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/acpi.h>
16#include <linux/capability.h>
17#include <linux/cpu.h>
18#include <linux/ctype.h>
19#include <linux/delay.h>
20#include <linux/dmi.h>
21#include <linux/err.h>
22#include <linux/errno.h>
23#include <linux/hwmon.h>
24#include <linux/init.h>
25#include <linux/kconfig.h>
26#include <linux/kernel.h>
27#include <linux/module.h>
28#include <linux/mutex.h>
29#include <linux/platform_device.h>
30#include <linux/proc_fs.h>
31#include <linux/seq_file.h>
32#include <linux/slab.h>
33#include <linux/smp.h>
34#include <linux/string.h>
35#include <linux/thermal.h>
36#include <linux/types.h>
37#include <linux/uaccess.h>
38#include <linux/wmi.h>
39
40#include <linux/i8k.h>
41#include <asm/unaligned.h>
42
43#define I8K_SMM_FN_STATUS 0x0025
44#define I8K_SMM_POWER_STATUS 0x0069
45#define I8K_SMM_SET_FAN 0x01a3
46#define I8K_SMM_GET_FAN 0x00a3
47#define I8K_SMM_GET_SPEED 0x02a3
48#define I8K_SMM_GET_FAN_TYPE 0x03a3
49#define I8K_SMM_GET_NOM_SPEED 0x04a3
50#define I8K_SMM_GET_TEMP 0x10a3
51#define I8K_SMM_GET_TEMP_TYPE 0x11a3
52#define I8K_SMM_GET_DELL_SIG1 0xfea3
53#define I8K_SMM_GET_DELL_SIG2 0xffa3
54
55/* in usecs */
56#define DELL_SMM_MAX_DURATION 250000
57
58#define I8K_FAN_MULT 30
59#define I8K_FAN_RPM_THRESHOLD 1000
60#define I8K_MAX_TEMP 127
61
62#define I8K_FN_NONE 0x00
63#define I8K_FN_UP 0x01
64#define I8K_FN_DOWN 0x02
65#define I8K_FN_MUTE 0x04
66#define I8K_FN_MASK 0x07
67#define I8K_FN_SHIFT 8
68
69#define I8K_POWER_AC 0x05
70#define I8K_POWER_BATTERY 0x01
71
72#define DELL_SMM_WMI_GUID "F1DDEE52-063C-4784-A11E-8A06684B9B01"
73#define DELL_SMM_LEGACY_EXECUTE 0x1
74
75#define DELL_SMM_NO_TEMP 10
76#define DELL_SMM_NO_FANS 3
77
78struct smm_regs {
79 unsigned int eax;
80 unsigned int ebx;
81 unsigned int ecx;
82 unsigned int edx;
83 unsigned int esi;
84 unsigned int edi;
85};
86
87struct dell_smm_ops {
88 struct device *smm_dev;
89 int (*smm_call)(struct device *smm_dev, struct smm_regs *regs);
90};
91
92struct dell_smm_data {
93 struct mutex i8k_mutex; /* lock for sensors writes */
94 char bios_version[4];
95 char bios_machineid[16];
96 uint i8k_fan_mult;
97 uint i8k_pwm_mult;
98 uint i8k_fan_max;
99 int temp_type[DELL_SMM_NO_TEMP];
100 bool fan[DELL_SMM_NO_FANS];
101 int fan_type[DELL_SMM_NO_FANS];
102 int *fan_nominal_speed[DELL_SMM_NO_FANS];
103 const struct dell_smm_ops *ops;
104};
105
106struct dell_smm_cooling_data {
107 u8 fan_num;
108 struct dell_smm_data *data;
109};
110
111MODULE_AUTHOR("Massimo Dal Zotto <dz@debian.org>");
112MODULE_AUTHOR("Pali Rohár <pali@kernel.org>");
113MODULE_DESCRIPTION("Dell laptop SMM BIOS hwmon driver");
114MODULE_LICENSE("GPL");
115MODULE_ALIAS("i8k");
116
117static bool force;
118module_param_unsafe(force, bool, 0);
119MODULE_PARM_DESC(force, "Force loading without checking for supported models and features");
120
121static bool ignore_dmi;
122module_param(ignore_dmi, bool, 0);
123MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
124
125#if IS_ENABLED(CONFIG_I8K)
126static bool restricted = true;
127module_param(restricted, bool, 0);
128MODULE_PARM_DESC(restricted, "Restrict fan control and serial number to CAP_SYS_ADMIN (default: 1)");
129
130static bool power_status;
131module_param(power_status, bool, 0600);
132MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k (default: 0)");
133#endif
134
135static uint fan_mult;
136module_param(fan_mult, uint, 0);
137MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with (default: autodetect)");
138
139static uint fan_max;
140module_param(fan_max, uint, 0);
141MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autodetect)");
142
143static bool disallow_fan_type_call, disallow_fan_support;
144
145static unsigned int manual_fan, auto_fan;
146
147static const char * const temp_labels[] = {
148 "CPU",
149 "GPU",
150 "SODIMM",
151 "Other",
152 "Ambient",
153 "Other",
154};
155
156static const char * const fan_labels[] = {
157 "Processor Fan",
158 "Motherboard Fan",
159 "Video Fan",
160 "Power Supply Fan",
161 "Chipset Fan",
162 "Other Fan",
163};
164
165static const char * const docking_labels[] = {
166 "Docking Processor Fan",
167 "Docking Motherboard Fan",
168 "Docking Video Fan",
169 "Docking Power Supply Fan",
170 "Docking Chipset Fan",
171 "Docking Other Fan",
172};
173
174static inline const char __init *i8k_get_dmi_data(int field)
175{
176 const char *dmi_data = dmi_get_system_info(field);
177
178 return dmi_data && *dmi_data ? dmi_data : "?";
179}
180
181/*
182 * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
183 */
184static int i8k_smm_func(void *par)
185{
186 struct smm_regs *regs = par;
187 unsigned char carry;
188
189 /* SMM requires CPU 0 */
190 if (smp_processor_id() != 0)
191 return -EBUSY;
192
193 asm volatile("out %%al,$0xb2\n\t"
194 "out %%al,$0x84\n\t"
195 "setc %0\n"
196 : "=mr" (carry),
197 "+a" (regs->eax),
198 "+b" (regs->ebx),
199 "+c" (regs->ecx),
200 "+d" (regs->edx),
201 "+S" (regs->esi),
202 "+D" (regs->edi));
203
204 if (carry)
205 return -EINVAL;
206
207 return 0;
208}
209
210/*
211 * Call the System Management Mode BIOS.
