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). Returns the new fan status.
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) ? : i8k_get_fan_status(data, fan);
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;
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 val = i8k_set_fan(data, val, speed);
517 break;
518
519 default:
520 return -EINVAL;
521 }
522
523 if (val < 0)
524 return val;
525
526 switch (cmd) {
527 case I8K_BIOS_VERSION:
528 if (copy_to_user(argp, &val, 4))
529 return -EFAULT;
530
531 break;
532 case I8K_MACHINE_ID:
533 if (copy_to_user(argp, buff, 16))
534 return -EFAULT;
535
536 break;
537 default:
538 if (copy_to_user(argp, &val, sizeof(int)))
539 return -EFAULT;
540
541 break;
542 }
543
544 return 0;
545 }
546
i8k_ioctl(struct file * fp,unsigned int cmd,unsigned long arg)547 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
548 {
549 struct dell_smm_data *data = PDE_DATA(file_inode(fp));
550 long ret;
551
552 mutex_lock(&data->i8k_mutex);
553 ret = i8k_ioctl_unlocked(fp, data, cmd, arg);
554 mutex_unlock(&data->i8k_mutex);
555
556 return ret;
557 }
558
559 /*
560 * Print the information for /proc/i8k.
561 */
i8k_proc_show(struct seq_file * seq,void * offset)562 static int i8k_proc_show(struct seq_file *seq, void *offset)
563 {
564 struct dell_smm_data *data = seq->private;
565 int fn_key, cpu_temp, ac_power;
566 int left_fan, right_fan, left_speed, right_speed;
567
568 cpu_temp = i8k_get_temp(0); /* 11100 µs */
569 left_fan = i8k_get_fan_status(data, I8K_FAN_LEFT); /* 580 µs */
570 right_fan = i8k_get_fan_status(data, I8K_FAN_RIGHT); /* 580 µs */
571 left_speed = i8k_get_fan_speed(data, I8K_FAN_LEFT); /* 580 µs */
572 right_speed = i8k_get_fan_speed(data, I8K_FAN_RIGHT); /* 580 µs */
573 fn_key = i8k_get_fn_status(); /* 750 µs */
574 if (power_status)
575 ac_power = i8k_get_power_status(); /* 14700 µs */
576 else
577 ac_power = -1;
578
579 /*
580 * Info:
581 *
582 * 1) Format version (this will change if format changes)
583 * 2) BIOS version
584 * 3) BIOS machine ID
585 * 4) Cpu temperature
586 * 5) Left fan status
587 * 6) Right fan status
588 * 7) Left fan speed
589 * 8) Right fan speed
590 * 9) AC power
591 * 10) Fn Key status
592 */
593 seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
594 I8K_PROC_FMT,
595 data->bios_version,
596 (restricted && !capable(CAP_SYS_ADMIN)) ? "-1" : data->bios_machineid,
597 cpu_temp,
598 left_fan, right_fan, left_speed, right_speed,
599 ac_power, fn_key);
600
601 return 0;
602 }
603
i8k_open_fs(struct inode * inode,struct file * file)604 static int i8k_open_fs(struct inode *inode, struct file *file)
605 {
606 return single_open(file, i8k_proc_show, PDE_DATA(inode));
607 }
608
609 static const struct proc_ops i8k_proc_ops = {
610 .proc_open = i8k_open_fs,
611 .proc_read = seq_read,
612 .proc_lseek = seq_lseek,
613 .proc_release = single_release,
614 .proc_ioctl = i8k_ioctl,
615 };
616
i8k_exit_procfs(void * param)617 static void i8k_exit_procfs(void *param)
618 {
619 remove_proc_entry("i8k", NULL);
620 }
621
i8k_init_procfs(struct device * dev)622 static void __init i8k_init_procfs(struct device *dev)
623 {
624 struct dell_smm_data *data = dev_get_drvdata(dev);
625
626 /* Register the proc entry */
627 proc_create_data("i8k", 0, NULL, &i8k_proc_ops, data);
628
629 devm_add_action_or_reset(dev, i8k_exit_procfs, NULL);
630 }
631
632 #else
633
i8k_init_procfs(struct device * dev)634 static void __init i8k_init_procfs(struct device *dev)
