1// SPDX-License-Identifier: GPL-2.0-only
2/* acpi_thermal_rel.c driver for exporting ACPI thermal relationship
3 *
4 * Copyright (c) 2014 Intel Corp
5 */
6
7/*
8 * Two functionalities included:
9 * 1. Export _TRT, _ART, via misc device interface to the userspace.
10 * 2. Provide parsing result to kernel drivers
11 *
12 */
13#include <linux/init.h>
14#include <linux/export.h>
15#include <linux/module.h>
16#include <linux/device.h>
17#include <linux/platform_device.h>
18#include <linux/io.h>
19#include <linux/acpi.h>
20#include <linux/uaccess.h>
21#include <linux/miscdevice.h>
22#include <linux/fs.h>
23#include "acpi_thermal_rel.h"
24
25static acpi_handle acpi_thermal_rel_handle;
26static DEFINE_SPINLOCK(acpi_thermal_rel_chrdev_lock);
27static int acpi_thermal_rel_chrdev_count; /* #times opened */
28static int acpi_thermal_rel_chrdev_exclu; /* already open exclusive? */
29
30static int acpi_thermal_rel_open(struct inode *inode, struct file *file)
31{
32 spin_lock(lock: &acpi_thermal_rel_chrdev_lock);
33 if (acpi_thermal_rel_chrdev_exclu ||
34 (acpi_thermal_rel_chrdev_count && (file->f_flags & O_EXCL))) {
35 spin_unlock(lock: &acpi_thermal_rel_chrdev_lock);
36 return -EBUSY;
37 }
38
39 if (file->f_flags & O_EXCL)
40 acpi_thermal_rel_chrdev_exclu = 1;
41 acpi_thermal_rel_chrdev_count++;
42
43 spin_unlock(lock: &acpi_thermal_rel_chrdev_lock);
44
45 return nonseekable_open(inode, filp: file);
46}
47
48static int acpi_thermal_rel_release(struct inode *inode, struct file *file)
49{
50 spin_lock(lock: &acpi_thermal_rel_chrdev_lock);
51 acpi_thermal_rel_chrdev_count--;
52 acpi_thermal_rel_chrdev_exclu = 0;
53 spin_unlock(lock: &acpi_thermal_rel_chrdev_lock);
54
55 return 0;
56}
57
58/**
59 * acpi_parse_trt - Thermal Relationship Table _TRT for passive cooling
60 *
61 * @handle: ACPI handle of the device contains _TRT
62 * @trt_count: the number of valid entries resulted from parsing _TRT
63 * @trtp: pointer to pointer of array of _TRT entries in parsing result
64 * @create_dev: whether to create platform devices for target and source
65 *
66 */
67int acpi_parse_trt(acpi_handle handle, int *trt_count, struct trt **trtp,
68 bool create_dev)
69{
70 acpi_status status;
71 int result = 0;
72 int i;
73 int nr_bad_entries = 0;
74 struct trt *trts;
75 union acpi_object *p;
76 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
77 struct acpi_buffer element = { 0, NULL };
78 struct acpi_buffer trt_format = { sizeof("RRNNNNNN"), "RRNNNNNN" };
79
80 status = acpi_evaluate_object(object: handle, pathname: "_TRT", NULL, return_object_buffer: &buffer);
81 if (ACPI_FAILURE(status))
82 return -ENODEV;
83
84 p = buffer.pointer;
85 if (!p || (p->type != ACPI_TYPE_PACKAGE)) {
86 pr_err("Invalid _TRT data\n");
87 result = -EFAULT;
88 goto end;
89 }
90
91 *trt_count = p->package.count;
92 trts = kcalloc(n: *trt_count, size: sizeof(struct trt), GFP_KERNEL);
93 if (!trts) {
94 result = -ENOMEM;
95 goto end;
96 }
97
98 for (i = 0; i < *trt_count; i++) {
99 struct trt *trt = &trts[i - nr_bad_entries];
100
101 element.length = sizeof(struct trt);
102 element.pointer = trt;
103
104 status = acpi_extract_package(package: &(p->package.elements[i]),
105 format: &trt_format, buffer: &element);
106 if (ACPI_FAILURE(status)) {
107 nr_bad_entries++;
108 pr_warn("_TRT package %d is invalid, ignored\n", i);
109 continue;
110 }
111 if (!create_dev)
112 continue;
113
114 if (!acpi_fetch_acpi_dev(handle: trt->source))
115 pr_warn("Failed to get source ACPI device\n");
116
117 if (!acpi_fetch_acpi_dev(handle: trt->target))