212 */
213static int i8k_smm_call(struct device *dummy, struct smm_regs *regs)
214{
215 int ret;
216
217 cpus_read_lock();
218 ret = smp_call_on_cpu(cpu: 0, func: i8k_smm_func, par: regs, phys: true);
219 cpus_read_unlock();
220
221 return ret;
222}
223
224static const struct dell_smm_ops i8k_smm_ops = {
225 .smm_call = i8k_smm_call,
226};
227
228/*
229 * Call the System Management Mode BIOS over WMI.
230 */
231static ssize_t wmi_parse_register(u8 *buffer, u32 length, unsigned int *reg)
232{
233 __le32 value;
234 u32 reg_size;
235
236 if (length <= sizeof(reg_size))
237 return -ENODATA;
238
239 reg_size = get_unaligned_le32(p: buffer);
240 if (!reg_size || reg_size > sizeof(value))
241 return -ENOMSG;
242
243 if (length < sizeof(reg_size) + reg_size)
244 return -ENODATA;
245
246 memcpy_and_pad(dest: &value, dest_len: sizeof(value), src: buffer + sizeof(reg_size), count: reg_size, pad: 0);
247 *reg = le32_to_cpu(value);
248
249 return reg_size + sizeof(reg_size);
250}
251
252static int wmi_parse_response(u8 *buffer, u32 length, struct smm_regs *regs)
253{
254 unsigned int *registers[] = {
255 &regs->eax,
256 &regs->ebx,
257 &regs->ecx,
258 &regs->edx
259 };
260 u32 offset = 0;
261 ssize_t ret;
262 int i;
263
264 for (i = 0; i < ARRAY_SIZE(registers); i++) {
265 if (offset >= length)
266 return -ENODATA;
267
268 ret = wmi_parse_register(buffer: buffer + offset, length: length - offset, reg: registers[i]);
269 if (ret < 0)
270 return ret;
271
272 offset += ret;
273 }
274
275 if (offset != length)
276 return -ENOMSG;
277
278 return 0;
279}
280
281static int wmi_smm_call(struct device *dev, struct smm_regs *regs)
282{
283 struct wmi_device *wdev = container_of(dev, struct wmi_device, dev);
284 struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
285 u32 wmi_payload[] = {
286 sizeof(regs->eax),
287 regs->eax,
288 sizeof(regs->ebx),
289 regs->ebx,
290 sizeof(regs->ecx),
291 regs->ecx,
292 sizeof(regs->edx),
293 regs->edx
294 };
295 const struct acpi_buffer in = {
296 .length = sizeof(wmi_payload),
297 .pointer = &wmi_payload,
298 };
299 union acpi_object *obj;
300 acpi_status status;
301 int ret;
302
303 status = wmidev_evaluate_method(wdev, instance: 0x0, DELL_SMM_LEGACY_EXECUTE, in: &in, out: &out);
304 if (ACPI_FAILURE(status))
305 return -EIO;
306
307 obj = out.pointer;
308 if (!obj)
309 return -ENODATA;
310
311 if (obj->type != ACPI_TYPE_BUFFER) {
312 ret = -ENOMSG;
313
314 goto err_free;
315 }
316
317 ret = wmi_parse_response(buffer: obj->buffer.pointer, length: obj->buffer.length, regs);
318
319err_free:
320 kfree(objp: obj);
321
322 return ret;
323}
324
325static int dell_smm_call(const struct dell_smm_ops *ops, struct smm_regs *regs)
326{
327 unsigned int eax = regs->eax;
328 unsigned int ebx = regs->ebx;
329 long long duration;
330 ktime_t calltime;
331 int ret;
332
333 calltime = ktime_get();
334 ret = ops->smm_call(ops->smm_dev, regs);
335 duration = ktime_us_delta(later: ktime_get(), earlier: calltime);
336
337 pr_debug("SMM(0x%.4x 0x%.4x) = 0x%.4x status: %d (took %7lld usecs)\n",
338 eax, ebx, regs->eax & 0xffff, ret, duration);
339
340 if (duration > DELL_SMM_MAX_DURATION)
341 pr_warn_once("SMM call took %lld usecs!\n", duration);
342
343 if (ret < 0)
344 return ret;
345
346 if ((regs->eax & 0xffff) == 0xffff || regs->eax == eax)
347 return -EINVAL;
348
349 return 0;
350}
351
352/*
353 * Read the fan status.
354 */
355static int i8k_get_fan_status(const struct dell_smm_data *data, u8 fan)
356{
357 struct smm_regs regs = {
358 .eax = I8K_SMM_GET_FAN,
359 .ebx = fan,
360 };
361
362 if (disallow_fan_support)
363 return -EINVAL;
364
365 return dell_smm_call(ops: data->ops, regs: &regs) ? : regs.eax & 0xff;
366}
367
368/*
369 * Read the fan speed in RPM.
370 */
371static int i8k_get_fan_speed(const struct dell_smm_data *data, u8 fan)
372{
373 struct smm_regs regs = {
374 .eax = I8K_SMM_GET_SPEED,
375 .ebx = fan,
376 };
377
378 if (disallow_fan_support)
379 return -EINVAL;
380
381 return dell_smm_call(ops: data->ops, regs: &regs) ? : (regs.eax & 0xffff) * data->i8k_fan_mult;
382}
383
384/*
385 * Read the fan type.
386 */
387static int _i8k_get_fan_type(const struct dell_smm_data *data, u8 fan)
388{
389 struct smm_regs regs = {
390 .eax = I8K_SMM_GET_FAN_TYPE,
391 .ebx = fan,
392 };
393
394 if (disallow_fan_support || disallow_fan_type_call)
395 return -EINVAL;
396
397 return dell_smm_call(ops: data->ops, regs: &regs) ? : regs.eax & 0xff;
398}
399
400static int i8k_get_fan_type(struct dell_smm_data *data, u8 fan)
401{
402 /* I8K_SMM_GET_FAN_TYPE SMM call is expensive, so cache values */
403 if (data->fan_type[fan] == INT_MIN)
404 data->fan_type[fan] = _i8k_get_fan_type(data, fan);
405
406 return data->fan_type[fan];
407}
408
409/*
410 * Read the fan nominal rpm for specific fan speed.
