initial_commit

1 files changed, 153 insertions, 0 deletions

diff --git a/kernel/power/fbearlysuspend.c b/kernel/power/fbearlysuspend.c
new file mode 100644
index 00000000..15137650
--- /dev/null
+++ b/kernel/power/fbearlysuspend.c
@@ -0,0 +1,153 @@
+/* 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_warning("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);
+