1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2/******************************************************************************
3 *
4 * Name: hwsleep.c - ACPI Hardware Sleep/Wake Support functions for the
5 * original/legacy sleep/PM registers.
6 *
7 * Copyright (C) 2000 - 2025, Intel Corp.
8 *
9 *****************************************************************************/
10
11#include <acpi/acpi.h>
12#include "accommon.h"
13
14#define _COMPONENT ACPI_HARDWARE
15ACPI_MODULE_NAME("hwsleep")
16
17#if (!ACPI_REDUCED_HARDWARE) /* Entire module */
18/*******************************************************************************
19 *
20 * FUNCTION: acpi_hw_legacy_sleep
21 *
22 * PARAMETERS: sleep_state - Which sleep state to enter
23 *
24 * RETURN: Status
25 *
26 * DESCRIPTION: Enter a system sleep state via the legacy FADT PM registers
27 * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
28 *
29 ******************************************************************************/
30acpi_status acpi_hw_legacy_sleep(u8 sleep_state)
31{
32 struct acpi_bit_register_info *sleep_type_reg_info;
33 struct acpi_bit_register_info *sleep_enable_reg_info;
34 u32 pm1a_control;
35 u32 pm1b_control;
36 u32 in_value;
37 acpi_status status;
38
39 ACPI_FUNCTION_TRACE(hw_legacy_sleep);
40
41 sleep_type_reg_info =
42 acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
43 sleep_enable_reg_info =
44 acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
45
46 /* Clear wake status */
47
48 status = acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS,
49 ACPI_CLEAR_STATUS);
50 if (ACPI_FAILURE(status)) {
51 return_ACPI_STATUS(status);
52 }
53
54 /* Disable all GPEs */
55 status = acpi_hw_disable_all_gpes();
56 if (ACPI_FAILURE(status)) {
57 return_ACPI_STATUS(status);
58 }
59 status = acpi_hw_clear_acpi_status();
60 if (ACPI_FAILURE(status)) {
61 return_ACPI_STATUS(status);
62 }
63 acpi_gbl_system_awake_and_running = FALSE;
64
65 /* Enable all wakeup GPEs */
66 status = acpi_hw_enable_all_wakeup_gpes();
67 if (ACPI_FAILURE(status)) {
68 return_ACPI_STATUS(status);
69 }
70
71 /* Get current value of PM1A control */
72
73 status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
74 return_value: &pm1a_control);
75 if (ACPI_FAILURE(status)) {
76 return_ACPI_STATUS(status);
77 }
78 ACPI_DEBUG_PRINT((ACPI_DB_INIT,
79 "Entering sleep state [S%u]\n", sleep_state));
80
81 /* Clear the SLP_EN and SLP_TYP fields */
82
83 pm1a_control &= ~(sleep_type_reg_info->access_bit_mask |
84 sleep_enable_reg_info->access_bit_mask);
85 pm1b_control = pm1a_control;
86
87 /* Insert the SLP_TYP bits */
88
89 pm1a_control |=
90 (acpi_gbl_sleep_type_a << sleep_type_reg_info->bit_position);
91 pm1b_control |=
92 (acpi_gbl_sleep_type_b << sleep_type_reg_info->bit_position);
93
94 /*
95 * We split the writes of SLP_TYP and SLP_EN to workaround
96 * poorly implemented hardware.
97 */
98
99 /* Write #1: write the SLP_TYP data to the PM1 Control registers */
100
101 status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
102 if (ACPI_FAILURE(status)) {
103 return_ACPI_STATUS(status);
104 }
105
106 /* Insert the sleep enable (SLP_EN) bit */
107
108 pm1a_control |= sleep_enable_reg_info->access_bit_mask;
109 pm1b_control |= sleep_enable_reg_info->access_bit_mask;
110
111 /* Flush caches, as per ACPI specification */
112
113 if (sleep_state < ACPI_STATE_S4) {
114 ACPI_FLUSH_CPU_CACHE();
115 }
116
117 status = acpi_os_enter_sleep(sleep_state, rega_value: pm1a_control, regb_value: pm1b_control);
118 if (status == AE_CTRL_TERMINATE) {
119 return_ACPI_STATUS(AE_OK);
120 }
121 if (ACPI_FAILURE(status)) {
122 return_ACPI_STATUS(status);
123 }
124
125 /* Write #2: Write both SLP_TYP + SLP_EN */
126
127 status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
128 if (ACPI_FAILURE(status)) {
129 return_ACPI_STATUS(status);
130 }
131
132 if (sleep_state > ACPI_STATE_S3) {
133 /*
134 * We wanted to sleep > S3, but it didn't happen (by virtue of the
135 * fact that we are still executing!)
136 *
137 * Wait ten seconds, then try again. This is to get S4/S5 to work on
138 * all machines.
139 *
140 * We wait so long to allow chipsets that poll this reg very slowly
141 * to still read the right value. Ideally, this block would go
142 * away entirely.
143 */
144 acpi_os_stall(microseconds: 10 * ACPI_USEC_PER_SEC);
145
146 status = acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL,
147 value: sleep_enable_reg_info->
148 access_bit_mask);
149 if (ACPI_FAILURE(status)) {
150 return_ACPI_STATUS(status);
151 }
152 }
153
154 /* Wait for transition back to Working State */
155
156 do {
157 status =
158 acpi_read_bit_register(ACPI_BITREG_WAKE_STATUS, return_value: &in_value);
159 if (ACPI_FAILURE(status)) {
160 return_ACPI_STATUS(status);
161 }
162
163 } while (!in_value);
164
165 return_ACPI_STATUS(AE_OK);
166}
167
168/*******************************************************************************
169 *
170 * FUNCTION: acpi_hw_legacy_wake_prep
171 *
172 * PARAMETERS: sleep_state - Which sleep state we just exited
173 *
174 * RETURN: Status
175 *
176 * DESCRIPTION: Perform the first state of OS-independent ACPI cleanup after a
177 * sleep.