118 pr_warn("Failed to get target ACPI device\n");
119 }
120
121 result = 0;
122
123 *trtp = trts;
124 /* don't count bad entries */
125 *trt_count -= nr_bad_entries;
126end:
127 kfree(objp: buffer.pointer);
128 return result;
129}
130EXPORT_SYMBOL(acpi_parse_trt);
131
132/**
133 * acpi_parse_art - Parse Active Relationship Table _ART
134 *
135 * @handle: ACPI handle of the device contains _ART
136 * @art_count: the number of valid entries resulted from parsing _ART
137 * @artp: pointer to pointer of array of art entries in parsing result
138 * @create_dev: whether to create platform devices for target and source
139 *
140 */
141int acpi_parse_art(acpi_handle handle, int *art_count, struct art **artp,
142 bool create_dev)
143{
144 acpi_status status;
145 int result = 0;
146 int i;
147 int nr_bad_entries = 0;
148 struct art *arts;
149 union acpi_object *p;
150 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
151 struct acpi_buffer element = { 0, NULL };
152 struct acpi_buffer art_format = {
153 sizeof("RRNNNNNNNNNNN"), "RRNNNNNNNNNNN" };
154
155 status = acpi_evaluate_object(object: handle, pathname: "_ART", NULL, return_object_buffer: &buffer);
156 if (ACPI_FAILURE(status))
157 return -ENODEV;
158
159 p = buffer.pointer;
160 if (!p || (p->type != ACPI_TYPE_PACKAGE)) {
161 pr_err("Invalid _ART data\n");
162 result = -EFAULT;
163 goto end;
164 }
165
166 /* ignore p->package.elements[0], as this is _ART Revision field */
167 *art_count = p->package.count - 1;
168 arts = kcalloc(n: *art_count, size: sizeof(struct art), GFP_KERNEL);
169 if (!arts) {
170 result = -ENOMEM;
171 goto end;
172 }
173
174 for (i = 0; i < *art_count; i++) {
175 struct art *art = &arts[i - nr_bad_entries];
176
177 element.length = sizeof(struct art);
178 element.pointer = art;
179
180 status = acpi_extract_package(package: &(p->package.elements[i + 1]),
181 format: &art_format, buffer: &element);
182 if (ACPI_FAILURE(status)) {
183 pr_warn("_ART package %d is invalid, ignored", i);
184 nr_bad_entries++;
185 continue;
186 }
187 if (!create_dev)
188 continue;
189
190 if (!acpi_fetch_acpi_dev(handle: art->source))
191 pr_warn("Failed to get source ACPI device\n");
192
193 if (!acpi_fetch_acpi_dev(handle: art->target))
194 pr_warn("Failed to get target ACPI device\n");
195 }
196
197 *artp = arts;
198 /* don't count bad entries */
199 *art_count -= nr_bad_entries;
200end:
201 kfree(objp: buffer.pointer);
202 return result;
203}
204EXPORT_SYMBOL(acpi_parse_art);
205
206/*
207 * acpi_parse_psvt - Passive Table (PSVT) for passive cooling
208 *
209 * @handle: ACPI handle of the device which contains PSVT
210 * @psvt_count: the number of valid entries resulted from parsing PSVT
211 * @psvtp: pointer to array of psvt entries
212 *
213 */
214static int acpi_parse_psvt(acpi_handle handle, int *psvt_count, struct psvt **psvtp)
215{
216 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
217 int nr_bad_entries = 0, revision = 0;
218 union acpi_object *p;
219 acpi_status status;
220 int i, result = 0;
221 struct psvt *psvts;
222
223 if (!acpi_has_method(handle, name: "PSVT"))
224 return -ENODEV;
225
226 status = acpi_evaluate_object(object: handle, pathname: "PSVT", NULL, return_object_buffer: &buffer);
227 if (ACPI_FAILURE(status))
228 return -ENODEV;
229
230 p = buffer.pointer;
231 if (!p || (p->type != ACPI_TYPE_PACKAGE)) {
232 result = -EFAULT;
233 goto end;
234 }
235
236 /* first package is the revision number */
237 if (p->package.count > 0) {
238 union acpi_object *prev = &(p->package.elements[0]);