411 */
412static int i8k_get_fan_nominal_speed(const struct dell_smm_data *data, u8 fan, int speed)
413{
414 struct smm_regs regs = {
415 .eax = I8K_SMM_GET_NOM_SPEED,
416 .ebx = fan | (speed << 8),
417 };
418
419 if (disallow_fan_support)
420 return -EINVAL;
421
422 return dell_smm_call(ops: data->ops, regs: &regs) ? : (regs.eax & 0xffff);
423}
424
425/*
426 * Enable or disable automatic BIOS fan control support
427 */
428static int i8k_enable_fan_auto_mode(const struct dell_smm_data *data, bool enable)
429{
430 struct smm_regs regs = { };
431
432 if (disallow_fan_support)
433 return -EINVAL;
434
435 regs.eax = enable ? auto_fan : manual_fan;
436 return dell_smm_call(ops: data->ops, regs: &regs);
437}
438
439/*
440 * Set the fan speed (off, low, high, ...).
441 */
442static int i8k_set_fan(const struct dell_smm_data *data, u8 fan, int speed)
443{
444 struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
445
446 if (disallow_fan_support)
447 return -EINVAL;
448
449 speed = (speed < 0) ? 0 : ((speed > data->i8k_fan_max) ? data->i8k_fan_max : speed);
450 regs.ebx = fan | (speed << 8);
451
452 return dell_smm_call(ops: data->ops, regs: &regs);
453}
454
455static int i8k_get_temp_type(const struct dell_smm_data *data, u8 sensor)
456{
457 struct smm_regs regs = {
458 .eax = I8K_SMM_GET_TEMP_TYPE,
459 .ebx = sensor,
460 };
461
462 return dell_smm_call(ops: data->ops, regs: &regs) ? : regs.eax & 0xff;
463}
464
465/*
466 * Read the cpu temperature.
467 */
468static int _i8k_get_temp(const struct dell_smm_data *data, u8 sensor)
469{
470 struct smm_regs regs = {
471 .eax = I8K_SMM_GET_TEMP,
472 .ebx = sensor,
473 };
474
475 return dell_smm_call(ops: data->ops, regs: &regs) ? : regs.eax & 0xff;
476}
477
478static int i8k_get_temp(const struct dell_smm_data *data, u8 sensor)
479{
480 int temp = _i8k_get_temp(data, sensor);
481
482 /*
483 * Sometimes the temperature sensor returns 0x99, which is out of range.
484 * In this case we retry (once) before returning an error.
485 # 1003655137 00000058 00005a4b
486 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
487 # 1003655139 00000054 00005c52
488 */
489 if (temp == 0x99) {
490 msleep(msecs: 100);
491 temp = _i8k_get_temp(data, sensor);
492 }
493 /*
494 * Return -ENODATA for all invalid temperatures.
495 *
496 * Known instances are the 0x99 value as seen above as well as
497 * 0xc1 (193), which may be returned when trying to read the GPU
498 * temperature if the system supports a GPU and it is currently
499 * turned off.
500 */
501 if (temp > I8K_MAX_TEMP)
502 return -ENODATA;
503
504 return temp;
505}
506
507static int dell_smm_get_signature(const struct dell_smm_ops *ops, int req_fn)
508{
509 struct smm_regs regs = { .eax = req_fn, };
510 int rc;
511
512 rc = dell_smm_call(ops, regs: &regs);
513 if (rc < 0)
514 return rc;
515
516 return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
517}
518
519#if IS_ENABLED(CONFIG_I8K)
520
521/*
522 * Read the Fn key status.
523 */
524static int i8k_get_fn_status(const struct dell_smm_data *data)
525{
526 struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
527 int rc;
528
529 rc = dell_smm_call(ops: data->ops, regs: &regs);
530 if (rc < 0)
531 return rc;
532
533 switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
534 case I8K_FN_UP:
535 return I8K_VOL_UP;
536 case I8K_FN_DOWN:
537 return I8K_VOL_DOWN;
538 case I8K_FN_MUTE:
539 return I8K_VOL_MUTE;
540 default:
541 return 0;
542 }
543}
544
545/*
546 * Read the power status.
547 */
548static int i8k_get_power_status(const struct dell_smm_data *data)
549{
550 struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
551 int rc;
552
553 rc = dell_smm_call(ops: data->ops, regs: &regs);
554 if (rc < 0)
555 return rc;
556
557 return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
558}
559
560/*
561 * Procfs interface
562 */
563
564static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
565{
566 struct dell_smm_data *data = pde_data(inode: file_inode(f: fp));
567 int __user *argp = (int __user *)arg;
568 int speed, err;
569 int val = 0;
570
571 if (!argp)
572 return -EINVAL;
573
574 switch (cmd) {
575 case I8K_BIOS_VERSION:
576 if (!isdigit(c: data->bios_version[0]) || !isdigit(c: data->bios_version[1]) ||
577 !isdigit(c: data->bios_version[2]))
578 return -EINVAL;
579
580 val = (data->bios_version[0] << 16) |
581 (data->bios_version[1] << 8) | data->bios_version[2];
582
583 if (copy_to_user(to: argp, from: &val, n: sizeof(val)))
584 return -EFAULT;
585
586 return 0;
587 case I8K_MACHINE_ID:
588 if (restricted && !capable(CAP_SYS_ADMIN))
589 return -EPERM;
590
591 if (copy_to_user(to: argp, from: data->bios_machineid, n: sizeof(data->bios_machineid)))
592 return -EFAULT;
593
594 return 0;
595 case I8K_FN_STATUS:
596 val = i8k_get_fn_status(data);
597 break;
598
599 case I8K_POWER_STATUS:
600 val = i8k_get_power_status(data);
601 break;
602
603 case I8K_GET_TEMP:
604 val = i8k_get_temp(data, sensor: 0);
605 break;
606
607 case I8K_GET_SPEED:
608 if (copy_from_user(to: &val, from: argp, n: sizeof(int)))
609 return -EFAULT;
610
611 if (val > U8_MAX || val < 0)
612 return -EINVAL;
613
614 val = i8k_get_fan_speed(data, fan: val);
615 break;
616
617 case I8K_GET_FAN:
618 if (copy_from_user(to: &val, from: argp, n: sizeof(int)))
619 return -EFAULT;
620
621 if (val > U8_MAX || val < 0)
622 return -EINVAL;
623
624 val = i8k_get_fan_status(data, fan: val);
625 break;
626
627 case I8K_SET_FAN:
628 if (restricted && !capable(CAP_SYS_ADMIN))
629 return -EPERM;
630
631 if (copy_from_user(to: &val, from: argp, n: sizeof(int)))
632 return -EFAULT;
633
634 if (val > U8_MAX || val < 0)
635 return -EINVAL;
636
637 if (copy_from_user(to: &speed, from: argp + 1, n: sizeof(int)))
638 return -EFAULT;
639
640 mutex_lock(&data->i8k_mutex);
641 err = i8k_set_fan(data, fan: val, speed);
642 if (err < 0)
643 val = err;
644 else
645 val = i8k_get_fan_status(data, fan: val);
646 mutex_unlock(lock: &data->i8k_mutex);
647 break;
648
649 default:
650 return -ENOIOCTLCMD;
651 }
652
653 if (val < 0)
654 return val;
655
656 if (copy_to_user(to: argp, from: &val, n: sizeof(int)))
657 return -EFAULT;
658
659 return 0;
660}
661
662/*
663 * Print the information for /proc/i8k.
