diff options
Diffstat (limited to 'kernel/power/wakeup_reason.c')
| -rw-r--r-- | kernel/power/wakeup_reason.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/kernel/power/wakeup_reason.c b/kernel/power/wakeup_reason.c new file mode 100644 index 000000000000..085c99edca06 --- /dev/null +++ b/kernel/power/wakeup_reason.c @@ -0,0 +1,180 @@ +/* + * 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 <linux/wakeup_reason.h> +#include <linux/kernel.h> +#include <linux/irq.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kobject.h> +#include <linux/sysfs.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/notifier.h> +#include <linux/suspend.h> + + +#define MAX_WAKEUP_REASON_IRQS 32 +static int irq_list[MAX_WAKEUP_REASON_IRQS]; +static int irqcount; +static bool suspend_abort; +static char abort_reason[MAX_SUSPEND_ABORT_LEN]; +static struct kobject *wakeup_reason; +static DEFINE_SPINLOCK(resume_reason_lock); + +static ssize_t last_resume_reason_show(struct kobject *kobj, struct kobj_attribute *attr, + char *buf) +{ + int irq_no, buf_offset = 0; + struct irq_desc *desc; + spin_lock(&resume_reason_lock); + if (suspend_abort) { + buf_offset = sprintf(buf, "Abort: %s", abort_reason); + } else { + for (irq_no = 0; irq_no < irqcount; 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_RO(last_resume_reason); + +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); + if (irqcount == MAX_WAKEUP_REASON_IRQS) { + spin_unlock(&resume_reason_lock); + printk(KERN_WARNING "Resume caused by more than %d IRQs\n", + MAX_WAKEUP_REASON_IRQS); + return; + } + + irq_list[irqcount++] = irq; + spin_unlock(&resume_reason_lock); +} + +int check_wakeup_reason(int irq) +{ + int irq_no; + int ret = false; + + spin_lock(&resume_reason_lock); + for (irq_no = 0; irq_no < irqcount; irq_no++) + if (irq_list[irq_no] == irq) { + ret = true; + break; + } + spin_unlock(&resume_reason_lock); + return ret; +} + +void log_suspend_abort_reason(const char *fmt, ...) +{ + va_list args; + + spin_lock(&resume_reason_lock); + + //Suspend abort reason has already been logged. + if (suspend_abort) { + spin_unlock(&resume_reason_lock); + return; + } + + suspend_abort = true; + va_start(args, fmt); + snprintf(abort_reason, MAX_SUSPEND_ABORT_LEN, fmt, args); + va_end(args); + 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); + irqcount = 0; + suspend_abort = false; + 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 + */ +int __init wakeup_reason_init(void) +{ + int retval; + + 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 1; + } + 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); + } + return 0; +} + +late_initcall(wakeup_reason_init); |