[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / power / suspend.c

/*
 * kernel/power/suspend.c - Suspend to RAM and standby functionality.
 *
 * Copyright (c) 2003 Patrick Mochel
 * Copyright (c) 2003 Open Source Development Lab
 * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
 *
 * This file is released under the GPLv2.
 */

#include <linux/string.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/console.h>
#include <linux/cpu.h>
#include <linux/syscalls.h>
#include <linux/gfp.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/suspend.h>
#include <linux/syscore_ops.h>
#include <trace/events/power.h>

#include "power.h"

const char *const pm_states[PM_SUSPEND_MAX] = {
	[PM_SUSPEND_STANDBY]	= "standby",
	[PM_SUSPEND_MEM]	= "mem",
};

static const struct platform_suspend_ops *suspend_ops;

/**
 * suspend_set_ops - Set the global suspend method table.
 * @ops: Suspend operations to use.
 */
void suspend_set_ops(const struct platform_suspend_ops *ops)
{
	lock_system_sleep();
	suspend_ops = ops;
	unlock_system_sleep();
}
EXPORT_SYMBOL_GPL(suspend_set_ops);

bool valid_state(suspend_state_t state)
{
	/*
	 * All states need lowlevel support and need to be valid to the lowlevel
	 * implementation, no valid callback implies that none are valid.
	 */
	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
}

/**
 * suspend_valid_only_mem - Generic memory-only valid callback.
 *
 * Platform drivers that implement mem suspend only and only need to check for
 * that in their .valid() callback can use this instead of rolling their own
 * .valid() callback.
 */
int suspend_valid_only_mem(suspend_state_t state)
{
	return state == PM_SUSPEND_MEM;
}
EXPORT_SYMBOL_GPL(suspend_valid_only_mem);

static int suspend_test(int level)
{
#ifdef CONFIG_PM_DEBUG
	if (pm_test_level == level) {
		printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
		mdelay(5000);
		return 1;
	}
#endif /* !CONFIG_PM_DEBUG */
	return 0;
}

/**
 * suspend_prepare - Prepare for entering system sleep state.
 *
 * Common code run for every system sleep state that can be entered (except for
 * hibernation).  Run suspend notifiers, allocate the "suspend" console and
 * freeze processes.
 */
static int suspend_prepare(void)
{
	int error;

	if (!suspend_ops || !suspend_ops->enter)
		return -EPERM;

	pm_prepare_console();

	error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
	if (error)
		goto Finish;

	error = usermodehelper_disable();
	if (error)
		goto Finish;

	error = suspend_freeze_processes();
	if (!error)
		return 0;

	suspend_stats.failed_freeze++;
	dpm_save_failed_step(SUSPEND_FREEZE);
	usermodehelper_enable();
 Finish:
	pm_notifier_call_chain(PM_POST_SUSPEND);
	pm_restore_console();
	return error;
}

/* default implementation */
void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
{
	local_irq_disable();
}

/* default implementation */
void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
{
	local_irq_enable();
}

/**
 * suspend_enter - Make the system enter the given sleep state.
 * @state: System sleep state to enter.
 * @wakeup: Returns information that the sleep state should not be re-entered.
 *
 * This function should be called after devices have been suspended.
 */
static int suspend_enter(suspend_state_t state, bool *wakeup)
{
	int error;

	if (suspend_ops->prepare) {
		error = suspend_ops->prepare();
		if (error)
			goto Platform_finish;
	}

	error = dpm_suspend_end(PMSG_SUSPEND);
	if (error) {
		printk(KERN_ERR "PM: Some devices failed to power down\n");
		goto Platform_finish;
	}

	if (suspend_ops->prepare_late) {
		error = suspend_ops->prepare_late();
		if (error)
			goto Platform_wake;
	}

	if (suspend_test(TEST_PLATFORM))
		goto Platform_wake;

	error = disable_nonboot_cpus();
	if (error || suspend_test(TEST_CPUS))
		goto Enable_cpus;

	arch_suspend_disable_irqs();
	BUG_ON(!irqs_disabled());

	error = syscore_suspend();
	if (!error) {
		*wakeup = pm_wakeup_pending();
		if (!(suspend_test(TEST_CORE) || *wakeup)) {
			error = suspend_ops->enter(state);
			events_check_enabled = false;
		}
		syscore_resume();
	}

	arch_suspend_enable_irqs();
	BUG_ON(irqs_disabled());

