xref: /openbmc/linux/drivers/acpi/acpica/hwsleep.c (revision ba61bb17)
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 - 2018, 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  ******************************************************************************/
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 	/*
55 	 * 1) Disable all GPEs
56 	 * 2) Enable all wakeup GPEs
57 	 */
58 	status = acpi_hw_disable_all_gpes();
59 	if (ACPI_FAILURE(status)) {
60 		return_ACPI_STATUS(status);
61 	}
62 	acpi_gbl_system_awake_and_running = FALSE;
63 
64 	status = acpi_hw_enable_all_wakeup_gpes();
65 	if (ACPI_FAILURE(status)) {
66 		return_ACPI_STATUS(status);
67 	}
68 
69 	/* Get current value of PM1A control */
70 
71 	status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
72 				       &pm1a_control);
73 	if (ACPI_FAILURE(status)) {
74 		return_ACPI_STATUS(status);
75 	}
76 	ACPI_DEBUG_PRINT((ACPI_DB_INIT,
77 			  "Entering sleep state [S%u]\n", sleep_state));
78 
79 	/* Clear the SLP_EN and SLP_TYP fields */
80 
81 	pm1a_control &= ~(sleep_type_reg_info->access_bit_mask |
82 			  sleep_enable_reg_info->access_bit_mask);
83 	pm1b_control = pm1a_control;
84 
85 	/* Insert the SLP_TYP bits */
86 
87 	pm1a_control |=
88 	    (acpi_gbl_sleep_type_a << sleep_type_reg_info->bit_position);
89 	pm1b_control |=
90 	    (acpi_gbl_sleep_type_b << sleep_type_reg_info->bit_position);
91 
92 	/*
93 	 * We split the writes of SLP_TYP and SLP_EN to workaround
94 	 * poorly implemented hardware.
95 	 */
96 
97 	/* Write #1: write the SLP_TYP data to the PM1 Control registers */
98 
99 	status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
100 	if (ACPI_FAILURE(status)) {
101 		return_ACPI_STATUS(status);
102 	}
103 
104 	/* Insert the sleep enable (SLP_EN) bit */
105 
106 	pm1a_control |= sleep_enable_reg_info->access_bit_mask;
107 	pm1b_control |= sleep_enable_reg_info->access_bit_mask;
108 
109 	/* Flush caches, as per ACPI specification */
110 
111 	ACPI_FLUSH_CPU_CACHE();
112 
113 	status = acpi_os_enter_sleep(sleep_state, pm1a_control, pm1b_control);
114 	if (status == AE_CTRL_TERMINATE) {
115 		return_ACPI_STATUS(AE_OK);
116 	}
117 	if (ACPI_FAILURE(status)) {
118 		return_ACPI_STATUS(status);
119 	}
120 
121 	/* Write #2: Write both SLP_TYP + SLP_EN */
122 
123 	status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
124 	if (ACPI_FAILURE(status)) {
125 		return_ACPI_STATUS(status);
126 	}
127 
128 	if (sleep_state > ACPI_STATE_S3) {
129 		/*
130 		 * We wanted to sleep > S3, but it didn't happen (by virtue of the
131 		 * fact that we are still executing!)
132 		 *
133 		 * Wait ten seconds, then try again. This is to get S4/S5 to work on
134 		 * all machines.
135 		 *
136 		 * We wait so long to allow chipsets that poll this reg very slowly
137 		 * to still read the right value. Ideally, this block would go
138 		 * away entirely.
139 		 */
140 		acpi_os_stall(10 * ACPI_USEC_PER_SEC);
141 
142 		status = acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL,
143 						sleep_enable_reg_info->
144 						access_bit_mask);
145 		if (ACPI_FAILURE(status)) {
146 			return_ACPI_STATUS(status);
147 		}
148 	}
149 
150 	/* Wait for transition back to Working State */
151 
152 	do {
153 		status =
154 		    acpi_read_bit_register(ACPI_BITREG_WAKE_STATUS, &in_value);
155 		if (ACPI_FAILURE(status)) {
156 			return_ACPI_STATUS(status);
157 		}
158 
159 	} while (!in_value);
160 
161 	return_ACPI_STATUS(AE_OK);
162 }
163 
164 /*******************************************************************************
165  *
166  * FUNCTION:    acpi_hw_legacy_wake_prep
167  *
168  * PARAMETERS:  sleep_state         - Which sleep state we just exited
169  *
170  * RETURN:      Status
171  *
172  * DESCRIPTION: Perform the first state of OS-independent ACPI cleanup after a
173  *              sleep.
174  *              Called with interrupts ENABLED.
