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/*
* Author: Paul Reioux aka Faux123 <reioux@gmail.com>
*
* Copyright 2013 Paul Reioux
* Copyright 2012 Paul Reioux
*
* 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/module.h>
#include <linux/kobject.h>
#include <linux/sysfs.h>
#include <linux/mutex.h>
#include <linux/writeback.h>
#include <linux/fb.h>
#define DYN_FSYNC_VERSION_MAJOR 1
#define DYN_FSYNC_VERSION_MINOR 1
struct notifier_block dyn_fsync_fb_notif;
/*
* fsync_mutex protects dyn_fsync_active during fb suspend / resume
* transitions
*/
static DEFINE_MUTEX(fsync_mutex);
bool dyn_sync_scr_suspended;
bool dyn_fsync_active __read_mostly = true;
extern void dyn_fsync_suspend_actions(void);
static ssize_t dyn_fsync_active_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return sprintf(buf, "%u\n", (dyn_fsync_active ? 1 : 0));
}
static ssize_t dyn_fsync_active_store(struct kobject *kobj,
struct kobj_attribute *attr, const char *buf, size_t count)
{
unsigned int data;
if (sscanf(buf, "%u\n", &data) == 1) {
if (data == 1) {
pr_info("%s: dynamic fsync enabled\n", __func__);
dyn_fsync_active = true;
} else if (data == 0) {
pr_info("%s: dyanamic fsync disabled\n", __func__);
dyn_fsync_active = false;
} else
pr_info("%s: bad value: %u\n", __func__, data);
} else
pr_info("%s: unknown input!\n", __func__);
return count;
}
static ssize_t dyn_fsync_version_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return sprintf(buf, "version: %u.%u by faux123\n",
DYN_FSYNC_VERSION_MAJOR,
DYN_FSYNC_VERSION_MINOR);
}
static struct kobj_attribute dyn_fsync_active_attribute =
__ATTR(Dyn_fsync_active, 0660,
dyn_fsync_active_show,
dyn_fsync_active_store);
static struct kobj_attribute dyn_fsync_version_attribute =
__ATTR(Dyn_fsync_version, 0444, dyn_fsync_version_show, NULL);
static struct attribute *dyn_fsync_active_attrs[] = {
&dyn_fsync_active_attribute.attr,
&dyn_fsync_version_attribute.attr,
NULL,
};
static struct attribute_group dyn_fsync_active_attr_group = {
.attrs = dyn_fsync_active_attrs,
};
static struct kobject *dyn_fsync_kobj;
static void dyn_fsync_suspend(void)
{
mutex_lock(&fsync_mutex);
/* flush all outstanding buffers */
if (dyn_fsync_active)
dyn_fsync_suspend_actions();
mutex_unlock(&fsync_mutex);
pr_info("%s: flushing work finished.\n", __func__);
}
static int dyn_fsync_fb_notifier_callback(struct notifier_block *self,
unsigned long event, void *data)
{
struct fb_event *evdata = data;
int *blank;
if (event == FB_EVENT_BLANK) {
blank = evdata->data;
switch (*blank) {
case FB_BLANK_UNBLANK:
dyn_sync_scr_suspended = false;
break;
case FB_BLANK_POWERDOWN:
dyn_sync_scr_suspended = true;
if (dyn_fsync_active)
dyn_fsync_suspend();
break;
}
}
return 0;
}
struct notifier_block dyn_fsync_fb_notif = {
.notifier_call = dyn_fsync_fb_notifier_callback,
};
static int __init dyn_fsync_init(void)
{
int ret;
ret = fb_register_client(&dyn_fsync_fb_notif);
if (ret) {
pr_info("%s fb register failed!\n", __func__);
return ret;
}
dyn_fsync_kobj = kobject_create_and_add("dyn_fsync", kernel_kobj);
if (!dyn_fsync_kobj) {
pr_err("%s dyn_fsync kobject create failed!\n", __func__);
return -ENOMEM;
}
ret = sysfs_create_group(dyn_fsync_kobj,
&dyn_fsync_active_attr_group);
if (ret) {
pr_info("%s dyn_fsync sysfs create failed!\n", __func__);
kobject_put(dyn_fsync_kobj);
}
return ret;
}
static void __exit dyn_fsync_exit(void)
{
if (dyn_fsync_kobj != NULL)
kobject_put(dyn_fsync_kobj);
fb_unregister_client(&dyn_fsync_fb_notif);
}
module_init(dyn_fsync_init);
module_exit(dyn_fsync_exit);
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