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.
122 	pm_pr_dbg("suspend-to-idle\n");  in s2idle_loop()
125 	 * Suspend-to-idle equals:  in s2idle_loop()
134 		if (s2idle_ops && s2idle_ops->wake) {  in s2idle_loop()
135 			if (s2idle_ops->wake())  in s2idle_loop()
146 	pm_pr_dbg("resume from suspend-to-idle\n");  in s2idle_loop()
169 	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);  in valid_state()
178 	 * Suspend-to-idle should be supported even without any suspend_ops,  in pm_states_init()
200  * suspend_set_ops - Set the global suspend method table.
226  * suspend_valid_only_mem - Generic memory-only valid callback.
241 	return state == PM_SUSPEND_TO_IDLE || (suspend_ops && suspend_ops->enter);  in sleep_state_supported()
246 	return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?  in platform_suspend_prepare()
247 		suspend_ops->prepare() : 0;  in platform_suspend_prepare()
252 	return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?  in platform_suspend_prepare_late()
253 		s2idle_ops->prepare() : 0;  in platform_suspend_prepare_late()
259 		return s2idle_ops && s2idle_ops->prepare_late ?  in platform_suspend_prepare_noirq()
260 			s2idle_ops->prepare_late() : 0;  in platform_suspend_prepare_noirq()
262 	return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0;  in platform_suspend_prepare_noirq()
268 		if (s2idle_ops && s2idle_ops->restore_early)  in platform_resume_noirq()
269 			s2idle_ops->restore_early();  in platform_resume_noirq()
270 	} else if (suspend_ops->wake) {  in platform_resume_noirq()
271 		suspend_ops->wake();  in platform_resume_noirq()
277 	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore)  in platform_resume_early()
278 		s2idle_ops->restore();  in platform_resume_early()
283 	if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish)  in platform_resume_finish()
284 		suspend_ops->finish();  in platform_resume_finish()
289 	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin)  in platform_suspend_begin()
290 		return s2idle_ops->begin();  in platform_suspend_begin()
291 	else if (suspend_ops && suspend_ops->begin)  in platform_suspend_begin()
292 		return suspend_ops->begin(state);  in platform_suspend_begin()
299 	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end)  in platform_resume_end()
300 		s2idle_ops->end();  in platform_resume_end()
301 	else if (suspend_ops && suspend_ops->end)  in platform_resume_end()
302 		suspend_ops->end();  in platform_resume_end()
307 	if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)  in platform_recover()
308 		suspend_ops->recover();  in platform_recover()
313 	return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ?  in platform_suspend_again()
314 		suspend_ops->suspend_again() : false;  in platform_suspend_again()
338  * suspend_prepare - Prepare for entering system sleep state.
350 		return -EPERM;  in suspend_prepare()
385  * suspend_enter - Make the system enter the given sleep state.
387  * @wakeup: Returns information that the sleep state should not be re-entered.
391 static int suspend_enter(suspend_state_t state, bool *wakeup)  in suspend_enter()  argument
436 		*wakeup = pm_wakeup_pending();  in suspend_enter()
437 		if (!(suspend_test(TEST_CORE) || *wakeup)) {  in suspend_enter()
440 			error = suspend_ops->enter(state);  in suspend_enter()
443 		} else if (*wakeup) {  in suspend_enter()
444 			error = -EBUSY;  in suspend_enter()
473  * suspend_devices_and_enter - Suspend devices and enter system sleep state.
479 	bool wakeup = false;  in suspend_devices_and_enter()  local
482 		return -ENOSYS;  in suspend_devices_and_enter()
505 		error = suspend_enter(state, &wakeup);  in suspend_devices_and_enter()
506 	} while (!error && !wakeup && platform_suspend_again(state));  in suspend_devices_and_enter()
527  * suspend_finish - Clean up before finishing the suspend sequence.
540  * enter_state - Do common work needed to enter system sleep state.
545  * system enter the given sleep state and clean up after wakeup.
556 			return -EAGAIN;  in enter_state()
560 		return -EINVAL;  in enter_state()
563 		return -EBUSY;  in enter_state()
591 	pm_pr_dbg("Finishing wakeup.\n");  in enter_state()
599  * pm_suspend - Externally visible function for suspending the system.
610 		return -EINVAL;  in pm_suspend()