From: Ruchi Kandoi Date: Wed, 19 Feb 2014 23:30:47 +0000 (-0800) Subject: Power: add an API to log wakeup reasons X-Git-Tag: firefly_0821_release~4090^2~373 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=520bc0723d8046c97b43c41080a425f007e89b31;p=firefly-linux-kernel-4.4.55.git Power: add an API to log wakeup reasons Add API log_wakeup_reason() and expose it to userspace via sysfs path /sys/kernel/wakeup_reasons/last_resume_reason Change-Id: I81addaf420f1338255c5d0638b0d244a99d777d1 Signed-off-by: Ruchi Kandoi --- diff --git a/include/linux/wakeup_reason.h b/include/linux/wakeup_reason.h new file mode 100644 index 000000000000..7ce50f0debc4 --- /dev/null +++ b/include/linux/wakeup_reason.h @@ -0,0 +1,23 @@ +/* + * include/linux/wakeup_reason.h + * + * Logs the reason which caused the kernel to resume + * from the suspend mode. + * + * Copyright (C) 2014 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. + */ + +#ifndef _LINUX_WAKEUP_REASON_H +#define _LINUX_WAKEUP_REASON_H + +void log_wakeup_reason(int irq); + +#endif /* _LINUX_WAKEUP_REASON_H */ diff --git a/kernel/power/Makefile b/kernel/power/Makefile index 8450b85d33c0..74c713ba61b0 100644 --- a/kernel/power/Makefile +++ b/kernel/power/Makefile @@ -14,3 +14,5 @@ obj-$(CONFIG_PM_WAKELOCKS) += wakelock.o obj-$(CONFIG_SUSPEND_TIME) += suspend_time.o obj-$(CONFIG_MAGIC_SYSRQ) += poweroff.o + +obj-$(CONFIG_SUSPEND) += wakeup_reason.o diff --git a/kernel/power/wakeup_reason.c b/kernel/power/wakeup_reason.c new file mode 100644 index 000000000000..ae9bfece9d9a --- /dev/null +++ b/kernel/power/wakeup_reason.c @@ -0,0 +1,132 @@ +/* + * kernel/power/wakeup_reason.c + * + * Logs the reasons which caused the kernel to resume from + * the suspend mode. + * + * Copyright (C) 2014 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + + +#define MAX_WAKEUP_REASON_IRQS 32 +static int irq_list[MAX_WAKEUP_REASON_IRQS]; +static int irq_count; +static struct kobject *wakeup_reason; +static spinlock_t resume_reason_lock; + +static ssize_t reason_show(struct kobject *kobj, struct kobj_attribute *attr, + const char *buf, size_t count) +{ + int irq_no, buf_offset = 0; + struct irq_desc *desc; + spin_lock(&resume_reason_lock); + for (irq_no = 0; irq_no < irq_count; irq_no++) { + desc = irq_to_desc(irq_list[irq_no]); + if (desc && desc->action && desc->action->name) + buf_offset += sprintf(buf + buf_offset, "%d %s\n", + irq_list[irq_no], desc->action->name); + else + buf_offset += sprintf(buf + buf_offset, "%d\n", + irq_list[irq_no]); + } + spin_unlock(&resume_reason_lock); + return buf_offset; +} + +static struct kobj_attribute resume_reason = __ATTR(last_resume_reason, 0666, + reason_show, NULL); + +static struct attribute *attrs[] = { + &resume_reason.attr, + NULL, +}; +static struct attribute_group attr_group = { + .attrs = attrs, +}; + +/* + * logs all the wake up reasons to the kernel + * stores the irqs to expose them to the userspace via sysfs + */ +void log_wakeup_reason(int irq) +{ + struct irq_desc *desc; + desc = irq_to_desc(irq); + if (desc && desc->action && desc->action->name) + printk(KERN_INFO "Resume caused by IRQ %d, %s\n", irq, + desc->action->name); + else + printk(KERN_INFO "Resume caused by IRQ %d\n", irq); + + spin_lock(&resume_reason_lock); + irq_list[irq_count++] = irq; + spin_unlock(&resume_reason_lock); +} + +/* Detects a suspend and clears all the previous wake up reasons*/ +static int wakeup_reason_pm_event(struct notifier_block *notifier, + unsigned long pm_event, void *unused) +{ + switch (pm_event) { + case PM_SUSPEND_PREPARE: + spin_lock(&resume_reason_lock); + irq_count = 0; + spin_unlock(&resume_reason_lock); + break; + default: + break; + } + return NOTIFY_DONE; +} + +static struct notifier_block wakeup_reason_pm_notifier_block = { + .notifier_call = wakeup_reason_pm_event, +}; + +/* Initializes the sysfs parameter + * registers the pm_event notifier + */ +void __init wakeup_reason_init(void) +{ + int retval; + spin_lock_init(&resume_reason_lock); + retval = register_pm_notifier(&wakeup_reason_pm_notifier_block); + if (retval) + printk(KERN_WARNING "[%s] failed to register PM notifier %d\n", + __func__, retval); + + wakeup_reason = kobject_create_and_add("wakeup_reasons", kernel_kobj); + if (!wakeup_reason) { + printk(KERN_WARNING "[%s] failed to create a sysfs kobject\n", + __func__); + return; + } + retval = sysfs_create_group(wakeup_reason, &attr_group); + if (retval) { + kobject_put(wakeup_reason); + printk(KERN_WARNING "[%s] failed to create a sysfs group %d\n", + __func__, retval); + } +} + +late_initcall(wakeup_reason_init);