1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Architecture-specific ACPI-based support for suspend-to-idle.
4 *
5 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
6 * Author: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
7 * Author: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
8 *
9 * On platforms supporting the Low Power S0 Idle interface there is an ACPI
10 * device object with the PNP0D80 compatible device ID (System Power Management
11 * Controller) and a specific _DSM method under it. That method, if present,
12 * can be used to indicate to the platform that the OS is transitioning into a
13 * low-power state in which certain types of activity are not desirable or that
14 * it is leaving such a state, which allows the platform to adjust its operation
15 * mode accordingly.
16 */
17
18#include <linux/acpi.h>
19#include <linux/device.h>
20#include <linux/dmi.h>
21#include <linux/suspend.h>
22
23#include "../sleep.h"
24
25#ifdef CONFIG_SUSPEND
26
27static bool sleep_no_lps0 __read_mostly;
28module_param(sleep_no_lps0, bool, 0644);
29MODULE_PARM_DESC(sleep_no_lps0, "Do not use the special LPS0 device interface");
30
31static const struct acpi_device_id lps0_device_ids[] = {
32 {"PNP0D80", },
33 {.id: "", },
34};
35
36/* Microsoft platform agnostic UUID */
37#define ACPI_LPS0_DSM_UUID_MICROSOFT "11e00d56-ce64-47ce-837b-1f898f9aa461"
38
39#define ACPI_LPS0_DSM_UUID "c4eb40a0-6cd2-11e2-bcfd-0800200c9a66"
40
41#define ACPI_LPS0_GET_DEVICE_CONSTRAINTS 1
42#define ACPI_LPS0_SCREEN_OFF 3
43#define ACPI_LPS0_SCREEN_ON 4
44#define ACPI_LPS0_ENTRY 5
45#define ACPI_LPS0_EXIT 6
46#define ACPI_LPS0_MS_ENTRY 7
47#define ACPI_LPS0_MS_EXIT 8
48
49/* AMD */
50#define ACPI_LPS0_DSM_UUID_AMD "e3f32452-febc-43ce-9039-932122d37721"
51#define ACPI_LPS0_ENTRY_AMD 2
52#define ACPI_LPS0_EXIT_AMD 3
53#define ACPI_LPS0_SCREEN_OFF_AMD 4
54#define ACPI_LPS0_SCREEN_ON_AMD 5
55
56static acpi_handle lps0_device_handle;
57static guid_t lps0_dsm_guid;
58static int lps0_dsm_func_mask;
59
60static guid_t lps0_dsm_guid_microsoft;
61static int lps0_dsm_func_mask_microsoft;
62static int lps0_dsm_state;
63
64/* Device constraint entry structure */
65struct lpi_device_info {
66 char *name;
67 int enabled;
68 union acpi_object *package;
69};
70
71/* Constraint package structure */
72struct lpi_device_constraint {
73 int uid;
74 int min_dstate;
75 int function_states;
76};
77
78struct lpi_constraints {
79 acpi_handle handle;
80 int min_dstate;
81};
82
83/* AMD Constraint package structure */
84struct lpi_device_constraint_amd {
85 char *name;
86 int enabled;
87 int function_states;
88 int min_dstate;
89};
90
91static LIST_HEAD(lps0_s2idle_devops_head);
92
93static struct lpi_constraints *lpi_constraints_table;
94static int lpi_constraints_table_size;
95static int rev_id;
96
97#define for_each_lpi_constraint(entry) \
98 for (int i = 0; \
99 entry = &lpi_constraints_table[i], i < lpi_constraints_table_size; \
100 i++)
101
102static void lpi_device_get_constraints_amd(void)
103{
104 union acpi_object *out_obj;
105 int i, j, k;
106
107 out_obj = acpi_evaluate_dsm_typed(handle: lps0_device_handle, guid: &lps0_dsm_guid,
108 rev: rev_id, ACPI_LPS0_GET_DEVICE_CONSTRAINTS,
