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
lpi_device_get_constraints_amd(void)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
lpi_device_get_constraints(void)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 */
acpi_get_lps0_constraint(struct acpi_device * adev)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
lpi_check_constraints(void)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
acpi_s2idle_vendor_amd(void)355 static bool acpi_s2idle_vendor_amd(void)
356 {
357 return boot_cpu_data.x86_vendor == X86_VENDOR_AMD;
358 }
359
acpi_sleep_dsm_state_to_str(unsigned int state)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
acpi_sleep_run_lps0_dsm(unsigned int func,unsigned int func_mask,guid_t dsm_guid)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
validate_dsm(acpi_handle handle,const char * uuid,int rev,guid_t * dsm_guid)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 obj = acpi_evaluate_dsm(handle, dsm_guid, rev, 0, NULL);
421
422 /* Check if the _DSM is present and as expected. */
423 if (!obj || obj->type != ACPI_TYPE_BUFFER || obj->buffer.length == 0 ||
424 obj->buffer.length > sizeof(u32)) {
425 acpi_handle_debug(handle,
426 "_DSM UUID %s rev %d function 0 evaluation failed\n", uuid, rev);
427 goto out;
428 }
429
430 ret = *(int *)obj->buffer.pointer;
431 acpi_handle_debug(handle, "_DSM UUID %s rev %d function mask: 0x%x\n", uuid, rev, ret);
432
433 out:
434 ACPI_FREE(obj);
435 return ret;
436 }
437
438 struct amd_lps0_hid_device_data {
439 const bool check_off_by_one;
440 };
441
442 static const struct amd_lps0_hid_device_data amd_picasso = {
443 .check_off_by_one = true,
444 };
445
446 static const struct amd_lps0_hid_device_data amd_cezanne = {
447 .check_off_by_one = false,
448 };
449
450 static const struct acpi_device_id amd_hid_ids[] = {
451 {"AMD0004", (kernel_ulong_t)&amd_picasso, },
452 {"AMD0005", (kernel_ulong_t)&amd_picasso, },
453 {"AMDI0005", (kernel_ulong_t)&amd_picasso, },
454 {"AMDI0006", (kernel_ulong_t)&amd_cezanne, },
455 {}
456 };
457
lps0_device_attach(struct acpi_device * adev,const struct acpi_device_id * not_used)458 static int lps0_device_attach(struct acpi_device *adev,
459 const struct acpi_device_id *not_used)
460 {
461 if (lps0_device_handle)
462 return 0;
463
464 lps0_dsm_func_mask_microsoft = validate_dsm(adev->handle,
465 ACPI_LPS0_DSM_UUID_MICROSOFT, 0,
466 &lps0_dsm_guid_microsoft);
467 if (acpi_s2idle_vendor_amd()) {
468 static const struct acpi_device_id *dev_id;
469 const struct amd_lps0_hid_device_data *data;
470
471 for (dev_id = &amd_hid_ids[0]; dev_id->id[0]; dev_id++)
472 if (acpi_dev_hid_uid_match(adev, dev_id->id, NULL))
473 break;
474 if (dev_id->id[0])
475 data = (const struct amd_lps0_hid_device_data *) dev_id->driver_data;
476 else
477 data = &amd_cezanne;
478 lps0_dsm_func_mask = validate_dsm(adev->handle,
479 ACPI_LPS0_DSM_UUID_AMD, rev_id, &lps0_dsm_guid);
480 if (lps0_dsm_func_mask > 0x3 && data->check_off_by_one) {
481 lps0_dsm_func_mask = (lps0_dsm_func_mask << 1) | 0x1;
482 acpi_handle_debug(adev->handle, "_DSM UUID %s: Adjusted function mask: 0x%x\n",
483 ACPI_LPS0_DSM_UUID_AMD, lps0_dsm_func_mask);
484 } else if (lps0_dsm_func_mask_microsoft > 0 && rev_id) {
485 lps0_dsm_func_mask_microsoft = -EINVAL;
486 acpi_handle_debug(adev->handle, "_DSM Using AMD method\n");
487 }
488 } else {
489 rev_id = 1;
490 lps0_dsm_func_mask = validate_dsm(adev->handle,
491 ACPI_LPS0_DSM_UUID, rev_id, &lps0_dsm_guid);
492 lps0_dsm_func_mask_microsoft = -EINVAL;
493 }
494
495 if (lps0_dsm_func_mask < 0 && lps0_dsm_func_mask_microsoft < 0)
496 return 0; //function evaluation failed
497
498 lps0_device_handle = adev->handle;
499
500 if (acpi_s2idle_vendor_amd())
501 lpi_device_get_constraints_amd();
502 else
503 lpi_device_get_constraints();
504
505 /*
506 * Use suspend-to-idle by default if ACPI_FADT_LOW_POWER_S0 is set in
507 * the FADT and the default suspend mode was not set from the command
508 * line.
509 */
510 if ((acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0) &&
511 mem_sleep_default > PM_SUSPEND_MEM && !acpi_sleep_default_s3) {
512 mem_sleep_current = PM_SUSPEND_TO_IDLE;
513 pr_info("Low-power S0 idle used by default for system suspend\n");
514 }
515
516 /*
517 * Some LPS0 systems, like ASUS Zenbook UX430UNR/i7-8550U, require the
518 * EC GPE to be enabled while suspended for certain wakeup devices to
519 * work, so mark it as wakeup-capable.
