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

/* kernel/power/fbearlysuspend.c
 *
 * Copyright (C) 2005-2008 Google, Inc.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include <linux/earlysuspend.h>
#include <linux/module.h>
#include <linux/wait.h>

#include "power.h"

static wait_queue_head_t fb_state_wq;
static DEFINE_SPINLOCK(fb_state_lock);
static enum {
	FB_STATE_STOPPED_DRAWING,
	FB_STATE_REQUEST_STOP_DRAWING,
	FB_STATE_DRAWING_OK,
} fb_state;

/* tell userspace to stop drawing, wait for it to stop */
static void stop_drawing_early_suspend(struct early_suspend *h)
{
	int ret;
	unsigned long irq_flags;

	spin_lock_irqsave(&fb_state_lock, irq_flags);
	fb_state = FB_STATE_REQUEST_STOP_DRAWING;
	spin_unlock_irqrestore(&fb_state_lock, irq_flags);

	wake_up_all(&fb_state_wq);
	ret = wait_event_timeout(fb_state_wq, fb_state == FB_STATE_STOPPED_DRAWING, HZ);
	if (unlikely(fb_state != FB_STATE_STOPPED_DRAWING))
		pr_warn("stop_drawing_early_suspend: timeout waiting for "
			   "userspace to stop drawing\n");
}

/* tell userspace to start drawing */
static void start_drawing_late_resume(struct early_suspend *h)
{
	unsigned long irq_flags;

	spin_lock_irqsave(&fb_state_lock, irq_flags);
	fb_state = FB_STATE_DRAWING_OK;
	spin_unlock_irqrestore(&fb_state_lock, irq_flags);
	wake_up(&fb_state_wq);
}

static struct early_suspend stop_drawing_early_suspend_desc = {
	.level = EARLY_SUSPEND_LEVEL_STOP_DRAWING,
	.suspend = stop_drawing_early_suspend,
	.resume = start_drawing_late_resume,
};

static ssize_t wait_for_fb_sleep_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
{
	char *s = buf;
	int ret;

	ret = wait_event_interruptible(fb_state_wq, fb_state != FB_STATE_DRAWING_OK);
	if (ret && fb_state == FB_STATE_DRAWING_OK)
		return ret;
	else
		s += sprintf(buf, "sleeping");
	return s - buf;
}

static ssize_t wait_for_fb_wake_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
{
	char *s = buf;
	int ret;
	unsigned long irq_flags;

	spin_lock_irqsave(&fb_state_lock, irq_flags);
	if (fb_state == FB_STATE_REQUEST_STOP_DRAWING) {
		fb_state = FB_STATE_STOPPED_DRAWING;
		wake_up(&fb_state_wq);
	}
	spin_unlock_irqrestore(&fb_state_lock, irq_flags);

	ret = wait_event_interruptible(fb_state_wq, fb_state == FB_STATE_DRAWING_OK);
	if (ret && fb_state != FB_STATE_DRAWING_OK)
		return ret;
	else
		s += sprintf(buf, "awake");

	return s - buf;
}

#define power_ro_attr(_name) \
static struct kobj_attribute _name##_attr = {	\
	.attr	= {				\
		.name = __stringify(_name),	\
		.mode = 0444,			\
	},					\
	.show	= _name##_show,			\
	.store	= NULL,		\
}

power_ro_attr(wait_for_fb_sleep);
power_ro_attr(wait_for_fb_wake);

static struct attribute *g[] = {
	&wait_for_fb_sleep_attr.attr,
	&wait_for_fb_wake_attr.attr,
	NULL,
};

static struct attribute_group attr_group = {
	.attrs = g,
};

static int __init android_power_init(void)
{
	int ret;

	init_waitqueue_head(&fb_state_wq);
	fb_state = FB_STATE_DRAWING_OK;

	ret = sysfs_create_group(power_kobj, &attr_group);
	if (ret) {
		pr_err("android_power_init: sysfs_create_group failed\n");
		return ret;
	}