 Enable_cpus:
	enable_nonboot_cpus();

 Platform_wake:
	if (suspend_ops->wake)
		suspend_ops->wake();

	dpm_resume_start(PMSG_RESUME);

 Platform_finish:
	if (suspend_ops->finish)
		suspend_ops->finish();

	return error;
}

/**
 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
 * @state: System sleep state to enter.
 */
int suspend_devices_and_enter(suspend_state_t state)
{
	int error;
	bool wakeup = false;

	if (!suspend_ops)
		return -ENOSYS;

	trace_machine_suspend(state);
	if (suspend_ops->begin) {
		error = suspend_ops->begin(state);
		if (error)
			goto Close;
	}
	suspend_console();
	suspend_test_start();
	error = dpm_suspend_start(PMSG_SUSPEND);
	if (error) {
		printk(KERN_ERR "PM: Some devices failed to suspend\n");
		goto Recover_platform;
	}
	suspend_test_finish("suspend devices");
	if (suspend_test(TEST_DEVICES))
		goto Recover_platform;

	do {
		error = suspend_enter(state, &wakeup);
	} while (!error && !wakeup
		&& suspend_ops->suspend_again && suspend_ops->suspend_again());

 Resume_devices:
	suspend_test_start();
	dpm_resume_end(PMSG_RESUME);
	suspend_test_finish("resume devices");
	resume_console();
 Close:
	if (suspend_ops->end)
		suspend_ops->end();
	trace_machine_suspend(PWR_EVENT_EXIT);
	return error;

 Recover_platform:
	if (suspend_ops->recover)
		suspend_ops->recover();
	goto Resume_devices;
}

/**
 * suspend_finish - Clean up before finishing the suspend sequence.
 *
 * Call platform code to clean up, restart processes, and free the console that
 * we've allocated. This routine is not called for hibernation.
 */
static void suspend_finish(void)
{
	suspend_thaw_processes();
	usermodehelper_enable();
	pm_notifier_call_chain(PM_POST_SUSPEND);
	pm_restore_console();
}

/**
 * enter_state - Do common work needed to enter system sleep state.
 * @state: System sleep state to enter.
 *
 * Make sure that no one else is trying to put the system into a sleep state.
 * Fail if that's not the case.  Otherwise, prepare for system suspend, make the
 * system enter the given sleep state and clean up after wakeup.
 */
static int enter_state(suspend_state_t state)
{
	int error;

	if (!valid_state(state))
		return -ENODEV;

	if (!mutex_trylock(&pm_mutex))
		return -EBUSY;

	printk(KERN_INFO "PM: Syncing filesystems ... ");
	sys_sync();
	printk("done.\n");

	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
	error = suspend_prepare();
	if (error)
		goto Unlock;

	if (suspend_test(TEST_FREEZER))
		goto Finish;

	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
	pm_restrict_gfp_mask();
	error = suspend_devices_and_enter(state);
	pm_restore_gfp_mask();

 Finish:
	pr_debug("PM: Finishing wakeup.\n");
	suspend_finish();
 Unlock:
	mutex_unlock(&pm_mutex);
	return error;
}

/**
 * pm_suspend - Externally visible function for suspending the system.
 * @state: System sleep state to enter.
 *
 * Check if the value of @state represents one of the supported states,
 * execute enter_state() and update system suspend statistics.
 */
int pm_suspend(suspend_state_t state)
{
	int error;

	if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
		return -EINVAL;

