xref: /openbmc/linux/drivers/acpi/acpica/hwsleep.c (revision 08193d1a)
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 	/* Disable all GPEs */
55 	status = acpi_hw_disable_all_gpes();
56 	if (ACPI_FAILURE(status)) {
57 		return_ACPI_STATUS(status);
58 	}
59 	/*
60 	 * If the target sleep state is S5, clear all GPEs and fixed events too
61 	 */
62 	if (sleep_state == ACPI_STATE_S5) {
63 		status = acpi_hw_clear_acpi_status();
64 		if (ACPI_FAILURE(status)) {
65 			return_ACPI_STATUS(status);
66 		}
67 	}
68 	acpi_gbl_system_awake_and_running = FALSE;
69 
70 	 /* Enable all wakeup GPEs */
71 	status = acpi_hw_enable_all_wakeup_gpes();
72 	if (ACPI_FAILURE(status)) {
73 		return_ACPI_STATUS(status);
74 	}
75 
76 	/* Get current value of PM1A control */
77 
78 	status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
79 				       &pm1a_control);
80 	if (ACPI_FAILURE(status)) {
81 		return_ACPI_STATUS(status);
82 	}
83 	ACPI_DEBUG_PRINT((ACPI_DB_INIT,
84 			  "Entering sleep state [S%u]\n", sleep_state));
85 
86 	/* Clear the SLP_EN and SLP_TYP fields */
87 
88 	pm1a_control &= ~(sleep_type_reg_info->access_bit_mask |
89 			  sleep_enable_reg_info->access_bit_mask);
90 	pm1b_control = pm1a_control;
91 
92 	/* Insert the SLP_TYP bits */
93 
94 	pm1a_control |=
95 	    (acpi_gbl_sleep_type_a << sleep_type_reg_info->bit_position);
96 	pm1b_control |=
97 	    (acpi_gbl_sleep_type_b << sleep_type_reg_info->bit_position);
98 
99 	/*
100 	 * We split the writes of SLP_TYP and SLP_EN to workaround
101 	 * poorly implemented hardware.
102 	 */
103 
104 	/* Write #1: write the SLP_TYP data to the PM1 Control registers */
105 
106 	status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
107 	if (ACPI_FAILURE(status)) {
108 		return_ACPI_STATUS(status);
109 	}
110 
111 	/* Insert the sleep enable (SLP_EN) bit */
112 
113 	pm1a_control |= sleep_enable_reg_info->access_bit_mask;
114 	pm1b_control |= sleep_enable_reg_info->access_bit_mask;
115 
116 	/* Flush caches, as per ACPI specification */
117 
118 	ACPI_FLUSH_CPU_CACHE();
119 
120 	status = acpi_os_enter_sleep(sleep_state, pm1a_control, pm1b_control);
121 	if (status == AE_CTRL_TERMINATE) {
122 		return_ACPI_STATUS(AE_OK);
123 	}
124 	if (ACPI_FAILURE(status)) {
125 		return_ACPI_STATUS(status);
126 	}
127 
128 	/* Write #2: Write both SLP_TYP + SLP_EN */
129 
130 	status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
131 	if (ACPI_FAILURE(status)) {
132 		return_ACPI_STATUS(status);
133 	}
134 
135 	if (sleep_state > ACPI_STATE_S3) {
136 		/*
137 		 * We wanted to sleep > S3, but it didn't happen (by virtue of the
138 		 * fact that we are still executing!)
139 		 *
140 		 * Wait ten seconds, then try again. This is to get S4/S5 to work on
141 		 * all machines.
142 		 *
143 		 * We wait so long to allow chipsets that poll this reg very slowly
144 		 * to still read the right value. Ideally, this block would go
145 		 * away entirely.
146 		 */
147 		acpi_os_stall(10 * ACPI_USEC_PER_SEC);
148 
149 		status = acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL,
150 						sleep_enable_reg_info->
151 						access_bit_mask);
152 		if (ACPI_FAILURE(status)) {
153 			return_ACPI_STATUS(status);
154 		}
155 	}
156 
157 	/* Wait for transition back to Working State */
158 
159 	do {
160 		status =
161 		    acpi_read_bit_register(ACPI_BITREG_WAKE_STATUS, &in_value);
162 		if (ACPI_FAILURE(status)) {
163 			return_ACPI_STATUS(status);
164 		}
165 
166 	} while (!in_value);
167 
168 	return_ACPI_STATUS(AE_OK);
169 }
170 
171 /*******************************************************************************
172  *
173  * FUNCTION:    acpi_hw_legacy_wake_prep
174  *
175  * PARAMETERS:  sleep_state         - Which sleep state we just exited
176  *
177  * RETURN:      Status
178  *
179  * DESCRIPTION: Perform the first state of OS-independent ACPI cleanup after a
180  *              sleep.
181  *              Called with interrupts ENABLED.