664 */
665static int i8k_proc_show(struct seq_file *seq, void *offset)
666{
667 struct dell_smm_data *data = seq->private;
668 int fn_key, cpu_temp, ac_power;
669 int left_fan, right_fan, left_speed, right_speed;
670
671 cpu_temp = i8k_get_temp(data, sensor: 0); /* 11100 µs */
672 left_fan = i8k_get_fan_status(data, I8K_FAN_LEFT); /* 580 µs */
673 right_fan = i8k_get_fan_status(data, I8K_FAN_RIGHT); /* 580 µs */
674 left_speed = i8k_get_fan_speed(data, I8K_FAN_LEFT); /* 580 µs */
675 right_speed = i8k_get_fan_speed(data, I8K_FAN_RIGHT); /* 580 µs */
676 fn_key = i8k_get_fn_status(data); /* 750 µs */
677 if (power_status)
678 ac_power = i8k_get_power_status(data); /* 14700 µs */
679 else
680 ac_power = -1;
681
682 /*
683 * Info:
684 *
685 * 1) Format version (this will change if format changes)
686 * 2) BIOS version
687 * 3) BIOS machine ID
688 * 4) Cpu temperature
689 * 5) Left fan status
690 * 6) Right fan status
691 * 7) Left fan speed
692 * 8) Right fan speed
693 * 9) AC power
694 * 10) Fn Key status
695 */
696 seq_printf(m: seq, fmt: "%s %s %s %d %d %d %d %d %d %d\n",
697 I8K_PROC_FMT,
698 data->bios_version,
699 (restricted && !capable(CAP_SYS_ADMIN)) ? "-1" : data->bios_machineid,
700 cpu_temp,
701 left_fan, right_fan, left_speed, right_speed,
702 ac_power, fn_key);
703
704 return 0;
705}
706
707static int i8k_open_fs(struct inode *inode, struct file *file)
708{
709 return single_open(file, i8k_proc_show, pde_data(inode));
710}
711
712static const struct proc_ops i8k_proc_ops = {
713 .proc_open = i8k_open_fs,
714 .proc_read = seq_read,
715 .proc_lseek = seq_lseek,
716 .proc_release = single_release,
717 .proc_ioctl = i8k_ioctl,
718};
719
720static void i8k_exit_procfs(void *param)
721{
722 remove_proc_entry("i8k", NULL);
723}
724
725static void __init i8k_init_procfs(struct device *dev)
726{
727 struct dell_smm_data *data = dev_get_drvdata(dev);
728
729 strscpy(data->bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
730 sizeof(data->bios_version));
731 strscpy(data->bios_machineid, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
732 sizeof(data->bios_machineid));
733
734 /* Only register exit function if creation was successful */
735 if (proc_create_data("i8k", 0, NULL, &i8k_proc_ops, data))
736 devm_add_action_or_reset(dev, i8k_exit_procfs, NULL);
737}
738
739#else
740
741static void __init i8k_init_procfs(struct device *dev)
742{
743}
744
745#endif
746
747static int dell_smm_get_max_state(struct thermal_cooling_device *dev, unsigned long *state)
748{
749 struct dell_smm_cooling_data *cdata = dev->devdata;
750
751 *state = cdata->data->i8k_fan_max;
752
753 return 0;
754}
755
756static int dell_smm_get_cur_state(struct thermal_cooling_device *dev, unsigned long *state)
757{
758 struct dell_smm_cooling_data *cdata = dev->devdata;
759 int ret;
760
761 ret = i8k_get_fan_status(data: cdata->data, fan: cdata->fan_num);
762 if (ret < 0)
763 return ret;
764
765 *state = ret;
766
767 return 0;
768}
769
770static int dell_smm_set_cur_state(struct thermal_cooling_device *dev, unsigned long state)
771{
772 struct dell_smm_cooling_data *cdata = dev->devdata;
773 struct dell_smm_data *data = cdata->data;
774 int ret;
775
776 if (state > data->i8k_fan_max)
777 return -EINVAL;
778
779 mutex_lock(&data->i8k_mutex);
780 ret = i8k_set_fan(data, fan: cdata->fan_num, speed: (int)state);
781 mutex_unlock(lock: &data->i8k_mutex);
782
783 return ret;
784}
785
786static const struct thermal_cooling_device_ops dell_smm_cooling_ops = {
787 .get_max_state = dell_smm_get_max_state,
788 .get_cur_state = dell_smm_get_cur_state,
789 .set_cur_state = dell_smm_set_cur_state,
790};
791
792static umode_t dell_smm_is_visible(const void *drvdata, enum hwmon_sensor_types type, u32 attr,
793 int channel)
794{
795 const struct dell_smm_data *data = drvdata;
796
797 switch (type) {
798 case hwmon_temp:
799 switch (attr) {
800 case hwmon_temp_input:
801 /* _i8k_get_temp() is fine since we do not care about the actual value */
802 if (data->temp_type[channel] >= 0 || _i8k_get_temp(data, sensor: channel) >= 0)
803 return 0444;
804
805 break;
806 case hwmon_temp_label:
807 if (data->temp_type[channel] >= 0)
808 return 0444;
809
810 break;
811 default:
812 break;
813 }
814 break;
815 case hwmon_fan:
816 if (disallow_fan_support)
817 break;
818
819 switch (attr) {
820 case hwmon_fan_input:
821 if (data->fan[channel])
822 return 0444;
823
824 break;
825 case hwmon_fan_label:
826 if (data->fan[channel] && !disallow_fan_type_call)
827 return 0444;
828
829 break;
830 case hwmon_fan_min:
831 case hwmon_fan_max:
832 case hwmon_fan_target:
833 if (data->fan_nominal_speed[channel])
834 return 0444;
835
836 break;
837 default:
838 break;
839 }
840 break;
841 case hwmon_pwm:
842 if (disallow_fan_support)
843 break;
844
845 switch (attr) {
846 case hwmon_pwm_input:
847 if (data->fan[channel])
848 return 0644;
849
850 break;
851 case hwmon_pwm_enable:
852 if (auto_fan)
853 /*
854 * There is no command for retrieve the current status
855 * from BIOS, and userspace/firmware itself can change
856 * it.
