GNU Linux-libre 6.7.9-gnu
[releases.git] / drivers / acpi / x86 / s2idle.c
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
27 static bool sleep_no_lps0 __read_mostly;
28 module_param(sleep_no_lps0, bool, 0644);
29 MODULE_PARM_DESC(sleep_no_lps0, "Do not use the special LPS0 device interface");
30
31 static const struct acpi_device_id lps0_device_ids[] = {
32         {"PNP0D80", },
33         {"", },
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
56 static acpi_handle lps0_device_handle;
57 static guid_t lps0_dsm_guid;
58 static int lps0_dsm_func_mask;
59
60 static guid_t lps0_dsm_guid_microsoft;
61 static int lps0_dsm_func_mask_microsoft;
62 static int lps0_dsm_state;
63
64 /* Device constraint entry structure */
65 struct lpi_device_info {
66         char *name;
67         int enabled;
68         union acpi_object *package;
69 };
70
71 /* Constraint package structure */
72 struct lpi_device_constraint {
73         int uid;
74         int min_dstate;
75         int function_states;
76 };
77
78 struct lpi_constraints {
79         acpi_handle handle;
80         int min_dstate;
81 };
82
83 /* AMD Constraint package structure */
84 struct lpi_device_constraint_amd {
85         char *name;
86         int enabled;
87         int function_states;
88         int min_dstate;
89 };
90
91 static LIST_HEAD(lps0_s2idle_devops_head);
92
93 static struct lpi_constraints *lpi_constraints_table;
94 static int lpi_constraints_table_size;
95 static 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
102 static 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(lps0_device_handle, &lps0_dsm_guid,
108                                           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, dev_info.name, &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
188 free_acpi_buffer:
189         ACPI_FREE(out_obj);
190 }
191
192 static void lpi_device_get_constraints(void)
193 {
194         union acpi_object *out_obj;
195         int i;
196
197         out_obj = acpi_evaluate_dsm_typed(lps0_device_handle, &lps0_dsm_guid,
198                                           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, info.name, &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
298 free_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  */
314 int 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
326 static 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(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
355 static bool acpi_s2idle_vendor_amd(void)
356 {
357         return boot_cpu_data.x86_vendor == X86_VENDOR_AMD;
358 }
359
360 static 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
393 static 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(lps0_device_handle, &dsm_guid,
401                                         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
414 static 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, dsm_guid);
420
421         /* Check if the _DSM is present and as expected. */
422         obj = acpi_evaluate_dsm_typed(handle, dsm_guid, rev, 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
432 out:
433         ACPI_FREE(obj);
434         return ret;
435 }
436
437 struct amd_lps0_hid_device_data {
438         const bool check_off_by_one;
439 };
440
441 static const struct amd_lps0_hid_device_data amd_picasso = {
442         .check_off_by_one = true,
443 };
444
445 static const struct amd_lps0_hid_device_data amd_cezanne = {
446         .check_off_by_one = false,
447 };
448
449 static const struct acpi_device_id amd_hid_ids[] = {
450         {"AMD0004",     (kernel_ulong_t)&amd_picasso,   },
451         {"AMD0005",     (kernel_ulong_t)&amd_picasso,   },
452         {"AMDI0005",    (kernel_ulong_t)&amd_picasso,   },
453         {"AMDI0006",    (kernel_ulong_t)&amd_cezanne,   },
454         {}
455 };
456
457 static 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(adev->handle,
464                                                     ACPI_LPS0_DSM_UUID_MICROSOFT, 0,
465                                                     &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(adev->handle,
478                                         ACPI_LPS0_DSM_UUID_AMD, rev_id, &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(adev->handle,
490                                         ACPI_LPS0_DSM_UUID, rev_id, &lps0_dsm_guid);
491                 lps0_dsm_func_mask_microsoft = -EINVAL;
492         }
493
494         if (lps0_dsm_func_mask < 0 && lps0_dsm_func_mask_microsoft < 0)
495                 return 0; //function evaluation failed
496
497         lps0_device_handle = adev->handle;
498
499         if (acpi_s2idle_vendor_amd())
500                 lpi_device_get_constraints_amd();
501         else
502                 lpi_device_get_constraints();
503
504         /*
505          * Use suspend-to-idle by default if ACPI_FADT_LOW_POWER_S0 is set in
506          * the FADT and the default suspend mode was not set from the command
507          * line.
508          */
509         if ((acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0) &&
510             mem_sleep_default > PM_SUSPEND_MEM && !acpi_sleep_default_s3) {
511                 mem_sleep_current = PM_SUSPEND_TO_IDLE;
512                 pr_info("Low-power S0 idle used by default for system suspend\n");
513         }
514
515         /*
516          * Some LPS0 systems, like ASUS Zenbook UX430UNR/i7-8550U, require the
517          * EC GPE to be enabled while suspended for certain wakeup devices to
518          * work, so mark it as wakeup-capable.