	error = enter_state(state);
	if (error) {
		suspend_stats.fail++;
		dpm_save_failed_errno(error);
	} else {
		suspend_stats.success++;
	}
	return error;
}
EXPORT_SYMBOL(pm_suspend);
Commit	Line	Data
a9d70523 RW	1	/*
	2	* kernel/power/suspend.c - Suspend to RAM and standby functionality.
	3	*
	4	* Copyright (c) 2003 Patrick Mochel
	5	* Copyright (c) 2003 Open Source Development Lab
	6	* Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
	7	*
	8	* This file is released under the GPLv2.
	9	*/
	10
	11	#include <linux/string.h>
	12	#include <linux/delay.h>
	13	#include <linux/errno.h>
	14	#include <linux/init.h>
74da1ff7	15	#include <linux/kmod.h>
a9d70523 RW	16	#include <linux/console.h>
	17	#include <linux/cpu.h>
	18	#include <linux/syscalls.h>
5a0e3ad6	19	#include <linux/gfp.h>
dd4c4f17 MG	20	#include <linux/io.h>
	21	#include <linux/kernel.h>
	22	#include <linux/list.h>
	23	#include <linux/mm.h>
	24	#include <linux/slab.h>
6e5fdeed	25	#include <linux/export.h>
dd4c4f17	26	#include <linux/suspend.h>
40dc166c	27	#include <linux/syscore_ops.h>
938cfed1	28	#include <trace/events/power.h>
a9d70523 RW	29
	30	#include "power.h"
	31
	32	const char *const pm_states[PM_SUSPEND_MAX] = {
	33	[PM_SUSPEND_STANDBY] = "standby",
	34	[PM_SUSPEND_MEM] = "mem",
	35	};
	36
2f55ac07	37	static const struct platform_suspend_ops *suspend_ops;
a9d70523 RW	38
a9d70523 RW	39	/**
55ae4519 RW	40	* suspend_set_ops - Set the global suspend method table.
55ae4519 RW	41	* @ops: Suspend operations to use.
a9d70523	42	*/
2f55ac07	43	void suspend_set_ops(const struct platform_suspend_ops *ops)
a9d70523	44	{
bcda53fa	45	lock_system_sleep();
a9d70523	46	suspend_ops = ops;
bcda53fa	47	unlock_system_sleep();
a9d70523	48	}
a5e4fd87	49	EXPORT_SYMBOL_GPL(suspend_set_ops);
a9d70523 RW	50
	51	bool valid_state(suspend_state_t state)
	52	{
	53	/*
	54	* All states need lowlevel support and need to be valid to the lowlevel
	55	* implementation, no valid callback implies that none are valid.
	56	*/
	57	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
	58	}
	59
	60	/**
55ae4519	61	* suspend_valid_only_mem - Generic memory-only valid callback.
a9d70523	62	*
55ae4519 RW	63	* Platform drivers that implement mem suspend only and only need to check for
	64	* that in their .valid() callback can use this instead of rolling their own
	65	* .valid() callback.
a9d70523 RW	66	*/
	67	int suspend_valid_only_mem(suspend_state_t state)
	68	{
	69	return state == PM_SUSPEND_MEM;
	70	}
a5e4fd87	71	EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
a9d70523 RW	72
	73	static int suspend_test(int level)
	74	{
	75	#ifdef CONFIG_PM_DEBUG
	76	if (pm_test_level == level) {
	77	printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
	78	mdelay(5000);
	79	return 1;
	80	}
	81	#endif /* !CONFIG_PM_DEBUG */
	82	return 0;
	83	}
	84
	85	/**
55ae4519	86	* suspend_prepare - Prepare for entering system sleep state.
a9d70523	87	*
55ae4519 RW	88	* Common code run for every system sleep state that can be entered (except for
	89	* hibernation). Run suspend notifiers, allocate the "suspend" console and
	90	* freeze processes.
a9d70523 RW	91	*/
	92	static int suspend_prepare(void)
	93	{
	94	int error;
	95
	96	if (!suspend_ops \|\| !suspend_ops->enter)
	97	return -EPERM;
	98
	99	pm_prepare_console();
	100
	101	error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