635 {
636 }
637
638 #endif
639
640 /*
641 * Hwmon interface
642 */
643
dell_smm_is_visible(const void * drvdata,enum hwmon_sensor_types type,u32 attr,int channel)644 static umode_t dell_smm_is_visible(const void *drvdata, enum hwmon_sensor_types type, u32 attr,
645 int channel)
646 {
647 const struct dell_smm_data *data = drvdata;
648
649 switch (type) {
650 case hwmon_temp:
651 switch (attr) {
652 case hwmon_temp_input:
653 case hwmon_temp_label:
654 if (data->temp_type[channel] >= 0)
655 return 0444;
656
657 break;
658 default:
659 break;
660 }
661 break;
662 case hwmon_fan:
663 if (data->disallow_fan_support)
664 break;
665
666 switch (attr) {
667 case hwmon_fan_input:
668 if (data->fan[channel])
669 return 0444;
670
671 break;
672 case hwmon_fan_label:
673 if (data->fan[channel] && !data->disallow_fan_type_call)
674 return 0444;
675
676 break;
677 default:
678 break;
679 }
680 break;
681 case hwmon_pwm:
682 if (data->disallow_fan_support)
683 break;
684
685 switch (attr) {
686 case hwmon_pwm_input:
687 if (data->fan[channel])
688 return 0644;
689
690 break;
691 case hwmon_pwm_enable:
692 if (data->auto_fan)
693 /*
694 * There is no command for retrieve the current status
695 * from BIOS, and userspace/firmware itself can change
696 * it.
697 * Thus we can only provide write-only access for now.
698 */
699 return 0200;
700
701 break;
702 default:
703 break;
704 }
705 break;
706 default:
707 break;
708 }
709
710 return 0;
711 }
712
dell_smm_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)713 static int dell_smm_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
714 long *val)
715 {
716 struct dell_smm_data *data = dev_get_drvdata(dev);
717 int ret;
718
719 switch (type) {
720 case hwmon_temp:
721 switch (attr) {
722 case hwmon_temp_input:
723 ret = i8k_get_temp(channel);
724 if (ret < 0)
725 return ret;
726
727 *val = ret * 1000;
728
729 return 0;
730 default:
731 break;
732 }
733 break;
734 case hwmon_fan:
735 switch (attr) {
736 case hwmon_fan_input:
737 ret = i8k_get_fan_speed(data, channel);
738 if (ret < 0)
739 return ret;
740
741 *val = ret;
742
743 return 0;
744 default:
745 break;
746 }
747 break;
748 case hwmon_pwm:
749 switch (attr) {
750 case hwmon_pwm_input:
751 ret = i8k_get_fan_status(data, channel);
752 if (ret < 0)
753 return ret;
754
755 *val = clamp_val(ret * data->i8k_pwm_mult, 0, 255);
756
757 return 0;
758 default:
759 break;
760 }
761 break;
762 default:
763 break;
764 }
765
766 return -EOPNOTSUPP;
767 }
768
dell_smm_fan_label(struct dell_smm_data * data,int channel)769 static const char *dell_smm_fan_label(struct dell_smm_data *data, int channel)
770 {
771 bool dock = false;
772 int type = i8k_get_fan_type(data, channel);
773
774 if (type < 0)
775 return ERR_PTR(type);
776
777 if (type & 0x10) {
778 dock = true;
779 type &= 0x0F;
780 }
781
782 if (type >= ARRAY_SIZE(fan_labels))
783 type = ARRAY_SIZE(fan_labels) - 1;
784
785 return dock ? docking_labels[type] : fan_labels[type];
786 }
787
dell_smm_read_string(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,const char ** str)788 static int dell_smm_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
789 int channel, const char **str)
790 {
791 struct dell_smm_data *data = dev_get_drvdata(dev);
792
793 switch (type) {
794 case hwmon_temp:
795 switch (attr) {
796 case hwmon_temp_label:
797 *str = temp_labels[data->temp_type[channel]];