175  *
176  ******************************************************************************/
177 
178 acpi_status acpi_hw_legacy_wake_prep(u8 sleep_state)
179 {
180 	acpi_status status;
181 	struct acpi_bit_register_info *sleep_type_reg_info;
182 	struct acpi_bit_register_info *sleep_enable_reg_info;
183 	u32 pm1a_control;
184 	u32 pm1b_control;
185 
186 	ACPI_FUNCTION_TRACE(hw_legacy_wake_prep);
187 
188 	/*
189 	 * Set SLP_TYPE and SLP_EN to state S0.
190 	 * This is unclear from the ACPI Spec, but it is required
191 	 * by some machines.
192 	 */
193 	status = acpi_get_sleep_type_data(ACPI_STATE_S0,
194 					  &acpi_gbl_sleep_type_a,
195 					  &acpi_gbl_sleep_type_b);
196 	if (ACPI_SUCCESS(status)) {
197 		sleep_type_reg_info =
198 		    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
199 		sleep_enable_reg_info =
200 		    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
201 
202 		/* Get current value of PM1A control */
203 
204 		status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
205 					       &pm1a_control);
206 		if (ACPI_SUCCESS(status)) {
207 
208 			/* Clear the SLP_EN and SLP_TYP fields */
209 
210 			pm1a_control &= ~(sleep_type_reg_info->access_bit_mask |
211 					  sleep_enable_reg_info->
212 					  access_bit_mask);
213 			pm1b_control = pm1a_control;
214 
215 			/* Insert the SLP_TYP bits */
216 
217 			pm1a_control |= (acpi_gbl_sleep_type_a <<
218 					 sleep_type_reg_info->bit_position);
219 			pm1b_control |= (acpi_gbl_sleep_type_b <<
220 					 sleep_type_reg_info->bit_position);
221 
222 			/* Write the control registers and ignore any errors */
223 
224 			(void)acpi_hw_write_pm1_control(pm1a_control,
225 							pm1b_control);
226 		}
227 	}
228 
229 	return_ACPI_STATUS(status);
230 }
231 
232 /*******************************************************************************
233  *
234  * FUNCTION:    acpi_hw_legacy_wake
235  *
236  * PARAMETERS:  sleep_state         - Which sleep state we just exited
237  *
238  * RETURN:      Status
239  *
240  * DESCRIPTION: Perform OS-independent ACPI cleanup after a sleep
241  *              Called with interrupts ENABLED.
242  *
243  ******************************************************************************/
244 
245 acpi_status acpi_hw_legacy_wake(u8 sleep_state)
246 {
247 	acpi_status status;
248 
249 	ACPI_FUNCTION_TRACE(hw_legacy_wake);
250 
251 	/* Ensure enter_sleep_state_prep -> enter_sleep_state ordering */
252 
253 	acpi_gbl_sleep_type_a = ACPI_SLEEP_TYPE_INVALID;
254 	acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WAKING);
255 
256 	/*
257 	 * GPEs must be enabled before _WAK is called as GPEs
258 	 * might get fired there
259 	 *
260 	 * Restore the GPEs:
261 	 * 1) Disable all GPEs
262 	 * 2) Enable all runtime GPEs
263 	 */
264 	status = acpi_hw_disable_all_gpes();
265 	if (ACPI_FAILURE(status)) {
266 		return_ACPI_STATUS(status);
267 	}
268 
269 	status = acpi_hw_enable_all_runtime_gpes();
270 	if (ACPI_FAILURE(status)) {
271 		return_ACPI_STATUS(status);
272 	}
273 
274 	/*
275 	 * Now we can execute _WAK, etc. Some machines require that the GPEs
276 	 * are enabled before the wake methods are executed.
277 	 */
278 	acpi_hw_execute_sleep_method(METHOD_PATHNAME__WAK, sleep_state);
279 
280 	/*
281 	 * Some BIOS code assumes that WAK_STS will be cleared on resume
282 	 * and use it to determine whether the system is rebooting or
283 	 * resuming. Clear WAK_STS for compatibility.
284 	 */
285 	(void)acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS,
286 				      ACPI_CLEAR_STATUS);
287 	acpi_gbl_system_awake_and_running = TRUE;
288 
289 	/* Enable power button */
290 
291 	(void)
292 	    acpi_write_bit_register(acpi_gbl_fixed_event_info
293 				    [ACPI_EVENT_POWER_BUTTON].
294 				    enable_register_id, ACPI_ENABLE_EVENT);
295 
296 	(void)
297 	    acpi_write_bit_register(acpi_gbl_fixed_event_info
298 				    [ACPI_EVENT_POWER_BUTTON].
299 				    status_register_id, ACPI_CLEAR_STATUS);
300 
301 	acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WORKING);
302 	return_ACPI_STATUS(status);
303 }
304 
305 #endif				/* !ACPI_REDUCED_HARDWARE */
306