109 NULL, ACPI_TYPE_PACKAGE);
110
111 acpi_handle_debug(lps0_device_handle, "_DSM function 1 eval %s\n",
112 out_obj ? "successful" : "failed");
113
114 if (!out_obj)
115 return;
116
117 for (i = 0; i < out_obj->package.count; i++) {
118 union acpi_object *package = &out_obj->package.elements[i];
119
120 if (package->type == ACPI_TYPE_PACKAGE) {
121 if (lpi_constraints_table) {
122 acpi_handle_err(lps0_device_handle,
123 "Duplicate constraints list\n");
124 goto free_acpi_buffer;
125 }
126
127 lpi_constraints_table = kcalloc(package->package.count,
128 sizeof(*lpi_constraints_table),
129 GFP_KERNEL);
130
131 if (!lpi_constraints_table)
132 goto free_acpi_buffer;
133
134 acpi_handle_debug(lps0_device_handle,
135 "LPI: constraints list begin:\n");
136
137 for (j = 0; j < package->package.count; j++) {
138 union acpi_object *info_obj = &package->package.elements[j];
139 struct lpi_device_constraint_amd dev_info = {};
140 struct lpi_constraints *list;
141 acpi_status status;
142
143 list = &lpi_constraints_table[lpi_constraints_table_size];
144
145 for (k = 0; k < info_obj->package.count; k++) {
146 union acpi_object *obj = &info_obj->package.elements[k];
147
148 switch (k) {
149 case 0:
150 dev_info.enabled = obj->integer.value;
151 break;
152 case 1:
153 dev_info.name = obj->string.pointer;
154 break;
155 case 2:
156 dev_info.function_states = obj->integer.value;
157 break;
158 case 3:
159 dev_info.min_dstate = obj->integer.value;
160 break;
161 }
162 }
163
164 acpi_handle_debug(lps0_device_handle,
165 "Name:%s, Enabled: %d, States: %d, MinDstate: %d\n",
166 dev_info.name,
167 dev_info.enabled,
168 dev_info.function_states,
169 dev_info.min_dstate);
170
171 if (!dev_info.enabled || !dev_info.name ||
172 !dev_info.min_dstate)
173 continue;
174
175 status = acpi_get_handle(NULL, pathname: dev_info.name, ret_handle: &list->handle);
176 if (ACPI_FAILURE(status))
177 continue;
178
179 list->min_dstate = dev_info.min_dstate;
180
181 lpi_constraints_table_size++;
182 }
183 }
184 }
185
186 acpi_handle_debug(lps0_device_handle, "LPI: constraints list end\n");
187
188free_acpi_buffer:
189 ACPI_FREE(out_obj);
190}
191
192static void lpi_device_get_constraints(void)
193{
194 union acpi_object *out_obj;
195 int i;
196
197 out_obj = acpi_evaluate_dsm_typed(handle: lps0_device_handle, guid: &lps0_dsm_guid,
198 rev: 1, ACPI_LPS0_GET_DEVICE_CONSTRAINTS,
199 NULL, ACPI_TYPE_PACKAGE);
200
201 acpi_handle_debug(lps0_device_handle, "_DSM function 1 eval %s\n",
202 out_obj ? "successful" : "failed");
203
204 if (!out_obj)
205 return;
206
207 lpi_constraints_table = kcalloc(out_obj->package.count,
208 sizeof(*lpi_constraints_table),
209 GFP_KERNEL);
210 if (!lpi_constraints_table)
211 goto free_acpi_buffer;
212
213 acpi_handle_debug(lps0_device_handle, "LPI: constraints list begin:\n");
214
215 for (i = 0; i < out_obj->package.count; i++) {
216 struct lpi_constraints *constraint;
217 acpi_status status;
218 union acpi_object *package = &out_obj->package.elements[i];
219 struct lpi_device_info info = { };
220 int package_count = 0, j;
221
222 if (!package)
223 continue;
224
225 for (j = 0; j < package->package.count; j++) {
226 union acpi_object *element =