798 return 0;
799 default:
800 break;
801 }
802 break;
803 case hwmon_fan:
804 switch (attr) {
805 case hwmon_fan_label:
806 *str = dell_smm_fan_label(data, channel);
807 return PTR_ERR_OR_ZERO(*str);
808 default:
809 break;
810 }
811 break;
812 default:
813 break;
814 }
815
816 return -EOPNOTSUPP;
817 }
818
dell_smm_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)819 static int dell_smm_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
820 long val)
821 {
822 struct dell_smm_data *data = dev_get_drvdata(dev);
823 unsigned long pwm;
824 bool enable;
825 int err;
826
827 switch (type) {
828 case hwmon_pwm:
829 switch (attr) {
830 case hwmon_pwm_input:
831 pwm = clamp_val(DIV_ROUND_CLOSEST(val, data->i8k_pwm_mult), 0,
832 data->i8k_fan_max);
833
834 mutex_lock(&data->i8k_mutex);
835 err = i8k_set_fan(data, channel, pwm);
836 mutex_unlock(&data->i8k_mutex);
837
838 if (err < 0)
839 return err;
840
841 return 0;
842 case hwmon_pwm_enable:
843 if (!val)
844 return -EINVAL;
845
846 if (val == 1)
847 enable = false;
848 else
849 enable = true;
850
851 mutex_lock(&data->i8k_mutex);
852 err = i8k_enable_fan_auto_mode(data, enable);
853 mutex_unlock(&data->i8k_mutex);
854
855 if (err < 0)
856 return err;
857
858 return 0;
859 default:
860 break;
861 }
862 break;
863 default:
864 break;
865 }
866
867 return -EOPNOTSUPP;
868 }
869
870 static const struct hwmon_ops dell_smm_ops = {
871 .is_visible = dell_smm_is_visible,
872 .read = dell_smm_read,
873 .read_string = dell_smm_read_string,
874 .write = dell_smm_write,
875 };
876
877 static const struct hwmon_channel_info *dell_smm_info[] = {
878 HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
879 HWMON_CHANNEL_INFO(temp,
880 HWMON_T_INPUT | HWMON_T_LABEL,
881 HWMON_T_INPUT | HWMON_T_LABEL,
882 HWMON_T_INPUT | HWMON_T_LABEL,
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 ),
891 HWMON_CHANNEL_INFO(fan,
892 HWMON_F_INPUT | HWMON_F_LABEL,
893 HWMON_F_INPUT | HWMON_F_LABEL,
894 HWMON_F_INPUT | HWMON_F_LABEL
895 ),
896 HWMON_CHANNEL_INFO(pwm,
897 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
898 HWMON_PWM_INPUT,
899 HWMON_PWM_INPUT
900 ),
901 NULL
902 };
903
904 static const struct hwmon_chip_info dell_smm_chip_info = {
905 .ops = &dell_smm_ops,
906 .info = dell_smm_info,
907 };
908
dell_smm_init_hwmon(struct device * dev)909 static int __init dell_smm_init_hwmon(struct device *dev)
910 {
911 struct dell_smm_data *data = dev_get_drvdata(dev);
912 struct device *dell_smm_hwmon_dev;
913 int i, err;
914
915 for (i = 0; i < DELL_SMM_NO_TEMP; i++) {
916 data->temp_type[i] = i8k_get_temp_type(i);
917 if (data->temp_type[i] < 0)
918 continue;
919
920 if (data->temp_type[i] >= ARRAY_SIZE(temp_labels))
921 data->temp_type[i] = ARRAY_SIZE(temp_labels) - 1;
922 }
923
924 for (i = 0; i < DELL_SMM_NO_FANS; i++) {
925 data->fan_type[i] = INT_MIN;
926 err = i8k_get_fan_status(data, i);
927 if (err < 0)
928 err = i8k_get_fan_type(data, i);
929 if (err >= 0)
930 data->fan[i] = true;
931 }
932
933 dell_smm_hwmon_dev = devm_hwmon_device_register_with_info(dev, "dell_smm", data,
934 &dell_smm_chip_info, NULL);
935
936 return PTR_ERR_OR_ZERO(dell_smm_hwmon_dev);
937 }
938
939 struct i8k_config_data {
940 uint fan_mult;
941 uint fan_max;
942 };
943
944 enum i8k_configs {
945 DELL_LATITUDE_D520,
946 DELL_PRECISION_490,
947 DELL_STUDIO,
948 DELL_XPS,
949 };
950
951 static const struct i8k_config_data i8k_config_data[] __initconst = {
