*
* Logs the reasons which caused the kernel to resume from
* the suspend mode.
+ * Sends uevent to user space when enter or out of suspend,
+ * the modules of user space can use it to do some necessary
+ * operation. for example, sending a special signal to modem
+ * or controling the brightness of a lamp before or after suspend.
*
* Copyright (C) 2014 Google, Inc.
+ * Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ *
* 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.
#include <linux/spinlock.h>
#include <linux/notifier.h>
#include <linux/suspend.h>
-
+#include <linux/kobject.h>
+#include <linux/suspend.h>
#define MAX_WAKEUP_REASON_IRQS 32
static int irq_list[MAX_WAKEUP_REASON_IRQS];
static ktime_t last_stime; /* monotonic boottime offset before last suspend */
static ktime_t curr_stime; /* monotonic boottime offset after last suspend */
+static struct class *wake_uevent_class;
+static struct device *wake_uevent_device;
+
static ssize_t last_resume_reason_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
static int wakeup_reason_pm_event(struct notifier_block *notifier,
unsigned long pm_event, void *unused)
{
+ int ret = 0;
+ static char envp[32] = {0};
+ static const char * const evp[] = {envp, NULL};
+
switch (pm_event) {
case PM_SUSPEND_PREPARE:
spin_lock(&resume_reason_lock);
irqcount = 0;
suspend_abort = false;
spin_unlock(&resume_reason_lock);
+ /* send the uevent to userspace */
+ snprintf(envp, 32, "STATE=%s", "suspend start");
+ ret = kobject_uevent_env(&wake_uevent_device->kobj,
+ KOBJ_CHANGE, (char **)evp);
+ if (ret)
+ pr_warn("Send uevent failed");
/* monotonic time since boot */
last_monotime = ktime_get();
/* monotonic time since boot including the time spent in suspend */
curr_monotime = ktime_get();
/* monotonic time since boot including the time spent in suspend */
curr_stime = ktime_get_boottime();
+ /* send the uevent to userspace */
+ snprintf(envp, 32, "STATE=%s", "resume complete");
+ ret = kobject_uevent_env(&wake_uevent_device->kobj,
+ KOBJ_CHANGE, (char **)evp);
+ if (ret)
+ pr_warn("Send uevent failed");
break;
default:
break;
.notifier_call = wakeup_reason_pm_event,
};
+static const struct file_operations wakeup_uevent = {
+ .owner = THIS_MODULE,
+};
+
/* Initializes the sysfs parameter
* registers the pm_event notifier
+ * register the wake_uevent device
*/
int __init wakeup_reason_init(void)
{
int retval;
+ int major;
retval = register_pm_notifier(&wakeup_reason_pm_notifier_block);
if (retval)
kobject_put(wakeup_reason);
printk(KERN_WARNING "[%s] failed to create a sysfs group %d\n",
__func__, retval);
+ return retval;
+ }
+ major = register_chrdev(0, "wake_uevent", &wakeup_uevent);
+ if (major < 0) {
+ sysfs_remove_group(wakeup_reason, &attr_group);
+ kobject_put(wakeup_reason);
+ return major;
+ }
+ wake_uevent_class = class_create(THIS_MODULE, "wake_uevent");
+ if (IS_ERR(wake_uevent_class)) {
+ retval = PTR_ERR(wake_uevent_class);
+ goto fail_class;
}
+ wake_uevent_device = device_create(wake_uevent_class, NULL,
+ MKDEV(major, 0),
+ NULL, "wake_uevent");
+ if (IS_ERR(wake_uevent_device)) {
+ retval = PTR_ERR(wake_uevent_device);
+ goto fail_device;
+ }
+
return 0;
+
+fail_device:
+ class_destroy(wake_uevent_class);
+fail_class:
+ unregister_chrdev(major, "wake_uevent");
+ sysfs_remove_group(wakeup_reason, &attr_group);
+ kobject_put(wakeup_reason);
+ return retval;
}
late_initcall(wakeup_reason_init);