519          */
520         acpi_ec_mark_gpe_for_wake();
521
522         return 0;
523 }
524
525 static struct acpi_scan_handler lps0_handler = {
526         .ids = lps0_device_ids,
527         .attach = lps0_device_attach,
528 };
529
530 int acpi_s2idle_prepare_late(void)
531 {
532         struct acpi_s2idle_dev_ops *handler;
533
534         if (!lps0_device_handle || sleep_no_lps0)
535                 return 0;
536
537         if (pm_debug_messages_on)
538                 lpi_check_constraints();
539
540         /* Screen off */
541         if (lps0_dsm_func_mask > 0)
542                 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
543                                         ACPI_LPS0_SCREEN_OFF_AMD :
544                                         ACPI_LPS0_SCREEN_OFF,
545                                         lps0_dsm_func_mask, lps0_dsm_guid);
546
547         if (lps0_dsm_func_mask_microsoft > 0)
548                 acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF,
549                                 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
550
551         /* LPS0 entry */
552         if (lps0_dsm_func_mask > 0)
553                 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
554                                         ACPI_LPS0_ENTRY_AMD :
555                                         ACPI_LPS0_ENTRY,
556                                         lps0_dsm_func_mask, lps0_dsm_guid);
557         if (lps0_dsm_func_mask_microsoft > 0) {
558                 /* modern standby entry */
559                 acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_ENTRY,
560                                 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
561                 acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY,
562                                 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
563         }
564
565         list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) {
566                 if (handler->prepare)
567                         handler->prepare();
568         }
569
570         return 0;
571 }
572
573 void acpi_s2idle_check(void)
574 {
575         struct acpi_s2idle_dev_ops *handler;
576
577         if (!lps0_device_handle || sleep_no_lps0)
578                 return;
579
580         list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) {
581                 if (handler->check)
582                         handler->check();
583         }
584 }
585
586 void acpi_s2idle_restore_early(void)
587 {
588         struct acpi_s2idle_dev_ops *handler;
589
590         if (!lps0_device_handle || sleep_no_lps0)
591                 return;
592
593         list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node)
594                 if (handler->restore)
595                         handler->restore();
596
597         /* LPS0 exit */
598         if (lps0_dsm_func_mask > 0)
599                 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
600                                         ACPI_LPS0_EXIT_AMD :
601                                         ACPI_LPS0_EXIT,
602                                         lps0_dsm_func_mask, lps0_dsm_guid);
603         if (lps0_dsm_func_mask_microsoft > 0)
604                 acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT,
605                                 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
606
607         /* Modern standby exit */
608         if (lps0_dsm_func_mask_microsoft > 0)
609                 acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_EXIT,
610                                 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
611
612         /* Screen on */
613         if (lps0_dsm_func_mask_microsoft > 0)
614                 acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON,
615                                 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
616         if (lps0_dsm_func_mask > 0)
617                 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
618                                         ACPI_LPS0_SCREEN_ON_AMD :
619                                         ACPI_LPS0_SCREEN_ON,
620                                         lps0_dsm_func_mask, lps0_dsm_guid);
621 }
622
623 static const struct platform_s2idle_ops acpi_s2idle_ops_lps0 = {
624         .begin = acpi_s2idle_begin,
625         .prepare = acpi_s2idle_prepare,
626         .prepare_late = acpi_s2idle_prepare_late,
627         .check = acpi_s2idle_check,
628         .wake = acpi_s2idle_wake,
629         .restore_early = acpi_s2idle_restore_early,
630         .restore = acpi_s2idle_restore,
631         .end = acpi_s2idle_end,
632 };
633
634 void __init acpi_s2idle_setup(void)
635 {
636         acpi_scan_add_handler(&lps0_handler);
637         s2idle_set_ops(&acpi_s2idle_ops_lps0);
638 }
639
640 int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg)
641 {
642         unsigned int sleep_flags;
643
644         if (!lps0_device_handle || sleep_no_lps0)
645                 return -ENODEV;
646
647         sleep_flags = lock_system_sleep();
648         list_add(&arg->list_node, &lps0_s2idle_devops_head);
649         unlock_system_sleep(sleep_flags);
650
651         return 0;
652 }
653 EXPORT_SYMBOL_GPL(acpi_register_lps0_dev);
654
655 void acpi_unregister_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;
661
662         sleep_flags = lock_system_sleep();
663         list_del(&arg->list_node);
664         unlock_system_sleep(sleep_flags);
665 }
666 EXPORT_SYMBOL_GPL(acpi_unregister_lps0_dev);
667
668 #endif /* CONFIG_SUSPEND */