952 [DELL_LATITUDE_D520] = {
953 .fan_mult = 1,
954 .fan_max = I8K_FAN_TURBO,
955 },
956 [DELL_PRECISION_490] = {
957 .fan_mult = 1,
958 .fan_max = I8K_FAN_TURBO,
959 },
960 [DELL_STUDIO] = {
961 .fan_mult = 1,
962 .fan_max = I8K_FAN_HIGH,
963 },
964 [DELL_XPS] = {
965 .fan_mult = 1,
966 .fan_max = I8K_FAN_HIGH,
967 },
968 };
969
970 static const struct dmi_system_id i8k_dmi_table[] __initconst = {
971 {
972 .ident = "Dell Inspiron",
973 .matches = {
974 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
975 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
976 },
977 },
978 {
979 .ident = "Dell Latitude",
980 .matches = {
981 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
982 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
983 },
984 },
985 {
986 .ident = "Dell Inspiron 2",
987 .matches = {
988 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
989 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
990 },
991 },
992 {
993 .ident = "Dell Latitude D520",
994 .matches = {
995 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
996 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
997 },
998 .driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
999 },
1000 {
1001 .ident = "Dell Latitude 2",
1002 .matches = {
1003 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1004 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
1005 },
1006 },
1007 { /* UK Inspiron 6400 */
1008 .ident = "Dell Inspiron 3",
1009 .matches = {
1010 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1011 DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
1012 },
1013 },
1014 {
1015 .ident = "Dell Inspiron 3",
1016 .matches = {
1017 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1018 DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
1019 },
1020 },
1021 {
1022 .ident = "Dell Precision 490",
1023 .matches = {
1024 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1025 DMI_MATCH(DMI_PRODUCT_NAME,
1026 "Precision WorkStation 490"),
1027 },
1028 .driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
1029 },
1030 {
1031 .ident = "Dell Precision",
1032 .matches = {
1033 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1034 DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
1035 },
1036 },
1037 {
1038 .ident = "Dell Vostro",
1039 .matches = {
1040 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1041 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
1042 },
1043 },
1044 {
1045 .ident = "Dell Studio",
1046 .matches = {
1047 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1048 DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
1049 },
1050 .driver_data = (void *)&i8k_config_data[DELL_STUDIO],
1051 },
1052 {
1053 .ident = "Dell XPS M140",
1054 .matches = {
1055 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1056 DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
1057 },
1058 .driver_data = (void *)&i8k_config_data[DELL_XPS],
1059 },
1060 {
1061 .ident = "Dell XPS",
1062 .matches = {
1063 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1064 DMI_MATCH(DMI_PRODUCT_NAME, "XPS"),
1065 },
1066 },
1067 { }
1068 };
1069
1070 MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
1071
1072 /*
1073 * On some machines once I8K_SMM_GET_FAN_TYPE is issued then CPU fan speed
1074 * randomly going up and down due to bug in Dell SMM or BIOS. Here is blacklist
1075 * of affected Dell machines for which we disallow I8K_SMM_GET_FAN_TYPE call.