857 * Thus we can only provide write-only access for now.
858 */
859 return 0200;
860
861 break;
862 default:
863 break;
864 }
865 break;
866 default:
867 break;
868 }
869
870 return 0;
871}
872
873static int dell_smm_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
874 long *val)
875{
876 struct dell_smm_data *data = dev_get_drvdata(dev);
877 int mult = data->i8k_fan_mult;
878 int ret;
879
880 switch (type) {
881 case hwmon_temp:
882 switch (attr) {
883 case hwmon_temp_input:
884 ret = i8k_get_temp(data, sensor: channel);
885 if (ret < 0)
886 return ret;
887
888 *val = ret * 1000;
889
890 return 0;
891 default:
892 break;
893 }
894 break;
895 case hwmon_fan:
896 switch (attr) {
897 case hwmon_fan_input:
898 ret = i8k_get_fan_speed(data, fan: channel);
899 if (ret < 0)
900 return ret;
901
902 *val = ret;
903
904 return 0;
905 case hwmon_fan_min:
906 *val = data->fan_nominal_speed[channel][0] * mult;
907
908 return 0;
909 case hwmon_fan_max:
910 *val = data->fan_nominal_speed[channel][data->i8k_fan_max] * mult;
911
912 return 0;
913 case hwmon_fan_target:
914 ret = i8k_get_fan_status(data, fan: channel);
915 if (ret < 0)
916 return ret;
917
918 if (ret > data->i8k_fan_max)
919 ret = data->i8k_fan_max;
920
921 *val = data->fan_nominal_speed[channel][ret] * mult;
922
923 return 0;
924 default:
925 break;
926 }
927 break;
928 case hwmon_pwm:
929 switch (attr) {
930 case hwmon_pwm_input:
931 ret = i8k_get_fan_status(data, fan: channel);
932 if (ret < 0)
933 return ret;
934
935 *val = clamp_val(ret * data->i8k_pwm_mult, 0, 255);
936
937 return 0;
938 default:
939 break;
940 }
941 break;
942 default:
943 break;
944 }
945
946 return -EOPNOTSUPP;
947}
948
949static const char *dell_smm_fan_label(struct dell_smm_data *data, int channel)
950{
951 bool dock = false;
952 int type = i8k_get_fan_type(data, fan: channel);
953
954 if (type < 0)
955 return ERR_PTR(error: type);
956
957 if (type & 0x10) {
958 dock = true;
959 type &= 0x0F;
960 }
961
962 if (type >= ARRAY_SIZE(fan_labels))
963 type = ARRAY_SIZE(fan_labels) - 1;
964
965 return dock ? docking_labels[type] : fan_labels[type];
966}
967
968static int dell_smm_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
969 int channel, const char **str)
970{
971 struct dell_smm_data *data = dev_get_drvdata(dev);
972
973 switch (type) {
974 case hwmon_temp:
975 switch (attr) {
976 case hwmon_temp_label:
977 *str = temp_labels[data->temp_type[channel]];
978 return 0;
979 default:
980 break;
981 }
982 break;
983 case hwmon_fan:
984 switch (attr) {
985 case hwmon_fan_label:
986 *str = dell_smm_fan_label(data, channel);
987 return PTR_ERR_OR_ZERO(ptr: *str);
988 default:
989 break;
990 }
991 break;
992 default:
993 break;
994 }
995
996 return -EOPNOTSUPP;
997}
998
999static int dell_smm_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
1000 long val)
1001{
1002 struct dell_smm_data *data = dev_get_drvdata(dev);
1003 unsigned long pwm;
1004 bool enable;
1005 int err;
1006
1007 switch (type) {
1008 case hwmon_pwm:
1009 switch (attr) {
1010 case hwmon_pwm_input:
1011 pwm = clamp_val(DIV_ROUND_CLOSEST(val, data->i8k_pwm_mult), 0,
1012 data->i8k_fan_max);
1013
1014 mutex_lock(&data->i8k_mutex);
1015 err = i8k_set_fan(data, fan: channel, speed: pwm);
1016 mutex_unlock(lock: &data->i8k_mutex);
1017
1018 if (err < 0)
1019 return err;
1020
1021 return 0;
1022 case hwmon_pwm_enable:
1023 if (!val)
1024 return -EINVAL;
1025
1026 if (val == 1)
1027 enable = false;
1028 else
1029 enable = true;
1030
1031 mutex_lock(&data->i8k_mutex);
1032 err = i8k_enable_fan_auto_mode(data, enable);
1033 mutex_unlock(lock: &data->i8k_mutex);
1034
1035 if (err < 0)
1036 return err;
1037
1038 return 0;
1039 default:
1040 break;
1041 }
1042 break;
1043 default:
1044 break;
1045 }
1046
1047 return -EOPNOTSUPP;
1048}
1049
1050static const struct hwmon_ops dell_smm_ops = {
1051 .is_visible = dell_smm_is_visible,
1052 .read = dell_smm_read,
1053 .read_string = dell_smm_read_string,
1054 .write = dell_smm_write,
1055};
1056
1057static const struct hwmon_channel_info * const dell_smm_info[] = {
1058 HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
1059 HWMON_CHANNEL_INFO(temp,
1060 HWMON_T_INPUT | HWMON_T_LABEL,
1061 HWMON_T_INPUT | HWMON_T_LABEL,
1062 HWMON_T_INPUT | HWMON_T_LABEL,
1063 HWMON_T_INPUT | HWMON_T_LABEL,
1064 HWMON_T_INPUT | HWMON_T_LABEL,
1065 HWMON_T_INPUT | HWMON_T_LABEL,
1066 HWMON_T_INPUT | HWMON_T_LABEL,
1067 HWMON_T_INPUT | HWMON_T_LABEL,
1068 HWMON_T_INPUT | HWMON_T_LABEL,
1069 HWMON_T_INPUT | HWMON_T_LABEL
1070 ),
1071 HWMON_CHANNEL_INFO(fan,
1072 HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
1073 HWMON_F_TARGET,
1074 HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
1075 HWMON_F_TARGET,
1076 HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
1077 HWMON_F_TARGET
1078 ),
1079 HWMON_CHANNEL_INFO(pwm,
1080 HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
1081 HWMON_PWM_INPUT,
1082 HWMON_PWM_INPUT
1083 ),
1084 NULL
1085};
1086
1087static const struct hwmon_chip_info dell_smm_chip_info = {
1088 .ops = &dell_smm_ops,
1089 .info = dell_smm_info,
1090};
1091
1092static int dell_smm_init_cdev(struct device *dev, u8 fan_num)
1093{
1094 struct dell_smm_data *data = dev_get_drvdata(dev);
1095 struct thermal_cooling_device *cdev;
1096 struct dell_smm_cooling_data *cdata;
1097 int ret = 0;
1098 char *name;
1099
1100 name = kasprintf(GFP_KERNEL, fmt: "dell-smm-fan%u", fan_num + 1);
1101 if (!name)
1102 return -ENOMEM;
1103
1104 cdata = devm_kmalloc(dev, size: sizeof(*cdata), GFP_KERNEL);
1105 if (cdata) {
1106 cdata->fan_num = fan_num;
1107 cdata->data = data;