178 * Called with interrupts ENABLED.
179 *
180 ******************************************************************************/
181
182acpi_status acpi_hw_legacy_wake_prep(u8 sleep_state)
183{
184 acpi_status status = AE_OK;
185 struct acpi_bit_register_info *sleep_type_reg_info;
186 struct acpi_bit_register_info *sleep_enable_reg_info;
187 u32 pm1a_control;
188 u32 pm1b_control;
189
190 ACPI_FUNCTION_TRACE(hw_legacy_wake_prep);
191
192 /*
193 * Set SLP_TYPE and SLP_EN to state S0.
194 * This is unclear from the ACPI Spec, but it is required
195 * by some machines.
196 */
197 if (acpi_gbl_sleep_type_a_s0 != ACPI_SLEEP_TYPE_INVALID) {
198 sleep_type_reg_info =
199 acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
200 sleep_enable_reg_info =
201 acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
202
203 /* Get current value of PM1A control */
204
205 status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
206 return_value: &pm1a_control);
207 if (ACPI_SUCCESS(status)) {
208
209 /* Clear the SLP_EN and SLP_TYP fields */
210
211 pm1a_control &= ~(sleep_type_reg_info->access_bit_mask |
212 sleep_enable_reg_info->
213 access_bit_mask);
214 pm1b_control = pm1a_control;
215
216 /* Insert the SLP_TYP bits */
217
218 pm1a_control |= (acpi_gbl_sleep_type_a_s0 <<
219 sleep_type_reg_info->bit_position);
220 pm1b_control |= (acpi_gbl_sleep_type_b_s0 <<
221 sleep_type_reg_info->bit_position);
222
223 /* Write the control registers and ignore any errors */
224
225 (void)acpi_hw_write_pm1_control(pm1a_control,
226 pm1b_control);
227 }
228 }
229
230 return_ACPI_STATUS(status);
231}
232
233/*******************************************************************************
234 *
235 * FUNCTION: acpi_hw_legacy_wake
236 *
237 * PARAMETERS: sleep_state - Which sleep state we just exited
238 *
239 * RETURN: Status
240 *
241 * DESCRIPTION: Perform OS-independent ACPI cleanup after a sleep
242 * Called with interrupts ENABLED.
243 *
244 ******************************************************************************/
245
246acpi_status acpi_hw_legacy_wake(u8 sleep_state)
247{
248 acpi_status status;
249
250 ACPI_FUNCTION_TRACE(hw_legacy_wake);
251
252 /* Ensure enter_sleep_state_prep -> enter_sleep_state ordering */
253
254 acpi_gbl_sleep_type_a = ACPI_SLEEP_TYPE_INVALID;
255 acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WAKING);
256
257 /*
258 * GPEs must be enabled before _WAK is called as GPEs
259 * might get fired there
260 *
261 * Restore the GPEs:
262 * 1) Disable all GPEs
263 * 2) Enable all runtime GPEs
264 */
265 status = acpi_hw_disable_all_gpes();
266 if (ACPI_FAILURE(status)) {
267 return_ACPI_STATUS(status);
268 }
269
270 status = acpi_hw_enable_all_runtime_gpes();
271 if (ACPI_FAILURE(status)) {
272 return_ACPI_STATUS(status);
273 }
274
275 /*
276 * Now we can execute _WAK, etc. Some machines require that the GPEs
277 * are enabled before the wake methods are executed.
278 */
279 acpi_hw_execute_sleep_method(METHOD_PATHNAME__WAK, integer_argument: sleep_state);
280
281 /*
282 * Some BIOS code assumes that WAK_STS will be cleared on resume
283 * and use it to determine whether the system is rebooting or
284 * resuming. Clear WAK_STS for compatibility.
285 */
286 (void)acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS,
287 ACPI_CLEAR_STATUS);
288 acpi_gbl_system_awake_and_running = TRUE;
289
290 /* Enable power button */
291
292 (void)
293 acpi_write_bit_register(register_id: acpi_gbl_fixed_event_info
294 [ACPI_EVENT_POWER_BUTTON].
295 enable_register_id, ACPI_ENABLE_EVENT);
296
297 (void)
298 acpi_write_bit_register(register_id: acpi_gbl_fixed_event_info
299 [ACPI_EVENT_POWER_BUTTON].
300 status_register_id, ACPI_CLEAR_STATUS);
301
302 /* Enable sleep button */
303
304 (void)
305 acpi_write_bit_register(register_id: acpi_gbl_fixed_event_info
306 [ACPI_EVENT_SLEEP_BUTTON].
307 enable_register_id, ACPI_ENABLE_EVENT);
308
309 (void)
310 acpi_write_bit_register(register_id: acpi_gbl_fixed_event_info
311 [ACPI_EVENT_SLEEP_BUTTON].
312 status_register_id, ACPI_CLEAR_STATUS);
313
314 acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WORKING);
315 return_ACPI_STATUS(status);
316}
317
318#endif /* !ACPI_REDUCED_HARDWARE */
319