182  *
183  ******************************************************************************/
184 
185 acpi_status acpi_hw_legacy_wake_prep(u8 sleep_state)
186 {
187 	acpi_status status;
188 	struct acpi_bit_register_info *sleep_type_reg_info;
189 	struct acpi_bit_register_info *sleep_enable_reg_info;
190 	u32 pm1a_control;
191 	u32 pm1b_control;
192 
193 	ACPI_FUNCTION_TRACE(hw_legacy_wake_prep);
194 
195 	/*
196 	 * Set SLP_TYPE and SLP_EN to state S0.
197 	 * This is unclear from the ACPI Spec, but it is required
198 	 * by some machines.
199 	 */
200 	status = acpi_get_sleep_type_data(ACPI_STATE_S0,
201 					  &acpi_gbl_sleep_type_a,
202 					  &acpi_gbl_sleep_type_b);
203 	if (ACPI_SUCCESS(status)) {
204 		sleep_type_reg_info =
205 		    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
206 		sleep_enable_reg_info =
207 		    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
208 
209 		/* Get current value of PM1A control */
210 
211 		status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
212 					       &pm1a_control);
213 		if (ACPI_SUCCESS(status)) {
214 
215 			/* Clear the SLP_EN and SLP_TYP fields */
216 
217 			pm1a_control &= ~(sleep_type_reg_info->access_bit_mask |
218 					  sleep_enable_reg_info->
219 					  access_bit_mask);
220 			pm1b_control = pm1a_control;
221 
222 			/* Insert the SLP_TYP bits */
223 
224 			pm1a_control |= (acpi_gbl_sleep_type_a <<
225 					 sleep_type_reg_info->bit_position);
226 			pm1b_control |= (acpi_gbl_sleep_type_b <<
227 					 sleep_type_reg_info->bit_position);
228 
229 			/* Write the control registers and ignore any errors */
230 
231 			(void)acpi_hw_write_pm1_control(pm1a_control,
232 							pm1b_control);
233 		}
234 	}
235 
236 	return_ACPI_STATUS(status);
237 }
238 
239 /*******************************************************************************
240  *
241  * FUNCTION:    acpi_hw_legacy_wake
242  *
243  * PARAMETERS:  sleep_state         - Which sleep state we just exited
244  *
245  * RETURN:      Status
246  *
247  * DESCRIPTION: Perform OS-independent ACPI cleanup after a sleep
248  *              Called with interrupts ENABLED.
249  *
250  ******************************************************************************/
251 
252 acpi_status acpi_hw_legacy_wake(u8 sleep_state)
253 {
254 	acpi_status status;
255 
256 	ACPI_FUNCTION_TRACE(hw_legacy_wake);
257 
258 	/* Ensure enter_sleep_state_prep -> enter_sleep_state ordering */
259 
260 	acpi_gbl_sleep_type_a = ACPI_SLEEP_TYPE_INVALID;
261 	acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WAKING);
262 
263 	/*
264 	 * GPEs must be enabled before _WAK is called as GPEs
265 	 * might get fired there
266 	 *
267 	 * Restore the GPEs:
268 	 * 1) Disable all GPEs
269 	 * 2) Enable all runtime GPEs
270 	 */
271 	status = acpi_hw_disable_all_gpes();
272 	if (ACPI_FAILURE(status)) {
273 		return_ACPI_STATUS(status);
274 	}
275 
276 	status = acpi_hw_enable_all_runtime_gpes();
277 	if (ACPI_FAILURE(status)) {
278 		return_ACPI_STATUS(status);
279 	}
280 
281 	/*
282 	 * Now we can execute _WAK, etc. Some machines require that the GPEs
283 	 * are enabled before the wake methods are executed.
284 	 */
285 	acpi_hw_execute_sleep_method(METHOD_PATHNAME__WAK, sleep_state);
286 
287 	/*
288 	 * Some BIOS code assumes that WAK_STS will be cleared on resume
289 	 * and use it to determine whether the system is rebooting or
290 	 * resuming. Clear WAK_STS for compatibility.
291 	 */
292 	(void)acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS,
293 				      ACPI_CLEAR_STATUS);
294 	acpi_gbl_system_awake_and_running = TRUE;
295 
296 	/* Enable power button */
297 
298 	(void)
299 	    acpi_write_bit_register(acpi_gbl_fixed_event_info
300 				    [ACPI_EVENT_POWER_BUTTON].
301 				    enable_register_id, ACPI_ENABLE_EVENT);
302 
303 	(void)
304 	    acpi_write_bit_register(acpi_gbl_fixed_event_info
305 				    [ACPI_EVENT_POWER_BUTTON].
306 				    status_register_id, ACPI_CLEAR_STATUS);
307 
308 	acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WORKING);
309 	return_ACPI_STATUS(status);
310 }
311 
312 #endif				/* !ACPI_REDUCED_HARDWARE */
313