227 &(package->package.elements[j]);
228
229 switch (element->type) {
230 case ACPI_TYPE_INTEGER:
231 info.enabled = element->integer.value;
232 break;
233 case ACPI_TYPE_STRING:
234 info.name = element->string.pointer;
235 break;
236 case ACPI_TYPE_PACKAGE:
237 package_count = element->package.count;
238 info.package = element->package.elements;
239 break;
240 }
241 }
242
243 if (!info.enabled || !info.package || !info.name)
244 continue;
245
246 constraint = &lpi_constraints_table[lpi_constraints_table_size];
247
248 status = acpi_get_handle(NULL, pathname: info.name, ret_handle: &constraint->handle);
249 if (ACPI_FAILURE(status))
250 continue;
251
252 acpi_handle_debug(lps0_device_handle,
253 "index:%d Name:%s\n", i, info.name);
254
255 constraint->min_dstate = -1;
256
257 for (j = 0; j < package_count; j++) {
258 union acpi_object *info_obj = &info.package[j];
259 union acpi_object *cnstr_pkg;
260 union acpi_object *obj;
261 struct lpi_device_constraint dev_info;
262
263 switch (info_obj->type) {
264 case ACPI_TYPE_INTEGER:
265 /* version */
266 break;
267 case ACPI_TYPE_PACKAGE:
268 if (info_obj->package.count < 2)
269 break;
270
271 cnstr_pkg = info_obj->package.elements;
272 obj = &cnstr_pkg[0];
273 dev_info.uid = obj->integer.value;
274 obj = &cnstr_pkg[1];
275 dev_info.min_dstate = obj->integer.value;
276
277 acpi_handle_debug(lps0_device_handle,
278 "uid:%d min_dstate:%s\n",
279 dev_info.uid,
280 acpi_power_state_string(dev_info.min_dstate));
281
282 constraint->min_dstate = dev_info.min_dstate;
283 break;
284 }
285 }
286
287 if (constraint->min_dstate < 0) {
288 acpi_handle_debug(lps0_device_handle,
289 "Incomplete constraint defined\n");
290 continue;
291 }
292
293 lpi_constraints_table_size++;
294 }
295
296 acpi_handle_debug(lps0_device_handle, "LPI: constraints list end\n");
297
298free_acpi_buffer:
299 ACPI_FREE(out_obj);
300}
301
302/**
303 * acpi_get_lps0_constraint - Get the LPS0 constraint for a device.
304 * @adev: Device to get the constraint for.
305 *
306 * The LPS0 constraint is the shallowest (minimum) power state in which the
307 * device can be so as to allow the platform as a whole to achieve additional
308 * energy conservation by utilizing a system-wide low-power state.
309 *
310 * Returns:
311 * - ACPI power state value of the constraint for @adev on success.
312 * - Otherwise, ACPI_STATE_UNKNOWN.
313 */
314int acpi_get_lps0_constraint(struct acpi_device *adev)
315{
316 struct lpi_constraints *entry;
317
318 for_each_lpi_constraint(entry) {
319 if (adev->handle == entry->handle)
320 return entry->min_dstate;
321 }
322
323 return ACPI_STATE_UNKNOWN;
324}
325
326static void lpi_check_constraints(void)
327{
328 struct lpi_constraints *entry;
329
330 for_each_lpi_constraint(entry) {
331 struct acpi_device *adev = acpi_fetch_acpi_dev(handle: entry->handle);
332
333 if (!adev)
334 continue;
335
336 acpi_handle_debug(entry->handle,
337 "LPI: required min power state:%s current power state:%s\n",
338 acpi_power_state_string(entry->min_dstate),
339 acpi_power_state_string(adev->power.state));
340
341 if (!adev->flags.power_manageable) {
342 acpi_handle_info(entry->handle, "LPI: Device not power manageable\n");
