan_support_dmi_table[] __initconst = {
1113 {
1114 .ident = "Dell Inspiron 7720",
1115 .matches = {
1116 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1117 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 7720"),
1118 },
1119 },
1120 {
1121 .ident = "Dell Vostro 3360",
1122 .matches = {
1123 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1124 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Vostro 3360"),
1125 },
1126 },
1127 {
1128 .ident = "Dell XPS13 9333",
1129 .matches = {
1130 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1131 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS13 9333"),
1132 },
1133 },
1134 {
1135 .ident = "Dell XPS 15 L502X",
1136 .matches = {
1137 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1138 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L502X"),
1139 },
1140 },
1141 { }
1142 };
1143
1144 struct i8k_fan_control_data {
1145 unsigned int manual_fan;
1146 unsigned int auto_fan;
1147 };
1148
1149 enum i8k_fan_controls {
1150 I8K_FAN_34A3_35A3,
1151 };
1152
1153 static const struct i8k_fan_control_data i8k_fan_control_data[] __initconst = {
1154 [I8K_FAN_34A3_35A3] = {
1155 .manual_fan = 0x34a3,
1156 .auto_fan = 0x35a3,
1157 },
1158 };
1159
1160 static const struct dmi_system_id i8k_whitelist_fan_control[] __initconst = {
1161 {
1162 .ident = "Dell Latitude 5480",
1163 .matches = {
1164 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1165 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude 5480"),
1166 },
1167 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1168 },
1169 {
1170 .ident = "Dell Latitude E6440",
1171 .matches = {
1172 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1173 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E6440"),
1174 },
1175 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1176 },
1177 {
1178 .ident = "Dell Latitude E7440",
1179 .matches = {
1180 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1181 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E7440"),
1182 },
1183 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1184 },
1185 {
1186 .ident = "Dell Precision 5530",
1187 .matches = {
1188 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1189 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 5530"),
1190 },
1191 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1192 },
1193 {
1194 .ident = "Dell Precision 7510",
1195 .matches = {
1196 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1197 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
1198 },
1199 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1200 },
1201 {
1202 .ident = "Dell XPS 13 7390",
1203 .matches = {
1204 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1205 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS 13 7390"),
1206 },
1207 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1208 },
1209 { }
1210 };
1211
dell_smm_probe(struct platform_device * pdev)1212 static int __init dell_smm_probe(struct platform_device *pdev)
1213 {
1214 struct dell_smm_data *data;
1215 const struct dmi_system_id *id, *fan_control;
1216 int fan, ret;
1217
1218 data = devm_kzalloc(&pdev->dev, sizeof(struct dell_smm_data), GFP_KERNEL);
1219 if (!data)
1220 return -ENOMEM;
1221
1222 mutex_init(&data->i8k_mutex);
1223 data->i8k_fan_mult = I8K_FAN_MULT;
1224 data->i8k_fan_max = I8K_FAN_HIGH;
1225 platform_set_drvdata(pdev, data);
1226
1227 if (dmi_check_system(i8k_blacklist_fan_support_dmi_table)) {
1228 dev_warn(&pdev->dev, "broken Dell BIOS detected, disallow fan support\n");
1229 if (!force)
1230 data->disallow_fan_support = true;
1231 }
1232
1233 if (dmi_check_system(i8k_blacklist_fan_type_dmi_table)) {
1234 dev_warn(&pdev->dev, "broken Dell BIOS detected, disallow fan type call\n");
1235 if (!force)
1236 data->disallow_fan_type_call = true;
1237 }
1238
1239 strscpy(data->bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
1240 sizeof(data->bios_version));
1241 strscpy(data->bios_machineid, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
1242 sizeof(data->bios_machineid));
1243
1244 /*
1245 * Set fan multiplier and maximal fan speed from dmi config
1246 * Values specified in module parameters override values from dmi
1247 */
1248 id = dmi_first_match(i8k_dmi_table);
1249 if (id && id->driver_data) {
1250 const struct i8k_config_data *conf = id->driver_data;
1251
1252 if (!fan_mult && conf->fan_mult)
1253 fan_mult = conf->fan_mult;
1254
1255 if (!fan_max && conf->fan_max)
1256 fan_max = conf->fan_max;
1257 }
1258
1259 data->i8k_fan_max = fan_max ? : I8K_FAN_HIGH; /* Must not be 0 */
1260 data->i8k_pwm_mult = DIV_ROUND_UP(255, data->i8k_fan_max);
1261
1262 fan_control = dmi_first_match(i8k_whitelist_fan_control);
1263 if (fan_control && fan_control->driver_data) {
1264 const struct i8k_fan_control_data *control = fan_control->driver_data;
1265
1266 data->manual_fan = control->manual_fan;
1267 data->auto_fan = control->auto_fan;
1268 dev_info(&pdev->dev, "enabling support for setting automatic/manual fan control\n");
1269 }
1270
1271 if (!fan_mult) {
1272 /*
1273 * Autodetect fan multiplier based on nominal rpm
1274 * If fan reports rpm value too high then set multiplier to 1
1275 */
1276 for (fan = 0; fan < DELL_SMM_NO_FANS; ++fan) {
1277 ret = i8k_get_fan_nominal_speed(data, fan, data->i8k_fan_max);
1278 if (ret < 0)
1279 continue;
1280
1281 if (ret > I8K_FAN_MAX_RPM)
1282 data->i8k_fan_mult = 1;
1283 break;
1284 }
1285 } else {
1286 /* Fan multiplier was specified in module param or in dmi */
1287 data->i8k_fan_mult = fan_mult;
1288 }
1289
1290 ret = dell_smm_init_hwmon(&pdev->dev);
1291 if (ret)
1292 return ret;
1293
1294 i8k_init_procfs(&pdev->dev);
1295
1296 return 0;
1297 }
1298
1299 static struct platform_driver dell_smm_driver = {
1300 .driver = {
1301 .name = KBUILD_MODNAME,
1302 },
1303 };
1304
1305 static struct platform_device *dell_smm_device;
1306
1307 /*
1308 * Probe for the presence of a supported laptop.
1309 */
i8k_init(void)1310 static int __init i8k_init(void)
1311 {
1312 /*
1313 * Get DMI information
1314 */
1315 if (!dmi_check_system(i8k_dmi_table)) {
1316 if (!ignore_dmi && !force)
1317 return -ENODEV;
1318
1319 pr_info("not running on a supported Dell system.\n");
1320 pr_info("vendor=%s, model=%s, version=%s\n",
1321 i8k_get_dmi_data(DMI_SYS_VENDOR),
1322 i8k_get_dmi_data(DMI_PRODUCT_NAME),
1323 i8k_get_dmi_data(DMI_BIOS_VERSION));
1324 }
1325
1326 /*
1327 * Get SMM Dell signature
1328 */
1329 if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
1330 i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
1331 pr_err("unable to get SMM Dell signature\n");
1332 if (!force)
1333 return -ENODEV;
1334 }
1335
1336 dell_smm_device = platform_create_bundle(&dell_smm_driver, dell_smm_probe, NULL, 0, NULL,
1337 0);
1338
1339 return PTR_ERR_OR_ZERO(dell_smm_device);
1340 }
1341
i8k_exit(void)1342 static void __exit i8k_exit(void)
1343 {
1344 platform_device_unregister(dell_smm_device);
1345 platform_driver_unregister(&dell_smm_driver);
1346 }
1347
1348 module_init(i8k_init);
1349 module_exit(i8k_exit);
1350