diff options
Diffstat (limited to 'kernel/power')
| -rw-r--r-- | kernel/power/Kconfig | 9 | ||||
| -rw-r--r-- | kernel/power/Makefile | 1 | ||||
| -rw-r--r-- | kernel/power/fbearlysuspend.c | 153 |
3 files changed, 163 insertions, 0 deletions
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index 625d653..a70f6c8 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -61,6 +61,7 @@ config EARLYSUSPEND choice prompt "User-space screen access" + default FB_EARLYSUSPEND if !FRAMEBUFFER_CONSOLE default CONSOLE_EARLYSUSPEND depends on HAS_EARLYSUSPEND @@ -74,6 +75,14 @@ choice Register early suspend handler to perform a console switch to when user-space should stop drawing to the screen and a switch back when it should resume. + + config FB_EARLYSUSPEND + bool "Sysfs interface" + depends on HAS_EARLYSUSPEND + ---help--- + Register early suspend handler that notifies and waits for + user-space through sysfs when user-space should stop drawing + to the screen and notifies user-space when it should resume. endchoice config HIBERNATE_CALLBACKS diff --git a/kernel/power/Makefile b/kernel/power/Makefile index 0d1c5e4..493f19d 100644 --- a/kernel/power/Makefile +++ b/kernel/power/Makefile @@ -12,5 +12,6 @@ obj-$(CONFIG_WAKELOCK) += wakelock.o obj-$(CONFIG_USER_WAKELOCK) += userwakelock.o obj-$(CONFIG_EARLYSUSPEND) += earlysuspend.o obj-$(CONFIG_CONSOLE_EARLYSUSPEND) += consoleearlysuspend.o +obj-$(CONFIG_FB_EARLYSUSPEND) += fbearlysuspend.o obj-$(CONFIG_MAGIC_SYSRQ) += poweroff.o diff --git a/kernel/power/fbearlysuspend.c b/kernel/power/fbearlysuspend.c new file mode 100644 index 0000000..1513765 --- /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); + |