1108 cdev = devm_thermal_of_cooling_device_register(dev, NULL, type: name, devdata: cdata,
1109 ops: &dell_smm_cooling_ops);
1110 if (IS_ERR(ptr: cdev)) {
1111 devm_kfree(dev, p: cdata);
1112 ret = PTR_ERR(ptr: cdev);
1113 }
1114 } else {
1115 ret = -ENOMEM;
1116 }
1117
1118 kfree(objp: name);
1119
1120 return ret;
1121}
1122
1123static int dell_smm_init_hwmon(struct device *dev)
1124{
1125 struct dell_smm_data *data = dev_get_drvdata(dev);
1126 struct device *dell_smm_hwmon_dev;
1127 int state, err;
1128 u8 i;
1129
1130 for (i = 0; i < DELL_SMM_NO_TEMP; i++) {
1131 data->temp_type[i] = i8k_get_temp_type(data, sensor: i);
1132 if (data->temp_type[i] < 0)
1133 continue;
1134
1135 if (data->temp_type[i] >= ARRAY_SIZE(temp_labels))
1136 data->temp_type[i] = ARRAY_SIZE(temp_labels) - 1;
1137 }
1138
1139 for (i = 0; i < DELL_SMM_NO_FANS; i++) {
1140 data->fan_type[i] = INT_MIN;
1141 err = i8k_get_fan_status(data, fan: i);
1142 if (err < 0)
1143 err = i8k_get_fan_type(data, fan: i);
1144
1145 if (err < 0)
1146 continue;
1147
1148 data->fan[i] = true;
1149
1150 /* the cooling device is not critical, ignore failures */
1151 if (IS_REACHABLE(CONFIG_THERMAL)) {
1152 err = dell_smm_init_cdev(dev, fan_num: i);
1153 if (err < 0)
1154 dev_warn(dev, "Failed to register cooling device for fan %u\n",
1155 i + 1);
1156 }
1157
1158 data->fan_nominal_speed[i] = devm_kmalloc_array(dev, n: data->i8k_fan_max + 1,
1159 size: sizeof(*data->fan_nominal_speed[i]),
1160 GFP_KERNEL);
1161 if (!data->fan_nominal_speed[i])
1162 continue;
1163
1164 for (state = 0; state <= data->i8k_fan_max; state++) {
1165 err = i8k_get_fan_nominal_speed(data, fan: i, speed: state);
1166 if (err < 0) {
1167 /* Mark nominal speed table as invalid in case of error */
1168 devm_kfree(dev, p: data->fan_nominal_speed[i]);
1169 data->fan_nominal_speed[i] = NULL;
1170 break;
1171 }
1172 data->fan_nominal_speed[i][state] = err;
1173 /*
1174 * Autodetect fan multiplier based on nominal rpm if multiplier
1175 * was not specified as module param or in DMI. If fan reports
1176 * rpm value too high then set multiplier to 1.
1177 */
1178 if (!fan_mult && err > I8K_FAN_RPM_THRESHOLD)
1179 data->i8k_fan_mult = 1;
1180 }
1181 }
1182
1183 dell_smm_hwmon_dev = devm_hwmon_device_register_with_info(dev, name: "dell_smm", drvdata: data,
1184 info: &dell_smm_chip_info, NULL);
1185
1186 return PTR_ERR_OR_ZERO(ptr: dell_smm_hwmon_dev);
1187}
1188
1189static int dell_smm_init_data(struct device *dev, const struct dell_smm_ops *ops)
1190{
1191 struct dell_smm_data *data;
1192
1193 data = devm_kzalloc(dev, size: sizeof(*data), GFP_KERNEL);
1194 if (!data)
1195 return -ENOMEM;
1196
1197 mutex_init(&data->i8k_mutex);
1198 dev_set_drvdata(dev, data);
1199
1200 data->ops = ops;
1201 /* All options must not be 0 */
1202 data->i8k_fan_mult = fan_mult ? : I8K_FAN_MULT;
1203 data->i8k_fan_max = fan_max ? : I8K_FAN_HIGH;
1204 data->i8k_pwm_mult = DIV_ROUND_UP(255, data->i8k_fan_max);
1205
1206 return 0;
1207}
1208
1209static const struct dmi_system_id i8k_dmi_table[] __initconst = {
1210 {
1211 .ident = "Dell G5 5590",
1212 .matches = {
1213 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1214 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "G5 5590"),
1215 },
1216 },
1217 {
1218 .ident = "Dell Inspiron",
1219 .matches = {
1220 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
1221 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
1222 },
1223 },
1224 {
1225 .ident = "Dell Latitude",
1226 .matches = {
1227 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
1228 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
1229 },
1230 },
1231 {
1232 .ident = "Dell Inspiron 2",
1233 .matches = {
1234 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1235 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
1236 },
1237 },
1238 {
1239 .ident = "Dell Latitude 2",
1240 .matches = {
1241 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1242 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
1243 },
1244 },
1245 { /* UK Inspiron 6400 */
1246 .ident = "Dell Inspiron 3",
1247 .matches = {
1248 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1249 DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
1250 },
1251 },
1252 {
1253 .ident = "Dell Inspiron 3",
1254 .matches = {
1255 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1256 DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
1257 },
1258 },
1259 {
1260 .ident = "Dell Precision",
1261 .matches = {
1262 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1263 DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
1264 },
1265 },
1266 {
1267 .ident = "Dell Vostro",
1268 .matches = {
1269 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1270 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
1271 },
1272 },
1273 {
1274 .ident = "Dell Studio",
1275 .matches = {
1276 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1277 DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
1278 },
1279 },
1280 {
1281 .ident = "Dell XPS M140",
1282 .matches = {
1283 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1284 DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
1285 },
1286 },
1287 {
1288 .ident = "Dell XPS",
1289 .matches = {
1290 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1291 DMI_MATCH(DMI_PRODUCT_NAME, "XPS"),
1292 },
1293 },
1294 { }
1295};
1296
1297MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
1298
1299/*
1300 * Only use for machines which need some special configuration
1301 * in order to work correctly (e.g. if autoconfig fails on this machines).