	102	if (error)
	103	goto Finish;
	104
	105	error = usermodehelper_disable();
	106	if (error)
	107	goto Finish;
	108
	109	error = suspend_freeze_processes();
03afed8b	110	if (!error)
a9d70523 RW	111	return 0;
a9d70523 RW	112
03afed8b TH	113	suspend_stats.failed_freeze++;
03afed8b TH	114	dpm_save_failed_step(SUSPEND_FREEZE);
a9d70523 RW	115	usermodehelper_enable();
	116	Finish:
	117	pm_notifier_call_chain(PM_POST_SUSPEND);
	118	pm_restore_console();
	119	return error;
	120	}
	121
	122	/* default implementation */
	123	void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
	124	{
	125	local_irq_disable();
	126	}
	127
	128	/* default implementation */
	129	void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
	130	{
	131	local_irq_enable();
	132	}
	133
	134	/**
55ae4519 RW	135	* suspend_enter - Make the system enter the given sleep state.
	136	* @state: System sleep state to enter.
	137	* @wakeup: Returns information that the sleep state should not be re-entered.
a9d70523	138	*
3b5fe852	139	* This function should be called after devices have been suspended.
a9d70523	140	*/
3b5fe852	141	static int suspend_enter(suspend_state_t state, bool *wakeup)
a9d70523 RW	142	{
	143	int error;
	144
	145	if (suspend_ops->prepare) {
	146	error = suspend_ops->prepare();
	147	if (error)
ce441011	148	goto Platform_finish;
a9d70523 RW	149	}
a9d70523 RW	150
cf579dfb	151	error = dpm_suspend_end(PMSG_SUSPEND);
a9d70523 RW	152	if (error) {
a9d70523 RW	153	printk(KERN_ERR "PM: Some devices failed to power down\n");
ce441011	154	goto Platform_finish;
a9d70523 RW	155	}
	156
	157	if (suspend_ops->prepare_late) {
	158	error = suspend_ops->prepare_late();
	159	if (error)
ce441011	160	goto Platform_wake;
a9d70523 RW	161	}
	162
	163	if (suspend_test(TEST_PLATFORM))
	164	goto Platform_wake;
	165
	166	error = disable_nonboot_cpus();
	167	if (error \|\| suspend_test(TEST_CPUS))
	168	goto Enable_cpus;
	169
	170	arch_suspend_disable_irqs();
	171	BUG_ON(!irqs_disabled());
	172
2e711c04	173	error = syscore_suspend();
a9d70523	174	if (!error) {
3b5fe852 MH	175	*wakeup = pm_wakeup_pending();
3b5fe852 MH	176	if (!(suspend_test(TEST_CORE) \|\| *wakeup)) {
a9d70523	177	error = suspend_ops->enter(state);
c125e96f RW	178	events_check_enabled = false;
c125e96f RW	179	}
40dc166c	180	syscore_resume();
a9d70523 RW	181	}
	182
	183	arch_suspend_enable_irqs();
	184	BUG_ON(irqs_disabled());
	185
	186	Enable_cpus:
	187	enable_nonboot_cpus();
	188
	189	Platform_wake:
	190	if (suspend_ops->wake)
	191	suspend_ops->wake();
	192
cf579dfb	193	dpm_resume_start(PMSG_RESUME);
a9d70523	194
ce441011	195	Platform_finish:
a9d70523 RW	196	if (suspend_ops->finish)
	197	suspend_ops->finish();
	198
	199	return error;
	200	}
	201
	202	/**
55ae4519 RW	203	* suspend_devices_and_enter - Suspend devices and enter system sleep state.
55ae4519 RW	204	* @state: System sleep state to enter.
a9d70523 RW	205	*/
	206	int suspend_devices_and_enter(suspend_state_t state)
	207	{
	208	int error;
3b5fe852	209	bool wakeup = false;
a9d70523 RW	210
	211	if (!suspend_ops)
	212	return -ENOSYS;
	213
938cfed1	214	trace_machine_suspend(state);
a9d70523 RW	215	if (suspend_ops->begin) {
	216	error = suspend_ops->begin(state);
	217	if (error)
	218	goto Close;
	219	}
	220	suspend_console();
	221	suspend_test_start();
	222	error = dpm_suspend_start(PMSG_SUSPEND);
	223	if (error) {