520 */
521 acpi_ec_mark_gpe_for_wake();
522
523 return 0;
524 }
525
526 static struct acpi_scan_handler lps0_handler = {
527 .ids = lps0_device_ids,
528 .attach = lps0_device_attach,
529 };
530
acpi_s2idle_prepare_late(void)531 int acpi_s2idle_prepare_late(void)
532 {
533 struct acpi_s2idle_dev_ops *handler;
534
535 if (!lps0_device_handle || sleep_no_lps0)
536 return 0;
537
538 if (pm_debug_messages_on)
539 lpi_check_constraints();
540
541 /* Screen off */
542 if (lps0_dsm_func_mask > 0)
543 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
544 ACPI_LPS0_SCREEN_OFF_AMD :
545 ACPI_LPS0_SCREEN_OFF,
546 lps0_dsm_func_mask, lps0_dsm_guid);
547
548 if (lps0_dsm_func_mask_microsoft > 0)
549 acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF,
550 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
551
552 /* LPS0 entry */
553 if (lps0_dsm_func_mask > 0)
554 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
555 ACPI_LPS0_ENTRY_AMD :
556 ACPI_LPS0_ENTRY,
557 lps0_dsm_func_mask, lps0_dsm_guid);
558 if (lps0_dsm_func_mask_microsoft > 0) {
559 /* modern standby entry */
560 acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_ENTRY,
561 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
562 acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY,
563 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
564 }
565
566 list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) {
567 if (handler->prepare)
568 handler->prepare();
569 }
570
571 return 0;
572 }
573
acpi_s2idle_check(void)574 void acpi_s2idle_check(void)
575 {
576 struct acpi_s2idle_dev_ops *handler;
577
578 if (!lps0_device_handle || sleep_no_lps0)
579 return;
580
581 list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) {
582 if (handler->check)
583 handler->check();
584 }
585 }
586
acpi_s2idle_restore_early(void)587 void acpi_s2idle_restore_early(void)
588 {
589 struct acpi_s2idle_dev_ops *handler;
590
591 if (!lps0_device_handle || sleep_no_lps0)
592 return;
593
594 list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node)
595 if (handler->restore)
596 handler->restore();
597
598 /* LPS0 exit */
599 if (lps0_dsm_func_mask > 0)
600 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
601 ACPI_LPS0_EXIT_AMD :
602 ACPI_LPS0_EXIT,
603 lps0_dsm_func_mask, lps0_dsm_guid);
604 if (lps0_dsm_func_mask_microsoft > 0)
605 acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT,
606 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
607
608 /* Modern standby exit */
609 if (lps0_dsm_func_mask_microsoft > 0)
610 acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_EXIT,
611 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
612
613 /* Screen on */
614 if (lps0_dsm_func_mask_microsoft > 0)
615 acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON,
616 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
617 if (lps0_dsm_func_mask > 0)
618 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
619 ACPI_LPS0_SCREEN_ON_AMD :
620 ACPI_LPS0_SCREEN_ON,
621 lps0_dsm_func_mask, lps0_dsm_guid);
622 }
623
624 static const struct platform_s2idle_ops acpi_s2idle_ops_lps0 = {
625 .begin = acpi_s2idle_begin,
626 .prepare = acpi_s2idle_prepare,
627 .prepare_late = acpi_s2idle_prepare_late,
628 .check = acpi_s2idle_check,
629 .wake = acpi_s2idle_wake,
630 .restore_early = acpi_s2idle_restore_early,
631 .restore = acpi_s2idle_restore,
632 .end = acpi_s2idle_end,
633 };
634
acpi_s2idle_setup(void)635 void __init acpi_s2idle_setup(void)
636 {
637 acpi_scan_add_handler(&lps0_handler);
638 s2idle_set_ops(&acpi_s2idle_ops_lps0);
639 }
640
acpi_register_lps0_dev(struct acpi_s2idle_dev_ops * arg)641 int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg)
642 {
643 unsigned int sleep_flags;
644
645 if (!lps0_device_handle || sleep_no_lps0)
646 return -ENODEV;
647
648 sleep_flags = lock_system_sleep();
649 list_add(&arg->list_node, &lps0_s2idle_devops_head);
650 unlock_system_sleep(sleep_flags);
651
652 return 0;
653 }
654 EXPORT_SYMBOL_GPL(acpi_register_lps0_dev);
655
acpi_unregister_lps0_dev(struct acpi_s2idle_dev_ops * arg)656 void acpi_unregister_lps0_dev(struct acpi_s2idle_dev_ops *arg)
657 {
658 unsigned int sleep_flags;
659
660 if (!lps0_device_handle || sleep_no_lps0)
661 return;
662
663 sleep_flags = lock_system_sleep();
664 list_del(&arg->list_node);
665 unlock_system_sleep(sleep_flags);
666 }
667 EXPORT_SYMBOL_GPL(acpi_unregister_lps0_dev);
668
669 #endif /* CONFIG_SUSPEND */
670