343 entry->handle = NULL;
344 continue;
345 }
346
347 if (adev->power.state < entry->min_dstate)
348 acpi_handle_info(entry->handle,
349 "LPI: Constraint not met; min power state:%s current power state:%s\n",
350 acpi_power_state_string(entry->min_dstate),
351 acpi_power_state_string(adev->power.state));
352 }
353}
354
355static bool acpi_s2idle_vendor_amd(void)
356{
357 return boot_cpu_data.x86_vendor == X86_VENDOR_AMD;
358}
359
360static const char *acpi_sleep_dsm_state_to_str(unsigned int state)
361{
362 if (lps0_dsm_func_mask_microsoft || !acpi_s2idle_vendor_amd()) {
363 switch (state) {
364 case ACPI_LPS0_SCREEN_OFF:
365 return "screen off";
366 case ACPI_LPS0_SCREEN_ON:
367 return "screen on";
368 case ACPI_LPS0_ENTRY:
369 return "lps0 entry";
370 case ACPI_LPS0_EXIT:
371 return "lps0 exit";
372 case ACPI_LPS0_MS_ENTRY:
373 return "lps0 ms entry";
374 case ACPI_LPS0_MS_EXIT:
375 return "lps0 ms exit";
376 }
377 } else {
378 switch (state) {
379 case ACPI_LPS0_SCREEN_ON_AMD:
380 return "screen on";
381 case ACPI_LPS0_SCREEN_OFF_AMD:
382 return "screen off";
383 case ACPI_LPS0_ENTRY_AMD:
384 return "lps0 entry";
385 case ACPI_LPS0_EXIT_AMD:
386 return "lps0 exit";
387 }
388 }
389
390 return "unknown";
391}
392
393static void acpi_sleep_run_lps0_dsm(unsigned int func, unsigned int func_mask, guid_t dsm_guid)
394{
395 union acpi_object *out_obj;
396
397 if (!(func_mask & (1 << func)))
398 return;
399
400 out_obj = acpi_evaluate_dsm(handle: lps0_device_handle, guid: &dsm_guid,
401 rev: rev_id, func, NULL);
402 ACPI_FREE(out_obj);
403
404 lps0_dsm_state = func;
405 if (pm_debug_messages_on) {
406 acpi_handle_info(lps0_device_handle,
407 "%s transitioned to state %s\n",
408 out_obj ? "Successfully" : "Failed to",
409 acpi_sleep_dsm_state_to_str(lps0_dsm_state));
410 }
411}
412
413
414static int validate_dsm(acpi_handle handle, const char *uuid, int rev, guid_t *dsm_guid)
415{
416 union acpi_object *obj;
417 int ret = -EINVAL;
418
419 guid_parse(uuid, u: dsm_guid);
420
421 /* Check if the _DSM is present and as expected. */
422 obj = acpi_evaluate_dsm_typed(handle, guid: dsm_guid, rev, func: 0, NULL, ACPI_TYPE_BUFFER);
423 if (!obj || obj->buffer.length == 0 || obj->buffer.length > sizeof(u32)) {
424 acpi_handle_debug(handle,
425 "_DSM UUID %s rev %d function 0 evaluation failed\n", uuid, rev);
426 goto out;
427 }
428
429 ret = *(int *)obj->buffer.pointer;
430 acpi_handle_debug(handle, "_DSM UUID %s rev %d function mask: 0x%x\n", uuid, rev, ret);
431
432out:
433 ACPI_FREE(obj);
434 return ret;
435}
436
437struct amd_lps0_hid_device_data {
438 const bool check_off_by_one;
439};
440
441static const struct amd_lps0_hid_device_data amd_picasso = {
442 .check_off_by_one = true,
443};
444
445static const struct amd_lps0_hid_device_data amd_cezanne = {
446 .check_off_by_one = false,
447};
448
449static const struct acpi_device_id amd_hid_ids[] = {
450 {"AMD0004", (kernel_ulong_t)&amd_picasso, },
451 {.id: "AMD0005", .driver_data: (kernel_ulong_t)&amd_picasso, },
452 {.id: "AMDI0005", .driver_data: (kernel_ulong_t)&amd_picasso, },
453 {.id: "AMDI0006", .driver_data: (kernel_ulong_t)&amd_cezanne, },
454 {}
455};
456
457static int lps0_device_attach(struct acpi_device *adev,
