[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/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:	Pointer to ops structure.
 */
void suspend_set_ops(const struct platform_suspend_ops *ops)
{
	mutex_lock(&pm_mutex);
	suspend_ops = ops;
	mutex_unlock(&pm_mutex);
}
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 - Do prep work before entering low-power state.
 *
 *	This is common code that is called for each state that we're entering.
 *	Run suspend notifiers, allocate a console and stop all 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) {
		suspend_stats.failed_freeze++;
		dpm_save_failed_step(SUSPEND_FREEZE);
	} else
		return 0;

	suspend_thaw_processes();
	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 - enter the desired system sleep state.
 * @state: State to enter
 * @wakeup: Returns information that suspend should not be entered again.
 *
 * 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_noirq(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_noirq(PMSG_RESUME);

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

	return error;
}

/**
 *	suspend_devices_and_enter - suspend devices and enter the desired system
 *				    sleep state.
 *	@state:		  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 - Do final work before exiting suspend sequence.
 *
 *	Call platform code to clean up, restart processes, and free the
 *	console that we've allocated. This is not called for suspend-to-disk.
 */
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 of entering low-power state.
 *	@state:		pm_state structure for state we're entering.
 *
 *	Make sure we're the only ones trying to enter a sleep state. Fail
 *	if someone has beat us to it, since we don't want anything weird to
 *	happen when we wake up.
 *	Then, do the setup for suspend, enter the state, and cleaup (after
 *	we've woken up).
 */
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 system.
 *	@state:		Enumerated value of state to enter.
 *
 *	Determine whether or not value is within range, get state
 *	structure, and enter (above).
 */
int pm_suspend(suspend_state_t state)
{
	int ret;
	if (state > PM_SUSPEND_ON && state < PM_SUSPEND_MAX) {
		ret = enter_state(state);
		if (ret) {
			suspend_stats.fail++;
			dpm_save_failed_errno(ret);
		} else
			suspend_stats.success++;
		return ret;
	}
	return -EINVAL;
}
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>
	25	#include <linux/suspend.h>
40dc166c	26	#include <linux/syscore_ops.h>
938cfed1	27	#include <trace/events/power.h>
a9d70523 RW	28
	29	#include "power.h"
	30
	31	const char *const pm_states[PM_SUSPEND_MAX] = {
	32	[PM_SUSPEND_STANDBY] = "standby",
	33	[PM_SUSPEND_MEM] = "mem",
	34	};
	35
2f55ac07	36	static const struct platform_suspend_ops *suspend_ops;
a9d70523 RW	37
	38	/**
	39	* suspend_set_ops - Set the global suspend method table.
	40	* @ops: Pointer to ops structure.
	41	*/
2f55ac07	42	void suspend_set_ops(const struct platform_suspend_ops *ops)
a9d70523 RW	43	{
	44	mutex_lock(&pm_mutex);
	45	suspend_ops = ops;
	46	mutex_unlock(&pm_mutex);
	47	}
a5e4fd87	48	EXPORT_SYMBOL_GPL(suspend_set_ops);
a9d70523 RW	49
	50	bool valid_state(suspend_state_t state)
	51	{
	52	/*
	53	* All states need lowlevel support and need to be valid to the lowlevel
	54	* implementation, no valid callback implies that none are valid.
	55	*/
	56	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
	57	}
	58
	59	/**
	60	* suspend_valid_only_mem - generic memory-only valid callback
	61	*
	62	* Platform drivers that implement mem suspend only and only need
	63	* to check for that in their .valid callback can use this instead
	64	* of rolling their own .valid callback.
	65	*/
	66	int suspend_valid_only_mem(suspend_state_t state)
	67	{
	68	return state == PM_SUSPEND_MEM;
	69	}
a5e4fd87	70	EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
a9d70523 RW	71
	72	static int suspend_test(int level)
	73	{
	74	#ifdef CONFIG_PM_DEBUG
	75	if (pm_test_level == level) {
	76	printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
	77	mdelay(5000);
	78	return 1;
	79	}
	80	#endif /* !CONFIG_PM_DEBUG */
	81	return 0;
	82	}
	83
	84	/**
	85	* suspend_prepare - Do prep work before entering low-power state.
	86	*
	87	* This is common code that is called for each state that we're entering.
	88	* Run suspend notifiers, allocate a console and stop all processes.
	89	*/
	90	static int suspend_prepare(void)
	91	{
	92	int error;
	93
	94	if (!suspend_ops \|\| !suspend_ops->enter)
	95	return -EPERM;
	96
	97	pm_prepare_console();
	98
	99	error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
	100	if (error)
	101	goto Finish;
	102
	103	error = usermodehelper_disable();