1302 */
1303struct i8k_config_data {
1304 uint fan_mult;
1305 uint fan_max;
1306};
1307
1308enum i8k_configs {
1309 DELL_LATITUDE_D520,
1310 DELL_PRECISION_490,
1311 DELL_STUDIO,
1312 DELL_XPS,
1313};
1314
1315static const struct i8k_config_data i8k_config_data[] __initconst = {
1316 [DELL_LATITUDE_D520] = {
1317 .fan_mult = 1,
1318 .fan_max = I8K_FAN_TURBO,
1319 },
1320 [DELL_PRECISION_490] = {
1321 .fan_mult = 1,
1322 .fan_max = I8K_FAN_TURBO,
1323 },
1324 [DELL_STUDIO] = {
1325 .fan_mult = 1,
1326 .fan_max = I8K_FAN_HIGH,
1327 },
1328 [DELL_XPS] = {
1329 .fan_mult = 1,
1330 .fan_max = I8K_FAN_HIGH,
1331 },
1332};
1333
1334static const struct dmi_system_id i8k_config_dmi_table[] __initconst = {
1335 {
1336 .ident = "Dell Latitude D520",
1337 .matches = {
1338 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1339 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
1340 },
1341 .driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
1342 },
1343 {
1344 .ident = "Dell Precision 490",
1345 .matches = {
1346 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1347 DMI_MATCH(DMI_PRODUCT_NAME,
1348 "Precision WorkStation 490"),
1349 },
1350 .driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
1351 },
1352 {
1353 .ident = "Dell Studio",
1354 .matches = {
1355 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1356 DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
1357 },
1358 .driver_data = (void *)&i8k_config_data[DELL_STUDIO],
1359 },
1360 {
1361 .ident = "Dell XPS M140",
1362 .matches = {
1363 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1364 DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
1365 },
1366 .driver_data = (void *)&i8k_config_data[DELL_XPS],
1367 },
1368 { }
1369};
1370
1371/*
1372 * On some machines once I8K_SMM_GET_FAN_TYPE is issued then CPU fan speed
1373 * randomly going up and down due to bug in Dell SMM or BIOS. Here is blacklist
1374 * of affected Dell machines for which we disallow I8K_SMM_GET_FAN_TYPE call.
1375 * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=100121
1376 */
1377static const struct dmi_system_id i8k_blacklist_fan_type_dmi_table[] __initconst = {
1378 {
1379 .ident = "Dell Studio XPS 8000",
1380 .matches = {
1381 DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1382 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8000"),
1383 },
1384 },
1385 {
1386 .ident = "Dell Studio XPS 8100",
1387 .matches = {
1388 DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1389 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8100"),
1390 },
1391 },
1392 {
1393 .ident = "Dell Inspiron 580",
1394 .matches = {
1395 DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1396 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 580 "),
1397 },
1398 },
1399 {
1400 .ident = "Dell Inspiron 3505",
1401 .matches = {
1402 DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1403 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 3505"),
1404 },
1405 },
1406 { }
1407};
1408
1409/*
1410 * On some machines all fan related SMM functions implemented by Dell BIOS
1411 * firmware freeze kernel for about 500ms. Until Dell fixes these problems fan
1412 * support for affected blacklisted Dell machines stay disabled.
1413 * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=195751
1414 */
1415static const struct dmi_system_id i8k_blacklist_fan_support_dmi_table[] __initconst = {
1416 {
1417 .ident = "Dell Inspiron 7720",
1418 .matches = {
1419 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1420 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 7720"),
1421 },
1422 },
1423 {
1424 .ident = "Dell Vostro 3360",
1425 .matches = {
1426 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1427 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Vostro 3360"),
1428 },
1429 },
1430 {
1431 .ident = "Dell XPS13 9333",
1432 .matches = {
1433 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1434 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS13 9333"),
1435 },
1436 },
1437 {
1438 .ident = "Dell XPS 15 L502X",
1439 .matches = {
1440 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1441 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L502X"),
1442 },
1443 },
1444 { }
1445};
1446
1447struct i8k_fan_control_data {
1448 unsigned int manual_fan;
1449 unsigned int auto_fan;
1450};
1451
1452enum i8k_fan_controls {
1453 I8K_FAN_30A3_31A3,
1454 I8K_FAN_34A3_35A3,
1455};
1456
1457static const struct i8k_fan_control_data i8k_fan_control_data[] __initconst = {
1458 [I8K_FAN_30A3_31A3] = {
1459 .manual_fan = 0x30a3,
1460 .auto_fan = 0x31a3,
1461 },
1462 [I8K_FAN_34A3_35A3] = {
1463 .manual_fan = 0x34a3,
1464 .auto_fan = 0x35a3,
1465 },
1466};
1467
1468static const struct dmi_system_id i8k_whitelist_fan_control[] __initconst = {
1469 {
1470 .ident = "Dell Latitude 5480",
1471 .matches = {
1472 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1473 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude 5480"),
1474 },
1475 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1476 },
1477 {
1478 .ident = "Dell Latitude E6440",
1479 .matches = {
1480 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1481 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E6440"),
1482 },
1483 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1484 },
1485 {
1486 .ident = "Dell Latitude E7440",
1487 .matches = {
1488 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1489 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E7440"),
1490 },
1491 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1492 },
1493 {
1494 .ident = "Dell Precision 5530",
1495 .matches = {
1496 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1497 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 5530"),
1498 },
1499 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1500 },
1501 {
1502 .ident = "Dell Precision 7510",
1503 .matches = {
1504 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1505 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
1506 },
1507 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1508 },
1509 {
1510 .ident = "Dell XPS 13 7390",
1511 .matches = {
1512 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1513 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS 13 7390"),
1514 },
1515 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1516 },
1517 {
1518 .ident = "Dell Optiplex 7000",
1519 .matches = {
1520 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1521 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7000"),
1522 },
1523 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1524 },
1525 {
1526 .ident = "Dell XPS 9315",
1527 .matches = {
1528 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1529 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS 9315"),
1530 },
1531 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_30A3_31A3],
1532 },
1533 { }
1534};
1535
1536/*
1537 * Legacy SMM backend driver.