458 const struct acpi_device_id *not_used)
459{
460 if (lps0_device_handle)
461 return 0;
462
463 lps0_dsm_func_mask_microsoft = validate_dsm(handle: adev->handle,
464 ACPI_LPS0_DSM_UUID_MICROSOFT, rev: 0,
465 dsm_guid: &lps0_dsm_guid_microsoft);
466 if (acpi_s2idle_vendor_amd()) {
467 static const struct acpi_device_id *dev_id;
468 const struct amd_lps0_hid_device_data *data;
469
470 for (dev_id = &amd_hid_ids[0]; dev_id->id[0]; dev_id++)
471 if (acpi_dev_hid_uid_match(adev, dev_id->id, NULL))
472 break;
473 if (dev_id->id[0])
474 data = (const struct amd_lps0_hid_device_data *) dev_id->driver_data;
475 else
476 data = &amd_cezanne;
477 lps0_dsm_func_mask = validate_dsm(handle: adev->handle,
478 ACPI_LPS0_DSM_UUID_AMD, rev: rev_id, dsm_guid: &lps0_dsm_guid);
479 if (lps0_dsm_func_mask > 0x3 && data->check_off_by_one) {
480 lps0_dsm_func_mask = (lps0_dsm_func_mask << 1) | 0x1;
481 acpi_handle_debug(adev->handle, "_DSM UUID %s: Adjusted function mask: 0x%x\n",
482 ACPI_LPS0_DSM_UUID_AMD, lps0_dsm_func_mask);
483 } else if (lps0_dsm_func_mask_microsoft > 0 && rev_id) {
484 lps0_dsm_func_mask_microsoft = -EINVAL;
485 acpi_handle_debug(adev->handle, "_DSM Using AMD method\n");
486 }
487 } else {
488 rev_id = 1;
489 lps0_dsm_func_mask = validate_dsm(handle: adev->handle,
490 ACPI_LPS0_DSM_UUID, rev: rev_id, dsm_guid: &lps0_dsm_guid);
491 if (lps0_dsm_func_mask > 0 && lps0_dsm_func_mask_microsoft > 0) {
492 unsigned int func_mask;
493
494 /*
495 * Log a message if the _DSM function sets for two
496 * different UUIDs overlap.
497 */
498 func_mask = lps0_dsm_func_mask & lps0_dsm_func_mask_microsoft;
499 if (func_mask)
500 acpi_handle_info(adev->handle,
501 "Duplicate LPS0 _DSM functions (mask: 0x%x)\n",
502 func_mask);
503 }
504 }
505
506 if (lps0_dsm_func_mask < 0 && lps0_dsm_func_mask_microsoft < 0)
507 return 0; //function evaluation failed
508
509 lps0_device_handle = adev->handle;
510
511 if (acpi_s2idle_vendor_amd())
512 lpi_device_get_constraints_amd();
513 else
514 lpi_device_get_constraints();
515
516 /*
517 * Use suspend-to-idle by default if ACPI_FADT_LOW_POWER_S0 is set in
518 * the FADT and the default suspend mode was not set from the command
519 * line.
520 */
521 if ((acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0) &&
522 mem_sleep_default > PM_SUSPEND_MEM && !acpi_sleep_default_s3) {
523 mem_sleep_current = PM_SUSPEND_TO_IDLE;
524 pr_info("Low-power S0 idle used by default for system suspend\n");
525 }
526
527 /*
528 * Some LPS0 systems, like ASUS Zenbook UX430UNR/i7-8550U, require the
529 * EC GPE to be enabled while suspended for certain wakeup devices to
530 * work, so mark it as wakeup-capable.
531 */
532 acpi_ec_mark_gpe_for_wake();
533
534 return 0;
535}
536
537static struct acpi_scan_handler lps0_handler = {
538 .ids = lps0_device_ids,
539 .attach = lps0_device_attach,
540};
541
542int acpi_s2idle_prepare_late(void)
543{
544 struct acpi_s2idle_dev_ops *handler;
545
546 if (!lps0_device_handle || sleep_no_lps0)
547 return 0;
548
549 if (pm_debug_messages_on)
550 lpi_check_constraints();
551
552 /* Screen off */
553 if (lps0_dsm_func_mask > 0)
554 acpi_sleep_run_lps0_dsm(func: acpi_s2idle_vendor_amd() ?