239
240 if (prev->type == ACPI_TYPE_INTEGER)
241 revision = (int)prev->integer.value;
242 } else {
243 result = -EFAULT;
244 goto end;
245 }
246
247 /* Support only version 2 */
248 if (revision != 2) {
249 result = -EFAULT;
250 goto end;
251 }
252
253 *psvt_count = p->package.count - 1;
254 if (!*psvt_count) {
255 result = -EFAULT;
256 goto end;
257 }
258
259 psvts = kcalloc(n: *psvt_count, size: sizeof(*psvts), GFP_KERNEL);
260 if (!psvts) {
261 result = -ENOMEM;
262 goto end;
263 }
264
265 /* Start index is 1 because the first package is the revision number */
266 for (i = 1; i < p->package.count; i++) {
267 struct acpi_buffer psvt_int_format = { sizeof("RRNNNNNNNNNN"), "RRNNNNNNNNNN" };
268 struct acpi_buffer psvt_str_format = { sizeof("RRNNNNNSNNNN"), "RRNNNNNSNNNN" };
269 union acpi_object *package = &(p->package.elements[i]);
270 struct psvt *psvt = &psvts[i - 1 - nr_bad_entries];
271 struct acpi_buffer *psvt_format = &psvt_int_format;
272 struct acpi_buffer element = { 0, NULL };
273 union acpi_object *knob;
274 struct acpi_device *res;
275 struct psvt *psvt_ptr;
276
277 element.length = ACPI_ALLOCATE_BUFFER;
278 element.pointer = NULL;
279
280 if (package->package.count >= ACPI_NR_PSVT_ELEMENTS) {
281 knob = &(package->package.elements[ACPI_PSVT_CONTROL_KNOB]);
282 } else {
283 nr_bad_entries++;
284 pr_info("PSVT package %d is invalid, ignored\n", i);
285 continue;
286 }
287
288 if (knob->type == ACPI_TYPE_STRING) {
289 psvt_format = &psvt_str_format;
290 if (knob->string.length > ACPI_LIMIT_STR_MAX_LEN - 1) {
291 pr_info("PSVT package %d limit string len exceeds max\n", i);
292 knob->string.length = ACPI_LIMIT_STR_MAX_LEN - 1;
293 }
294 }
295
296 status = acpi_extract_package(package: &(p->package.elements[i]), format: psvt_format, buffer: &element);
297 if (ACPI_FAILURE(status)) {
298 nr_bad_entries++;
299 pr_info("PSVT package %d is invalid, ignored\n", i);
300 continue;
301 }
302
303 psvt_ptr = (struct psvt *)element.pointer;
304
305 memcpy(psvt, psvt_ptr, sizeof(*psvt));
306
307 /* The limit element can be string or U64 */
308 psvt->control_knob_type = (u64)knob->type;
309
310 if (knob->type == ACPI_TYPE_STRING) {
311 memset(&psvt->limit, 0, sizeof(u64));
312 strncpy(p: psvt->limit.string, q: psvt_ptr->limit.str_ptr, size: knob->string.length);
313 } else {
314 psvt->limit.integer = psvt_ptr->limit.integer;
315 }
316
317 kfree(objp: element.pointer);
318
319 res = acpi_fetch_acpi_dev(handle: psvt->source);
320 if (!res) {
321 nr_bad_entries++;
322 pr_info("Failed to get source ACPI device\n");
323 continue;
324 }
325
326 res = acpi_fetch_acpi_dev(handle: psvt->target);
327 if (!res) {
328 nr_bad_entries++;
329 pr_info("Failed to get target ACPI device\n");
330 continue;
331 }
332 }
333
334 /* don't count bad entries */
335 *psvt_count -= nr_bad_entries;
336
337 if (!*psvt_count) {
338 result = -EFAULT;
339 kfree(objp: psvts);
340 goto end;
341 }
342
343 *psvtp = psvts;
344
345 return 0;
346
347end:
348 kfree(objp: buffer.pointer);
349 return result;
350}
351
352/* get device name from acpi handle */
353static void get_single_name(acpi_handle handle, char *name)
354{
355 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER};
356
357 if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer)))
358 pr_warn("Failed to get device name from acpi handle\n");
359 else {
360 memcpy(name, buffer.pointer, ACPI_NAMESEG_SIZE);
361 kfree(objp: buffer.pointer);
362 }
363}
364
365static int fill_art(char __user *ubuf)
366{
367 int i;
368 int ret;
369 int count;