1538 */
1539static int __init dell_smm_probe(struct platform_device *pdev)
1540{
1541 int ret;
1542
1543 ret = dell_smm_init_data(dev: &pdev->dev, ops: &i8k_smm_ops);
1544 if (ret < 0)
1545 return ret;
1546
1547 ret = dell_smm_init_hwmon(dev: &pdev->dev);
1548 if (ret)
1549 return ret;
1550
1551 i8k_init_procfs(dev: &pdev->dev);
1552
1553 return 0;
1554}
1555
1556static struct platform_driver dell_smm_driver = {
1557 .driver = {
1558 .name = KBUILD_MODNAME,
1559 },
1560};
1561
1562static struct platform_device *dell_smm_device;
1563
1564/*
1565 * WMI SMM backend driver.
1566 */
1567static int dell_smm_wmi_probe(struct wmi_device *wdev, const void *context)
1568{
1569 struct dell_smm_ops *ops;
1570 int ret;
1571
1572 ops = devm_kzalloc(dev: &wdev->dev, size: sizeof(*ops), GFP_KERNEL);
1573 if (!ops)
1574 return -ENOMEM;
1575
1576 ops->smm_call = wmi_smm_call;
1577 ops->smm_dev = &wdev->dev;
1578
1579 if (dell_smm_get_signature(ops, I8K_SMM_GET_DELL_SIG1) &&
1580 dell_smm_get_signature(ops, I8K_SMM_GET_DELL_SIG2))
1581 return -ENODEV;
1582
1583 ret = dell_smm_init_data(dev: &wdev->dev, ops);
1584 if (ret < 0)
1585 return ret;
1586
1587 return dell_smm_init_hwmon(dev: &wdev->dev);
1588}
1589
1590static const struct wmi_device_id dell_smm_wmi_id_table[] = {
1591 { DELL_SMM_WMI_GUID, NULL },
1592 { }
1593};
1594MODULE_DEVICE_TABLE(wmi, dell_smm_wmi_id_table);
1595
1596static struct wmi_driver dell_smm_wmi_driver = {
1597 .driver = {
1598 .name = KBUILD_MODNAME,
1599 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
1600 },
1601 .id_table = dell_smm_wmi_id_table,
1602 .probe = dell_smm_wmi_probe,
1603 .no_singleton = true,
1604};
1605
1606/*
1607 * Probe for the presence of a supported laptop.
1608 */
1609static void __init dell_smm_init_dmi(void)
1610{
1611 struct i8k_fan_control_data *control;
1612 struct i8k_config_data *config;
1613 const struct dmi_system_id *id;
1614
1615 if (dmi_check_system(list: i8k_blacklist_fan_support_dmi_table)) {
1616 if (!force) {
1617 pr_notice("Disabling fan support due to BIOS bugs\n");
1618 disallow_fan_support = true;
1619 } else {
1620 pr_warn("Enabling fan support despite BIOS bugs\n");
1621 }
1622 }
1623
1624 if (dmi_check_system(list: i8k_blacklist_fan_type_dmi_table)) {
1625 if (!force) {
1626 pr_notice("Disabling fan type call due to BIOS bugs\n");
1627 disallow_fan_type_call = true;
1628 } else {
1629 pr_warn("Enabling fan type call despite BIOS bugs\n");
1630 }
1631 }
1632
1633 /*
1634 * Set fan multiplier and maximal fan speed from DMI config.
1635 * Values specified in module parameters override values from DMI.
1636 */
1637 id = dmi_first_match(list: i8k_config_dmi_table);
1638 if (id && id->driver_data) {
1639 config = id->driver_data;
1640 if (!fan_mult && config->fan_mult)
1641 fan_mult = config->fan_mult;
1642
1643 if (!fan_max && config->fan_max)
1644 fan_max = config->fan_max;
1645 }
1646
1647 id = dmi_first_match(list: i8k_whitelist_fan_control);
1648 if (id && id->driver_data) {
1649 control = id->driver_data;
1650 manual_fan = control->manual_fan;
1651 auto_fan = control->auto_fan;
1652
1653 pr_info("Enabling support for setting automatic/manual fan control\n");
1654 }
1655}
1656
1657static int __init dell_smm_legacy_check(void)
1658{
1659 if (!dmi_check_system(list: i8k_dmi_table)) {
1660 if (!ignore_dmi && !force)
1661 return -ENODEV;
1662
1663 pr_info("Probing for legacy SMM handler on unsupported machine\n");
1664 pr_info("vendor=%s, model=%s, version=%s\n",
1665 i8k_get_dmi_data(DMI_SYS_VENDOR),
1666 i8k_get_dmi_data(DMI_PRODUCT_NAME),
1667 i8k_get_dmi_data(DMI_BIOS_VERSION));
1668 }
1669
1670 if (dell_smm_get_signature(ops: &i8k_smm_ops, I8K_SMM_GET_DELL_SIG1) &&
1671 dell_smm_get_signature(ops: &i8k_smm_ops, I8K_SMM_GET_DELL_SIG2)) {
1672 if (!force)
1673 return -ENODEV;
1674
1675 pr_warn("Forcing legacy SMM calls on a possibly incompatible machine\n");
1676 }
1677
1678 return 0;
1679}
1680
1681static int __init i8k_init(void)
1682{
1683 int ret;
1684
1685 dell_smm_init_dmi();
1686
1687 ret = dell_smm_legacy_check();
1688 if (ret < 0) {
1689 /*
1690 * On modern machines, SMM communication happens over WMI, meaning
1691 * the SMM handler might not react to legacy SMM calls.
1692 */
1693 return wmi_driver_register(&dell_smm_wmi_driver);
1694 }
1695
1696 dell_smm_device = platform_create_bundle(&dell_smm_driver, dell_smm_probe, NULL, 0, NULL,
1697 0);
1698
1699 return PTR_ERR_OR_ZERO(ptr: dell_smm_device);
1700}
1701
1702static void __exit i8k_exit(void)
1703{
1704 if (dell_smm_device) {
1705 platform_device_unregister(dell_smm_device);
1706 platform_driver_unregister(&dell_smm_driver);
1707 } else {
1708 wmi_driver_unregister(driver: &dell_smm_wmi_driver);
1709 }
1710}
1711
1712module_init(i8k_init);
1713module_exit(i8k_exit);
1714

source code of linux/drivers/hwmon/dell-smm-hwmon.c