555 ACPI_LPS0_SCREEN_OFF_AMD :
556 ACPI_LPS0_SCREEN_OFF,
557 func_mask: lps0_dsm_func_mask, dsm_guid: lps0_dsm_guid);
558
559 if (lps0_dsm_func_mask_microsoft > 0)
560 acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF,
561 func_mask: lps0_dsm_func_mask_microsoft, dsm_guid: lps0_dsm_guid_microsoft);
562
563 /* LPS0 entry */
564 if (lps0_dsm_func_mask > 0 && acpi_s2idle_vendor_amd())
565 acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY_AMD,
566 func_mask: lps0_dsm_func_mask, dsm_guid: lps0_dsm_guid);
567
568 if (lps0_dsm_func_mask_microsoft > 0) {
569 /* Modern Standby entry */
570 acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_ENTRY,
571 func_mask: lps0_dsm_func_mask_microsoft, dsm_guid: lps0_dsm_guid_microsoft);
572 acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY,
573 func_mask: lps0_dsm_func_mask_microsoft, dsm_guid: lps0_dsm_guid_microsoft);
574 }
575
576 if (lps0_dsm_func_mask > 0 && !acpi_s2idle_vendor_amd())
577 acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY,
578 func_mask: lps0_dsm_func_mask, dsm_guid: lps0_dsm_guid);
579
580 list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) {
581 if (handler->prepare)
582 handler->prepare();
583 }
584
585 return 0;
586}
587
588void acpi_s2idle_check(void)
589{
590 struct acpi_s2idle_dev_ops *handler;
591
592 if (!lps0_device_handle || sleep_no_lps0)
593 return;
594
595 list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) {
596 if (handler->check)
597 handler->check();
598 }
599}
600
601void acpi_s2idle_restore_early(void)
602{
603 struct acpi_s2idle_dev_ops *handler;
604
605 if (!lps0_device_handle || sleep_no_lps0)
606 return;
607
608 list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node)
609 if (handler->restore)
610 handler->restore();
611
612 /* LPS0 exit */
613 if (lps0_dsm_func_mask > 0)
614 acpi_sleep_run_lps0_dsm(func: acpi_s2idle_vendor_amd() ?
615 ACPI_LPS0_EXIT_AMD :
616 ACPI_LPS0_EXIT,
617 func_mask: lps0_dsm_func_mask, dsm_guid: lps0_dsm_guid);
618
619 if (lps0_dsm_func_mask_microsoft > 0) {
620 acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT,
621 func_mask: lps0_dsm_func_mask_microsoft, dsm_guid: lps0_dsm_guid_microsoft);
622 /* Modern Standby exit */
623 acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_EXIT,
624 func_mask: lps0_dsm_func_mask_microsoft, dsm_guid: lps0_dsm_guid_microsoft);
625 }
626
627 /* Screen on */
628 if (lps0_dsm_func_mask_microsoft > 0)
629 acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON,
630 func_mask: lps0_dsm_func_mask_microsoft, dsm_guid: lps0_dsm_guid_microsoft);
631 if (lps0_dsm_func_mask > 0)
632 acpi_sleep_run_lps0_dsm(func: acpi_s2idle_vendor_amd() ?
633 ACPI_LPS0_SCREEN_ON_AMD :
634 ACPI_LPS0_SCREEN_ON,
635 func_mask: lps0_dsm_func_mask, dsm_guid: lps0_dsm_guid);
636}
637
638static const struct platform_s2idle_ops acpi_s2idle_ops_lps0 = {
639 .begin = acpi_s2idle_begin,
640 .prepare = acpi_s2idle_prepare,
641 .prepare_late = acpi_s2idle_prepare_late,
642 .check = acpi_s2idle_check,
643 .wake = acpi_s2idle_wake,
644 .restore_early = acpi_s2idle_restore_early,
645 .restore = acpi_s2idle_restore,
646 .end = acpi_s2idle_end,
647};
648
649void __init acpi_s2idle_setup(void)
650{
651 acpi_scan_add_handler(handler: &lps0_handler);
652 s2idle_set_ops(ops: &acpi_s2idle_ops_lps0);
653}
654
655int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg)
656{
657 unsigned int sleep_flags;
658
659 if (!lps0_device_handle || sleep_no_lps0)
660 return -ENODEV;
661
662 sleep_flags = lock_system_sleep();
663 list_add(new: &arg->list_node, head: &lps0_s2idle_devops_head);
664 unlock_system_sleep(sleep_flags);
665
666 return 0;
667}
668EXPORT_SYMBOL_GPL(acpi_register_lps0_dev);
669
670void acpi_unregister_lps0_dev(struct acpi_s2idle_dev_ops *arg)
671{
672 unsigned int sleep_flags;
673
674 if (!lps0_device_handle || sleep_no_lps0)
675 return;
676
677 sleep_flags = lock_system_sleep();
678 list_del(entry: &arg->list_node);
679 unlock_system_sleep(sleep_flags);
680}
681EXPORT_SYMBOL_GPL(acpi_unregister_lps0_dev);
682
683#endif /* CONFIG_SUSPEND */
684