	104	if (error)
	105	goto Finish;
	106
	107	error = suspend_freeze_processes();
2a77c46d SL	108	if (error) {
	109	suspend_stats.failed_freeze++;
	110	dpm_save_failed_step(SUSPEND_FREEZE);
	111	} else
a9d70523 RW	112	return 0;
	113
	114	suspend_thaw_processes();
	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	/**
3b5fe852 MH	135	* suspend_enter - enter the desired system sleep state.
	136	* @state: State to enter
	137	* @wakeup: Returns information that suspend should not be entered again.
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	}
	150
	151	error = dpm_suspend_noirq(PMSG_SUSPEND);
	152	if (error) {
	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
a9d70523 RW	193	dpm_resume_noirq(PMSG_RESUME);
a9d70523 RW	194
ce441011	195	Platform_finish:
a9d70523 RW	196	if (suspend_ops->finish)
	197	suspend_ops->finish();
	198
	199	return error;
	200	}
	201
	202	/**
	203	* suspend_devices_and_enter - suspend devices and enter the desired system
	204	* sleep state.
	205	* @state: state to enter
	206	*/
	207	int suspend_devices_and_enter(suspend_state_t state)
	208	{
	209	int error;
3b5fe852	210	bool wakeup = false;
a9d70523 RW	211
	212	if (!suspend_ops)
	213	return -ENOSYS;
	214
938cfed1	215	trace_machine_suspend(state);
a9d70523 RW	216	if (suspend_ops->begin) {
	217	error = suspend_ops->begin(state);
	218	if (error)
	219	goto Close;
	220	}
	221	suspend_console();
	222	suspend_test_start();
	223	error = dpm_suspend_start(PMSG_SUSPEND);
	224	if (error) {
	225	printk(KERN_ERR "PM: Some devices failed to suspend\n");
	226	goto Recover_platform;
	227	}
	228	suspend_test_finish("suspend devices");
	229	if (suspend_test(TEST_DEVICES))
	230	goto Recover_platform;
	231
3b5fe852 MH	232	do {
	233	error = suspend_enter(state, &wakeup);
	234	} while (!error && !wakeup
	235	&& suspend_ops->suspend_again && suspend_ops->suspend_again());
a9d70523 RW	236
	237	Resume_devices:
	238	suspend_test_start();
	239	dpm_resume_end(PMSG_RESUME);
	240	suspend_test_finish("resume devices");
	241	resume_console();
	242	Close:
	243	if (suspend_ops->end)
	244	suspend_ops->end();
938cfed1	245	trace_machine_suspend(PWR_EVENT_EXIT);
a9d70523 RW	246	return error;
	247
	248	Recover_platform:
	249	if (suspend_ops->recover)
	250	suspend_ops->recover();
	251	goto Resume_devices;
	252	}
	253
	254	/**
	255	* suspend_finish - Do final work before exiting suspend sequence.
	256	*
	257	* Call platform code to clean up, restart processes, and free the
	258	* console that we've allocated. This is not called for suspend-to-disk.
	259	*/
	260	static void suspend_finish(void)
	261	{
	262	suspend_thaw_processes();
	263	usermodehelper_enable();
	264	pm_notifier_call_chain(PM_POST_SUSPEND);
	265	pm_restore_console();
	266	}
	267
	268	/**
	269	* enter_state - Do common work of entering low-power state.
	270	* @state: pm_state structure for state we're entering.
	271	*
	272	* Make sure we're the only ones trying to enter a sleep state. Fail
	273	* if someone has beat us to it, since we don't want anything weird to
	274	* happen when we wake up.
	275	* Then, do the setup for suspend, enter the state, and cleaup (after
	276	* we've woken up).
	277	*/
	278	int enter_state(suspend_state_t state)
	279	{
	280	int error;
	281
	282	if (!valid_state(state))
	283	return -ENODEV;
	284
	285	if (!mutex_trylock(&pm_mutex))
	286	return -EBUSY;
	287
	288	printk(KERN_INFO "PM: Syncing filesystems ... ");
	289	sys_sync();
	290	printk("done.\n");
	291
	292	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
	293	error = suspend_prepare();
	294	if (error)
	295	goto Unlock;
	296
	297	if (suspend_test(TEST_FREEZER))
	298	goto Finish;
	299
	300	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
87186475	301	pm_restrict_gfp_mask();
a9d70523	302	error = suspend_devices_and_enter(state);
87186475	303	pm_restore_gfp_mask();
a9d70523 RW	304
	305	Finish:
	306	pr_debug("PM: Finishing wakeup.\n");
	307	suspend_finish();
	308	Unlock:
	309	mutex_unlock(&pm_mutex);
	310	return error;
	311	}
	312
	313	/**
	314	* pm_suspend - Externally visible function for suspending system.
	315	* @state: Enumerated value of state to enter.
	316	*
	317	* Determine whether or not value is within range, get state
	318	* structure, and enter (above).
	319	*/
	320	int pm_suspend(suspend_state_t state)
	321	{
2a77c46d	322	int ret;
528f7ce6	323	if (state > PM_SUSPEND_ON && state < PM_SUSPEND_MAX) {
2a77c46d SL	324	ret = enter_state(state);
	325	if (ret) {
	326	suspend_stats.fail++;
	327	dpm_save_failed_errno(ret);
	328	} else
	329	suspend_stats.success++;
	330	return ret;
	331	}
a9d70523 RW	332	return -EINVAL;
	333	}
	334	EXPORT_SYMBOL(pm_suspend);