1 // SPDX-License-Identifier: GPL-2.0-only
3  * kernel/power/suspend.c - Suspend to RAM and standby functionality.
65  * pm_suspend_default_s2idle - Check if suspend-to-idle is the default suspend.
67  * Return 'true' if suspend-to-idle has been selected as the default system
68  * suspend method.
128 	pm_pr_dbg("suspend-to-idle\n");  in s2idle_loop()
131 	 * Suspend-to-idle equals:  in s2idle_loop()
140 		if (s2idle_ops && s2idle_ops->wake) {  in s2idle_loop()
141 			if (s2idle_ops->wake())  in s2idle_loop()
147 		if (s2idle_ops && s2idle_ops->check)  in s2idle_loop()
148 			s2idle_ops->check();  in s2idle_loop()
153 	pm_pr_dbg("resume from suspend-to-idle\n");  in s2idle_loop()
172 	 * The PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states require low-level  in valid_state()
173 	 * support and need to be valid to the low-level implementation.  in valid_state()
175 	 * No ->valid() or ->enter() callback implies that none are valid.  in valid_state()
177 	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state) &&  in valid_state()
178 		suspend_ops->enter;  in valid_state()
187 	 * Suspend-to-idle should be supported even without any suspend_ops,  in pm_states_init()
210  * suspend_set_ops - Set the global suspend method table.
238  * suspend_valid_only_mem - Generic memory-only valid callback.
259 	return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?  in platform_suspend_prepare()
260 		suspend_ops->prepare() : 0;  in platform_suspend_prepare()
265 	return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?  in platform_suspend_prepare_late()
266 		s2idle_ops->prepare() : 0;  in platform_suspend_prepare_late()
272 		return s2idle_ops && s2idle_ops->prepare_late ?  in platform_suspend_prepare_noirq()
273 			s2idle_ops->prepare_late() : 0;  in platform_suspend_prepare_noirq()
275 	return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0;  in platform_suspend_prepare_noirq()
281 		if (s2idle_ops && s2idle_ops->restore_early)  in platform_resume_noirq()
282 			s2idle_ops->restore_early();  in platform_resume_noirq()
283 	} else if (suspend_ops->wake) {  in platform_resume_noirq()
284 		suspend_ops->wake();  in platform_resume_noirq()
290 	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore)  in platform_resume_early()
291 		s2idle_ops->restore();  in platform_resume_early()
296 	if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish)  in platform_resume_finish()
297 		suspend_ops->finish();  in platform_resume_finish()
302 	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin)  in platform_suspend_begin()
303 		return s2idle_ops->begin();  in platform_suspend_begin()
304 	else if (suspend_ops && suspend_ops->begin)  in platform_suspend_begin()
305 		return suspend_ops->begin(state);  in platform_suspend_begin()
312 	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end)  in platform_resume_end()
313 		s2idle_ops->end();  in platform_resume_end()
314 	else if (suspend_ops && suspend_ops->end)  in platform_resume_end()
315 		suspend_ops->end();  in platform_resume_end()
320 	if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)  in platform_recover()
321 		suspend_ops->recover();  in platform_recover()
326 	return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ?  in platform_suspend_again()
327 		suspend_ops->suspend_again() : false;  in platform_suspend_again()
351  * suspend_prepare - Prepare for entering system sleep state.
363 		return -EPERM;  in suspend_prepare()
397  * suspend_enter - Make the system enter the given sleep state.
399  * @wakeup: Returns information that the sleep state should not be re-entered.
403 static int suspend_enter(suspend_state_t state, bool *wakeup)  in suspend_enter()  argument
448 		*wakeup = pm_wakeup_pending();  in suspend_enter()
449 		if (!(suspend_test(TEST_CORE) || *wakeup)) {  in suspend_enter()
452 			error = suspend_ops->enter(state);  in suspend_enter()
455 		} else if (*wakeup) {  in suspend_enter()
456 			error = -EBUSY;  in suspend_enter()
485  * suspend_devices_and_enter - Suspend devices and enter system sleep state.
491 	bool wakeup = false;  in suspend_devices_and_enter()  local
494 		return -ENOSYS;  in suspend_devices_and_enter()
517 		error = suspend_enter(state, &wakeup);  in suspend_devices_and_enter()
518 	} while (!error && !wakeup && platform_suspend_again(state));  in suspend_devices_and_enter()
539  * suspend_finish - Clean up before finishing the suspend sequence.
552  * enter_state - Do common work needed to enter system sleep state.
557  * system enter the given sleep state and clean up after wakeup.
568 			return -EAGAIN;  in enter_state()
572 		return -EINVAL;  in enter_state()
575 		return -EBUSY;  in enter_state()
603 	pm_pr_dbg("Finishing wakeup.\n");  in enter_state()
611  * pm_suspend - Externally visible function for suspending the system.
622 		return -EINVAL;  in pm_suspend()