	register_early_suspend(&stop_drawing_early_suspend_desc);
	return 0;
}

static void __exit android_power_exit(void)
{
	unregister_early_suspend(&stop_drawing_early_suspend_desc);
	sysfs_remove_group(power_kobj, &attr_group);
}
module_init(android_power_init);
module_exit(android_power_exit);
Commit	Line	Data
6fa3eb70 S	1	/* kernel/power/fbearlysuspend.c
	2	*
	3	* Copyright (C) 2005-2008 Google, Inc.
	4	*
	5	* This software is licensed under the terms of the GNU General Public
	6	* License version 2, as published by the Free Software Foundation, and
	7	* may be copied, distributed, and modified under those terms.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	*/
	15
	16	#include <linux/earlysuspend.h>
	17	#include <linux/module.h>
	18	#include <linux/wait.h>
	19
	20	#include "power.h"
	21
	22	static wait_queue_head_t fb_state_wq;
	23	static DEFINE_SPINLOCK(fb_state_lock);
	24	static enum {
	25	FB_STATE_STOPPED_DRAWING,
	26	FB_STATE_REQUEST_STOP_DRAWING,
	27	FB_STATE_DRAWING_OK,
	28	} fb_state;
	29
	30	/* tell userspace to stop drawing, wait for it to stop */
	31	static void stop_drawing_early_suspend(struct early_suspend *h)
	32	{
	33	int ret;
	34	unsigned long irq_flags;
	35
	36	spin_lock_irqsave(&fb_state_lock, irq_flags);
	37	fb_state = FB_STATE_REQUEST_STOP_DRAWING;
	38	spin_unlock_irqrestore(&fb_state_lock, irq_flags);
	39
	40	wake_up_all(&fb_state_wq);
	41	ret = wait_event_timeout(fb_state_wq, fb_state == FB_STATE_STOPPED_DRAWING, HZ);
	42	if (unlikely(fb_state != FB_STATE_STOPPED_DRAWING))
	43	pr_warn("stop_drawing_early_suspend: timeout waiting for "
	44	"userspace to stop drawing\n");
	45	}
	46
	47	/* tell userspace to start drawing */
	48	static void start_drawing_late_resume(struct early_suspend *h)
	49	{
	50	unsigned long irq_flags;
	51
	52	spin_lock_irqsave(&fb_state_lock, irq_flags);
	53	fb_state = FB_STATE_DRAWING_OK;
	54	spin_unlock_irqrestore(&fb_state_lock, irq_flags);
	55	wake_up(&fb_state_wq);
	56	}
	57
	58	static struct early_suspend stop_drawing_early_suspend_desc = {
	59	.level = EARLY_SUSPEND_LEVEL_STOP_DRAWING,
	60	.suspend = stop_drawing_early_suspend,
	61	.resume = start_drawing_late_resume,
	62	};
	63
	64	static ssize_t wait_for_fb_sleep_show(struct kobject kobj, struct kobj_attribute attr, char *buf)
65	{
66	char *s = buf;
67	int ret;
68
69	ret = wait_event_interruptible(fb_state_wq, fb_state != FB_STATE_DRAWING_OK);
70	if (ret && fb_state == FB_STATE_DRAWING_OK)
71	return ret;
72	else
73	s += sprintf(buf, "sleeping");
74	return s - buf;
75	}
76
77	static ssize_t wait_for_fb_wake_show(struct kobject kobj, struct kobj_attribute attr, char *buf)
78	{
79	char *s = buf;
80	int ret;
81	unsigned long irq_flags;
82
83	spin_lock_irqsave(&fb_state_lock, irq_flags);
84	if (fb_state == FB_STATE_REQUEST_STOP_DRAWING) {
85	fb_state = FB_STATE_STOPPED_DRAWING;
86	wake_up(&fb_state_wq);
87	}
88	spin_unlock_irqrestore(&fb_state_lock, irq_flags);
89
90	ret = wait_event_interruptible(fb_state_wq, fb_state == FB_STATE_DRAWING_OK);
91	if (ret && fb_state != FB_STATE_DRAWING_OK)
92	return ret;
93	else
94	s += sprintf(buf, "awake");
95
96	return s - buf;
97	}
98
99	#define power_ro_attr(_name) \
100	static struct kobj_attribute _name##_attr = { \
101	.attr = { \
102	.name = __stringify(_name), \
103	.mode = 0444, \
104	}, \
105	.show = _name##_show, \
106	.store = NULL, \
107	}
108
109	power_ro_attr(wait_for_fb_sleep);
110	power_ro_attr(wait_for_fb_wake);
111
112	static struct attribute *g[] = {
113	&wait_for_fb_sleep_attr.attr,
114	&wait_for_fb_wake_attr.attr,
115	NULL,
116	};
117
118	static struct attribute_group attr_group = {
119	.attrs = g,
120	};
121
122	static int __init android_power_init(void)
123	{
124	int ret;
125
126	init_waitqueue_head(&fb_state_wq);
127	fb_state = FB_STATE_DRAWING_OK;
128
129	ret = sysfs_create_group(power_kobj, &attr_group);
130	if (ret) {
131	pr_err("android_power_init: sysfs_create_group failed\n");
132	return ret;
133	}
134
135	register_early_suspend(&stop_drawing_early_suspend_desc);
136	return 0;
137	}
138
139	static void __exit android_power_exit(void)
140	{
141	unregister_early_suspend(&stop_drawing_early_suspend_desc);
142	sysfs_remove_group(power_kobj, &attr_group);
143	}
144	module_init(android_power_init);
145	module_exit(android_power_exit);