	224	printk(KERN_ERR "PM: Some devices failed to suspend\n");
	225	goto Recover_platform;
	226	}
	227	suspend_test_finish("suspend devices");
	228	if (suspend_test(TEST_DEVICES))
	229	goto Recover_platform;
	230
3b5fe852 MH	231	do {
	232	error = suspend_enter(state, &wakeup);
	233	} while (!error && !wakeup
	234	&& suspend_ops->suspend_again && suspend_ops->suspend_again());
a9d70523 RW	235
	236	Resume_devices:
	237	suspend_test_start();
	238	dpm_resume_end(PMSG_RESUME);
	239	suspend_test_finish("resume devices");
	240	resume_console();
	241	Close:
	242	if (suspend_ops->end)
	243	suspend_ops->end();
938cfed1	244	trace_machine_suspend(PWR_EVENT_EXIT);
a9d70523 RW	245	return error;
	246
	247	Recover_platform:
	248	if (suspend_ops->recover)
	249	suspend_ops->recover();
	250	goto Resume_devices;
	251	}
	252
	253	/**
55ae4519	254	* suspend_finish - Clean up before finishing the suspend sequence.
a9d70523	255	*
55ae4519 RW	256	* Call platform code to clean up, restart processes, and free the console that
55ae4519 RW	257	* we've allocated. This routine is not called for hibernation.
a9d70523 RW	258	*/
	259	static void suspend_finish(void)
	260	{
	261	suspend_thaw_processes();
	262	usermodehelper_enable();
	263	pm_notifier_call_chain(PM_POST_SUSPEND);
	264	pm_restore_console();
	265	}
	266
	267	/**
55ae4519 RW	268	* enter_state - Do common work needed to enter system sleep state.
55ae4519 RW	269	* @state: System sleep state to enter.
a9d70523	270	*
55ae4519 RW	271	* Make sure that no one else is trying to put the system into a sleep state.
	272	* Fail if that's not the case. Otherwise, prepare for system suspend, make the
	273	* system enter the given sleep state and clean up after wakeup.
a9d70523	274	*/
93e1ee43	275	static int enter_state(suspend_state_t state)
a9d70523 RW	276	{
	277	int error;
	278
	279	if (!valid_state(state))
	280	return -ENODEV;
	281
	282	if (!mutex_trylock(&pm_mutex))
	283	return -EBUSY;
	284
	285	printk(KERN_INFO "PM: Syncing filesystems ... ");
	286	sys_sync();
	287	printk("done.\n");
	288
	289	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
	290	error = suspend_prepare();
	291	if (error)
	292	goto Unlock;
	293
	294	if (suspend_test(TEST_FREEZER))
	295	goto Finish;
	296
	297	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
87186475	298	pm_restrict_gfp_mask();
a9d70523	299	error = suspend_devices_and_enter(state);
87186475	300	pm_restore_gfp_mask();
a9d70523 RW	301
	302	Finish:
	303	pr_debug("PM: Finishing wakeup.\n");
	304	suspend_finish();
	305	Unlock:
	306	mutex_unlock(&pm_mutex);
	307	return error;
	308	}
	309
	310	/**
55ae4519 RW	311	* pm_suspend - Externally visible function for suspending the system.
55ae4519 RW	312	* @state: System sleep state to enter.
a9d70523	313	*
55ae4519 RW	314	* Check if the value of @state represents one of the supported states,
55ae4519 RW	315	* execute enter_state() and update system suspend statistics.
a9d70523 RW	316	*/
	317	int pm_suspend(suspend_state_t state)
	318	{
bc25cf50 RW	319	int error;
	320
	321	if (state <= PM_SUSPEND_ON \|\| state >= PM_SUSPEND_MAX)
	322	return -EINVAL;
	323
	324	error = enter_state(state);
	325	if (error) {
	326	suspend_stats.fail++;
	327	dpm_save_failed_errno(error);
	328	} else {
	329	suspend_stats.success++;
2a77c46d	330	}
bc25cf50	331	return error;
a9d70523 RW	332	}
a9d70523 RW	333	EXPORT_SYMBOL(pm_suspend);