370 int art_len;
371 struct art *arts = NULL;
372 union art_object *art_user;
373
374 ret = acpi_parse_art(acpi_thermal_rel_handle, &count, &arts, false);
375 if (ret)
376 goto free_art;
377 art_len = count * sizeof(union art_object);
378 art_user = kzalloc(size: art_len, GFP_KERNEL);
379 if (!art_user) {
380 ret = -ENOMEM;
381 goto free_art;
382 }
383 /* now fill in user art data */
384 for (i = 0; i < count; i++) {
385 /* userspace art needs device name instead of acpi reference */
386 get_single_name(handle: arts[i].source, name: art_user[i].source_device);
387 get_single_name(handle: arts[i].target, name: art_user[i].target_device);
388 /* copy the rest int data in addition to source and target */
389 BUILD_BUG_ON(sizeof(art_user[i].data) !=
390 sizeof(u64) * (ACPI_NR_ART_ELEMENTS - 2));
391 memcpy(&art_user[i].data, &arts[i].data, sizeof(art_user[i].data));
392 }
393
394 if (copy_to_user(to: ubuf, from: art_user, n: art_len))
395 ret = -EFAULT;
396 kfree(objp: art_user);
397free_art:
398 kfree(objp: arts);
399 return ret;
400}
401
402static int fill_trt(char __user *ubuf)
403{
404 int i;
405 int ret;
406 int count;
407 int trt_len;
408 struct trt *trts = NULL;
409 union trt_object *trt_user;
410
411 ret = acpi_parse_trt(acpi_thermal_rel_handle, &count, &trts, false);
412 if (ret)
413 goto free_trt;
414 trt_len = count * sizeof(union trt_object);
415 trt_user = kzalloc(size: trt_len, GFP_KERNEL);
416 if (!trt_user) {
417 ret = -ENOMEM;
418 goto free_trt;
419 }
420 /* now fill in user trt data */
421 for (i = 0; i < count; i++) {
422 /* userspace trt needs device name instead of acpi reference */
423 get_single_name(handle: trts[i].source, name: trt_user[i].source_device);
424 get_single_name(handle: trts[i].target, name: trt_user[i].target_device);
425 trt_user[i].sample_period = trts[i].sample_period;
426 trt_user[i].influence = trts[i].influence;
427 }
428
429 if (copy_to_user(to: ubuf, from: trt_user, n: trt_len))
430 ret = -EFAULT;
431 kfree(objp: trt_user);
432free_trt:
433 kfree(objp: trts);
434 return ret;
435}
436
437static int fill_psvt(char __user *ubuf)
438{
439 int i, ret, count, psvt_len;
440 union psvt_object *psvt_user;
441 struct psvt *psvts;
442
443 ret = acpi_parse_psvt(handle: acpi_thermal_rel_handle, psvt_count: &count, psvtp: &psvts);
444 if (ret)
445 return ret;
446
447 psvt_len = count * sizeof(*psvt_user);
448
449 psvt_user = kzalloc(size: psvt_len, GFP_KERNEL);
450 if (!psvt_user) {
451 ret = -ENOMEM;
452 goto free_psvt;
453 }
454
455 /* now fill in user psvt data */
456 for (i = 0; i < count; i++) {
457 /* userspace psvt needs device name instead of acpi reference */
458 get_single_name(handle: psvts[i].source, name: psvt_user[i].source_device);
459 get_single_name(handle: psvts[i].target, name: psvt_user[i].target_device);
460
461 psvt_user[i].priority = psvts[i].priority;
462 psvt_user[i].sample_period = psvts[i].sample_period;
463 psvt_user[i].passive_temp = psvts[i].passive_temp;
464 psvt_user[i].source_domain = psvts[i].source_domain;
465 psvt_user[i].control_knob = psvts[i].control_knob;
466 psvt_user[i].step_size = psvts[i].step_size;
467 psvt_user[i].limit_coeff = psvts[i].limit_coeff;
468 psvt_user[i].unlimit_coeff = psvts[i].unlimit_coeff;
469 psvt_user[i].control_knob_type = psvts[i].control_knob_type;
470 if (psvt_user[i].control_knob_type == ACPI_TYPE_STRING)
471 strncpy(p: psvt_user[i].limit.string, q: psvts[i].limit.string,
472 ACPI_LIMIT_STR_MAX_LEN);
473 else
474 psvt_user[i].limit.integer = psvts[i].limit.integer;
475
476 }