1076 * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=100121
1077 */
1078 static const struct dmi_system_id i8k_blacklist_fan_type_dmi_table[] __initconst = {
1079 {
1080 .ident = "Dell Studio XPS 8000",
1081 .matches = {
1082 DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1083 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8000"),
1084 },
1085 },
1086 {
1087 .ident = "Dell Studio XPS 8100",
1088 .matches = {
1089 DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1090 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8100"),
1091 },
1092 },
1093 {
1094 .ident = "Dell Inspiron 580",
1095 .matches = {
1096 DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1097 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 580 "),
1098 },
1099 },
1100 { }
1101 };
1102
1103 /*
1104 * On some machines all fan related SMM functions implemented by Dell BIOS
1105 * firmware freeze kernel for about 500ms. Until Dell fixes these problems fan
1106 * support for affected blacklisted Dell machines stay disabled.
1107 * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=195751
1108 */
1109 static const struct dmi_system_id i8k_blacklist_fan_support_dmi_table[] __initconst = {
1110 {
1111 .ident = "Dell Inspiron 7720",
1112 .matches = {
1113 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1114 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 7720"),
1115 },
1116 },
1117 {
1118 .ident = "Dell Vostro 3360",
1119 .matches = {
1120 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1121 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Vostro 3360"),
1122 },
1123 },
1124 {
1125 .ident = "Dell XPS13 9333",
1126 .matches = {
1127 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1128 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS13 9333"),
1129 },
1130 },
1131 {
1132 .ident = "Dell XPS 15 L502X",
1133 .matches = {
1134 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1135 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L502X"),
1136 },
1137 },
1138 { }
1139 };
1140
1141 struct i8k_fan_control_data {
1142 unsigned int manual_fan;
1143 unsigned int auto_fan;
1144 };
1145
1146 enum i8k_fan_controls {
1147 I8K_FAN_34A3_35A3,
1148 };
1149
1150 static const struct i8k_fan_control_data i8k_fan_control_data[] __initconst = {
1151 [I8K_FAN_34A3_35A3] = {
1152 .manual_fan = 0x34a3,
1153 .auto_fan = 0x35a3,
1154 },
1155 };
1156
1157 static const struct dmi_system_id i8k_whitelist_fan_control[] __initconst = {
1158 {
1159 .ident = "Dell Latitude 5480",
1160 .matches = {
1161 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1162 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude 5480"),
1163 },
1164 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1165 },
1166 {
1167 .ident = "Dell Latitude E6440",
1168 .matches = {
1169 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1170 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E6440"),
1171 },
1172 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1173 },
1174 {
1175 .ident = "Dell Latitude E7440",
1176 .matches = {
1177 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1178 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E7440"),
1179 },
1180 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1181 },
1182 {
1183 .ident = "Dell Precision 5530",
1184 .matches = {
1185 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1186 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 5530"),
1187 },
1188 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1189 },
1190 {
1191 .ident = "Dell Precision 7510",
1192 .matches = {
1193 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1194 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
1195 },
1196 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1197 },
1198 { }
1199 };
1200
dell_smm_probe(struct platform_device * pdev)1201 static int __init dell_smm_probe(struct platform_device *pdev)
1202 {
1203 struct dell_smm_data *data;
1204 const struct dmi_system_id *id, *fan_control;
