xref: /openbmc/linux/drivers/acpi/acpica/hwsleep.c (revision 8e41e0a5)
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 - 2023, Intel Corp.
8  *
9  *****************************************************************************/
10 
11 #include <acpi/acpi.h>
12 #include "accommon.h"
13 
14 #define _COMPONENT          ACPI_HARDWARE
15 ACPI_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  ******************************************************************************/
acpi_hw_legacy_sleep(u8 sleep_state)30 acpi_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 				       &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, pm1a_control, 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(10 * ACPI_USEC_PER_SEC);
145 
146 		status = acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL,
147 						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, &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 
acpi_hw_legacy_wake_prep(u8 sleep_state)182 acpi_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 					       &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 
acpi_hw_legacy_wake(u8 sleep_state)246 acpi_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, 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(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(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(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(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