477
478 if (copy_to_user(to: ubuf, from: psvt_user, n: psvt_len))
479 ret = -EFAULT;
480
481 kfree(objp: psvt_user);
482
483free_psvt:
484 kfree(objp: psvts);
485 return ret;
486}
487
488static long acpi_thermal_rel_ioctl(struct file *f, unsigned int cmd,
489 unsigned long __arg)
490{
491 int ret = 0;
492 unsigned long length = 0;
493 int count = 0;
494 char __user *arg = (void __user *)__arg;
495 struct trt *trts = NULL;
496 struct art *arts = NULL;
497 struct psvt *psvts;
498
499 switch (cmd) {
500 case ACPI_THERMAL_GET_TRT_COUNT:
501 ret = acpi_parse_trt(acpi_thermal_rel_handle, &count,
502 &trts, false);
503 kfree(objp: trts);
504 if (!ret)
505 return put_user(count, (unsigned long __user *)__arg);
506 return ret;
507 case ACPI_THERMAL_GET_TRT_LEN:
508 ret = acpi_parse_trt(acpi_thermal_rel_handle, &count,
509 &trts, false);
510 kfree(objp: trts);
511 length = count * sizeof(union trt_object);
512 if (!ret)
513 return put_user(length, (unsigned long __user *)__arg);
514 return ret;
515 case ACPI_THERMAL_GET_TRT:
516 return fill_trt(ubuf: arg);
517 case ACPI_THERMAL_GET_ART_COUNT:
518 ret = acpi_parse_art(acpi_thermal_rel_handle, &count,
519 &arts, false);
520 kfree(objp: arts);
521 if (!ret)
522 return put_user(count, (unsigned long __user *)__arg);
523 return ret;
524 case ACPI_THERMAL_GET_ART_LEN:
525 ret = acpi_parse_art(acpi_thermal_rel_handle, &count,
526 &arts, false);
527 kfree(objp: arts);
528 length = count * sizeof(union art_object);
529 if (!ret)
530 return put_user(length, (unsigned long __user *)__arg);
531 return ret;
532
533 case ACPI_THERMAL_GET_ART:
534 return fill_art(ubuf: arg);
535
536 case ACPI_THERMAL_GET_PSVT_COUNT:
537 ret = acpi_parse_psvt(handle: acpi_thermal_rel_handle, psvt_count: &count, psvtp: &psvts);
538 if (!ret) {
539 kfree(objp: psvts);
540 return put_user(count, (unsigned long __user *)__arg);
541 }
542 return ret;
543
544 case ACPI_THERMAL_GET_PSVT_LEN:
545 /* total length of the data retrieved (count * PSVT entry size) */
546 ret = acpi_parse_psvt(handle: acpi_thermal_rel_handle, psvt_count: &count, psvtp: &psvts);
547 length = count * sizeof(union psvt_object);
548 if (!ret) {
549 kfree(objp: psvts);
550 return put_user(length, (unsigned long __user *)__arg);
551 }
552 return ret;
553
554 case ACPI_THERMAL_GET_PSVT:
555 return fill_psvt(ubuf: arg);
556
557 default:
558 return -ENOTTY;
559 }
560}
561
562static const struct file_operations acpi_thermal_rel_fops = {
563 .owner = THIS_MODULE,
564 .open = acpi_thermal_rel_open,
565 .release = acpi_thermal_rel_release,
566 .unlocked_ioctl = acpi_thermal_rel_ioctl,
567 .llseek = no_llseek,
568};
569
570static struct miscdevice acpi_thermal_rel_misc_device = {
571 .minor = MISC_DYNAMIC_MINOR,
572 "acpi_thermal_rel",
573 &acpi_thermal_rel_fops
574};
575
576int acpi_thermal_rel_misc_device_add(acpi_handle handle)
577{
578 acpi_thermal_rel_handle = handle;
579
580 return misc_register(misc: &acpi_thermal_rel_misc_device);
581}
582EXPORT_SYMBOL(acpi_thermal_rel_misc_device_add);
583
584int acpi_thermal_rel_misc_device_remove(acpi_handle handle)
585{
586 misc_deregister(misc: &acpi_thermal_rel_misc_device);
587
588 return 0;
589}
590EXPORT_SYMBOL(acpi_thermal_rel_misc_device_remove);
591
592MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>");
593MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@intel.com");
594MODULE_DESCRIPTION("Intel acpi thermal rel misc dev driver");
595MODULE_LICENSE("GPL v2");
596

source code of linux/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c