1205 int fan, ret;
1206
1207 data = devm_kzalloc(&pdev->dev, sizeof(struct dell_smm_data), GFP_KERNEL);
1208 if (!data)
1209 return -ENOMEM;
1210
1211 mutex_init(&data->i8k_mutex);
1212 data->i8k_fan_mult = I8K_FAN_MULT;
1213 data->i8k_fan_max = I8K_FAN_HIGH;
1214 platform_set_drvdata(pdev, data);
1215
1216 if (dmi_check_system(i8k_blacklist_fan_support_dmi_table)) {
1217 dev_warn(&pdev->dev, "broken Dell BIOS detected, disallow fan support\n");
1218 if (!force)
1219 data->disallow_fan_support = true;
1220 }
1221
1222 if (dmi_check_system(i8k_blacklist_fan_type_dmi_table)) {
1223 dev_warn(&pdev->dev, "broken Dell BIOS detected, disallow fan type call\n");
1224 if (!force)
1225 data->disallow_fan_type_call = true;
1226 }
1227
1228 strscpy(data->bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
1229 sizeof(data->bios_version));
1230 strscpy(data->bios_machineid, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
1231 sizeof(data->bios_machineid));
1232
1233 /*
1234 * Set fan multiplier and maximal fan speed from dmi config
1235 * Values specified in module parameters override values from dmi
1236 */
1237 id = dmi_first_match(i8k_dmi_table);
1238 if (id && id->driver_data) {
1239 const struct i8k_config_data *conf = id->driver_data;
1240
1241 if (!fan_mult && conf->fan_mult)
1242 fan_mult = conf->fan_mult;
1243
1244 if (!fan_max && conf->fan_max)
1245 fan_max = conf->fan_max;
1246 }
1247
1248 data->i8k_fan_max = fan_max ? : I8K_FAN_HIGH; /* Must not be 0 */
1249 data->i8k_pwm_mult = DIV_ROUND_UP(255, data->i8k_fan_max);
1250
1251 fan_control = dmi_first_match(i8k_whitelist_fan_control);
1252 if (fan_control && fan_control->driver_data) {
1253 const struct i8k_fan_control_data *control = fan_control->driver_data;
1254
1255 data->manual_fan = control->manual_fan;
1256 data->auto_fan = control->auto_fan;
1257 dev_info(&pdev->dev, "enabling support for setting automatic/manual fan control\n");
1258 }
1259
1260 if (!fan_mult) {
1261 /*
1262 * Autodetect fan multiplier based on nominal rpm
1263 * If fan reports rpm value too high then set multiplier to 1
1264 */
1265 for (fan = 0; fan < DELL_SMM_NO_FANS; ++fan) {
1266 ret = i8k_get_fan_nominal_speed(data, fan, data->i8k_fan_max);
1267 if (ret < 0)
1268 continue;
1269
1270 if (ret > I8K_FAN_MAX_RPM)
1271 data->i8k_fan_mult = 1;
1272 break;
1273 }
1274 } else {
1275 /* Fan multiplier was specified in module param or in dmi */
1276 data->i8k_fan_mult = fan_mult;
1277 }
1278
1279 ret = dell_smm_init_hwmon(&pdev->dev);
1280 if (ret)
1281 return ret;
1282
1283 i8k_init_procfs(&pdev->dev);
1284
1285 return 0;
1286 }
1287
1288 static struct platform_driver dell_smm_driver = {
1289 .driver = {
1290 .name = KBUILD_MODNAME,
1291 },
1292 };
1293
1294 static struct platform_device *dell_smm_device;
1295
1296 /*
1297 * Probe for the presence of a supported laptop.
1298 */
i8k_init(void)1299 static int __init i8k_init(void)
1300 {
1301 /*
1302 * Get DMI information
1303 */
1304 if (!dmi_check_system(i8k_dmi_table)) {
1305 if (!ignore_dmi && !force)
1306 return -ENODEV;
1307
1308 pr_info("not running on a supported Dell system.\n");
1309 pr_info("vendor=%s, model=%s, version=%s\n",
1310 i8k_get_dmi_data(DMI_SYS_VENDOR),
1311 i8k_get_dmi_data(DMI_PRODUCT_NAME),
1312 i8k_get_dmi_data(DMI_BIOS_VERSION));
1313 }
1314
1315 /*
1316 * Get SMM Dell signature
1317 */
1318 if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
1319 i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
1320 pr_err("unable to get SMM Dell signature\n");
1321 if (!force)
1322 return -ENODEV;
1323 }
1324
1325 dell_smm_device = platform_create_bundle(&dell_smm_driver, dell_smm_probe, NULL, 0, NULL,
1326 0);
1327
1328 return PTR_ERR_OR_ZERO(dell_smm_device);
1329 }
1330
i8k_exit(void)1331 static void __exit i8k_exit(void)
1332 {
1333 platform_device_unregister(dell_smm_device);
1334 platform_driver_unregister(&dell_smm_driver);
1335 }
1336
1337 module_init(i8k_init);
1338 module_exit(i8k_exit);
1339
